Many authors have tried to explain how vast space, and the universe contained within it, really are, usually with less than total success, though with each attempt, some few are reached. This is both something that Sci-Fi GMs need to understand and yet, often hand-wave. I have thought of another approach, one that is strictly game-oriented. It may not work, but it’s worth a shot.

This is the latest in my series of time-out posts in between the Trade In Fantasy series.

There are three fundamental principles to my approach, and explaining them would be a good way to start. But I suspect that their meaning won’t be fully understood until we get into actual measurements, at which point hopefully it all becomes blindingly obvious.

1. A Nested Hierarchy Of Distance

Space is subdivided into a nested series of scales. Efficiency in transiting these scales requires new technologies each time the scale changes, though it is usually possible to employ a less-efficient transit technology – there is some overlap in principle.

The difficulties and hazards change as a new scale is reached, and these require navigational skills that match the engineering appropriate to that scale. I’m going to do my best to avoid actually spelling out the technologies concerned, leaving the system to be adapted to whatever sub-genre best fits the individual GM’s setting and campaign. This time around, for this particular GM, it might be some sort of interstellar Jump; next time, it might be Warp Drive; and so on.

2. A Fundamental Unit

The minimum distance of a scale is defined by the limit of the scale preceding it. Mastering the principles of this scale may or may not imply as a prerequisite the mastering of the preceding scale; different game systems will support different approaches to the question. Nor is it necessary or appropriate for this to be consistent; the greater the difference in technology required relative to what has gone before, the less transferable skills will be and the more likely a completely different approach required.

Fundamentally, each scale is measured in a new series of units, and the count of such units within the scale resets at ‘1’ each time.

3. Powers Of Five, or Two, or Three

The distances of a scale, measured in Units, require a technological / navigational improvement at regular intervals. each improvement level is known as a tech level or sub-level within the technology required for that particular scale. Each improvement permits maneuvering and transit at an exponential increase over the number of units.

CORRECTION: The following text, which originally followed the above, now needs to be taken with a grain of salt:

My default is going to be powers of five, because that’s what my instincts are telling me should work – but it may be necessary to employ other exponents along the way. I’ll do so as necessary.

In actual fact, i ended up using powers of 2, 3, and 4 a lot more than I did 5 – so much so that 3-exponent is probably best considered the default.

.

I don’t really want there to be more than a couple of handfuls of tech sub-levels within each scale, to keep the numbers manageable. My preference will be to introduce a new scale before ‘sub-level 21’ is reached – but, at the same time, I want each sub-level to achieve a noteworthy increase in the distances that can be transited.

All clear? I didn’t think so, but getting into the scales themselves should make everything fairly clear.

The Planetary Scale

Space starts at the Karman Line, defined as 100 km (62 miles) above sea level. This altitude defines the point at which aerodynamic lift can no longer be the primary means of flight and orbital mechanics takes over.

Anything short of this distance is a distance (vertically) on the Planetary Scale.

The unit at this scale is the Wright. One Wright is an altitude (powered flight) of 6.4m (21 feet).

Public domain image depicting the first flight by the Wright Brothers, courtesy of Wikimedia Commons.

Aircraft 1 = 1 Wright

The Wright Brother’s first flights were about 0.5 Wrights in altitude. The presumption is made that they stayed relatively flat and level to maintain control of the aircraft and could have actually flown higher – with greater risk of control loss.

Aircraft 2 = 5 Wrights = 32m

Aircraft 3 = 25 Wrights = 160m

Between 1906 and 1908, the altitude record was officially just 4m, or 0.625 Wrights. In the latter year, piloting a biplane, Wilbur Wright dramatically raised the record to 110m (17.2 Wrights), and 7 months later, this record was improved again to 150m (23.5 Wrights). It seems likely that at some point in between, a limit of 5 wrights was reached but no-one actually undertook an attempt.

Aircraft 4 = 125 Wrights = 800m

Late in 1909, another dramatic step forward saw the altitude record for powered flight increased to 920m.

Aircraft 5 = 625 Wrights = 4 km (13000 feet)

In 1910 the record increased multiple times, ending the year at 3497m. The next time it was reset was in 1912, to 5610m, another massive step forward.

It’s at this point that air travel becomes commercially viable for both cargo and passengers. The early steps were halting stumbles, but improvements in the technology followed, notably the DC3 and beyond.

After the heady rush of the early flights, and the steady progression of records being set and broken, this sub-scale would hold sway for many years; the technology was improved and refined, becoming more efficient and successful. It also seems likely that interest in altitude records per se declined in favor of speed records.

Aircraft 6 = 3125 Wrights = 20 km (65, 600 feet)

It wasn’t until 1949 that an aircraft exceeded 3125 Wrights in altitude, when an experimental air-launched rocket plane, the Bell X-1, did so, setting an unofficial record. Two years later, another unofficial record extended the window; it was not until 1953 that this limit was officially breached, when an English Electric Canberra B 2 Turbojet got to 20,079m. By now, the unofficial record (set with rocket power) was 27,570m and before the next non-rocket record was set in 1958, at 23, 451m, the rocket-powered or assisted record stood at 38, 491m.

(Aircraft 7 = 15625 Wrights = 100km (62 miles))

Everything in aviation since the early 1950s, in terms of altitude limits, falls into this sub-scale. Records past this time tend to split hairs – horizontal flight, crewed or unmanned, propeller-driven, and so on. What becomes more important at this scale is not the record altitude, but the cruising altitude.



Image by Julian Herzog via Wikimedia Commons. Released under the Creative Commons Attribution 4.0 International license.

The Boeing 747 Jumbo cruised at between 35,000 and 40,000 feet. The 767 added another 1,000 feet to the top of that. These are both Aircraft-5 ratings.

The cruising altitude of an airbus A320 is 31,000 to 37,000 feet. It has a service ceiling of 39,100 feet, the absolute maximum altitude that it can achieve. The A380 cruises at 43,000 feet.

Even Concorde only approaches the limits of Aircraft 5 in this respect, with a cruising altitude of 55,000 to 60,000 feet.

Beyond Aircraft 5, greater altitude requires special designs that are not commercially viable. The SR-71 Blackbird cruises at 85,000 feet (25,908m) and is a true Aircraft 6 design. Getting to Aircraft 7 requires rockets, and they operate even more efficiently at even higher altitudes.

If atmospheric pressure were greater, lift could be increased and greater altitudes might become possible, but wind resistance would also increase, and, honestly, you’re looking at a gimmick or marketing exercise or different technology (non-commercial) for most of Aircraft 6.

Aircraft 7 is the upper limit of this scale, as we transition to the Orbital Scale.

The Orbital Scale

From 100km up, we’re talking about the orbital scale, the unit of which is the Oberth. 1 Oberth = 100 km. Oberths use exponential powers of 4, not 5.

There can be other limits used. The US defines the Orbital Scale as starting at 50m (80km), for example.

Orbital 1 = 100 km – 400 km (1-4 Oberths)

Up until 400 km, significant air resistance will cause rapid orbital decay if unchecked. These altitudes are considered “Transatmospheric“. They are of limited practical value because of the air resistance, but may be used as a stepping-stone to higher orbital types.

This sub-level also includes terms such as “Very Low Earth Orbit” and “Suborbital” flight paths. Anything below 160km is generally considered Suborbital; VLEO orbits (160km-400 km) are used for Earth observation, radar, infrared, weather, telecommunications, and rural internet.



Artwork by Russ Arasmith for NASA depicting Project Gemini spacecraft and astronaut, date unknown. Image courtesy of Wikimedia Commons, public domain.

Orbital 2 = 400 km – 1,600 km (4-16 Oberths)

Low Earth Orbit has a very precise definition in terms of period (128 minutes or less) and eccentricity (less than 0.25). Most satellites are in Low Earth Orbit, peaking at around 800km in altitude – but LEO is considered to extend up to 2000 km, putting the outer reaches of LEO into the Orbital 3 sub-level.

Starlink satellites orbit at approximately 550 km, and are amongst the lowest LEO orbits in use.

The inner Van Allen radiation belt starts at around 1000km (10 Oberths) and extends to about 12000km (well into the Orbital 4 sub-level).

Orbital 3 = 1,600 km – 6,400 km (16-64 Oberths)

2000 km marks the entirely arbitrary dividing line between LEO and Medium Earth Orbit. MEOs extend all the way up to Geostationary Orbit (35,786 km). They are defined as having orbital periods of between 2 hours and 24 hours – and yes, that does create a small overlap with LEOs.

This subcategory falls completely within the Van Allen Radiation Belts. Other names for this type of orbit are Mid-Earth Orbit and Intermediate Circular Orbit.

The primary distinction between LEOs and MEOs is that the dominant cause of non-gravitational perturbations of the orbits is solar radiation pressure in an MEO, while atmospheric traces are dominant in an LEO.

This sub-level describes the lower region of MEOs.

When satellites in this sub-level reach the end of their operational life, it is generally cheaper to de-orbit them, permitting them to burn up in the atmosphere. The expectation of this mission terminus plays a critical role in designing those satellites, forbidding such things as nuclear power supplies.

Orbital 4 = 6,400 km – 25,600 km (64-256 Oberths)

The upper region of MEOs is contained almost completely within this sub-level. As such, it is relatively sparsely populated by satellites in comparison to sub-level 3.

The design restrictions on upper MEO satellites are far less restrictive because these are orbits it which it becomes cheaper to put satellites at their end-of-life into a graveyard orbit rather than letting them fall back to earth after a de-orbital maneuver.

Orbital 5 = 25,600 km – 102,400 km (256-1024 Oberths)

Anything aimed at Geostationary orbit that doesn’t quite get there is in the lowest part of this sub-level. Geostationary orbit itself is roughly Orbital 5.133. No orbit above this is considered stable.

A few hundred km further out is a region designated as a Graveyard orbit for defunct satellites; the thrust required to reach these orbits is a lot less than than that required to completely de-orbit a satellite.

Anything with an orbital period of a day or more is defined as being in High Earth Orbit, which are subdivided into a number of complicated designations: Geostationary (GEO), Geosynchronous (GSO), Geostationary Transfer Orbits (GTO), Highly Elliptical Orbits (HEO), and Near-Rectilinear Halo Orbits (NRHO). You don’t have to know what any of these are, really, aside from the obvious and well-known Geostationary and Geosynchronous.

GEOs remain in orbit above a fixed position on the Earth. GSO orbits do not, but they cycle back around to the same fixed point each day.

Satellites in these orbits are used for communications, navigation, scientific research, and of course, military applications.

All Orbits above 357.68 Oberths are eccentric to some degree. That means that they have a significant difference between perihelion and aphelion, the lowest and highest points of their orbit. Which means that periodically, the sun and moon will exert more gravitational force on them at other times because the orbital path will align with those bodies; this creates the instability referred to.

The maximum altitude of High Earth Orbit is another purely-arbitrary number. As the peak aphelion increases, so does the instability – with exceptions resulting from the mass of the orbiting object. There’s no danger of the Moon suddenly wandering off.

Local Interplanetary Scale

I define one unit on this scale as what would be Orbital 6, if such a thing existed, i.e. 102,400 km. I have named the units Lunars.

This scale also uses 4-exponential scale (actually, ideally, it would use exponential-3.5, but that’s too messy and complicated). The midpoint of gravitational attraction between earth and the moon depends on the relative masses – about 80-to-1 in the Earth’s favor, so the midpoint is roughly 1/80th of the distance.

The moon’s orbit has a minimum distance of 363,300 km; 79/80ths of this is 358,758.75 km. And that’s almost exactly 3.5 Lunars.

Oh well.

Local Interplanetary 1: 1 Lunar (102.4 Kkm) – 4 Lunars (409.6 Kkm)

The minimum distance from the earth at which a gravitational field other than that of the planet becomes dominant is, as stated, 358,758.75 km. That happens at 3.5 Lunars.

The moon has a maximum distance from Earth of 405,696 km (3.96 Lunars); the average is 384,400, which is often rounded down to 384,000 or up to 385,000 (because 600km difference at this scale is almost trivial). Call it 3.754 Lunars.

This scale is all about traveling from one planetary body to another, and the entire history of manned spaceflight (so far) is 4 Lunars or less.



Footprint of Buzz Aldrin on the moon. Public domain courtesy of Wikimedia Commons.

Local Interplanetary 2: 4 Lunars (409.6 Kkm) – 16 Lunars (1638.4 Kkm)

Earth-grazing asteroids and dangerous comets.

Local Interplanetary 3: 16 Lunars (1638.4 Kkms) – 64 Lunars (6.5536×10^6 km)

Not very much at all.

Local Interplanetary 4: 64 Lunars (6.5536×10^6 km) – 256 Lunars (2.62144×10^7 km)

Not very much at all.



Image by Wikipedia user Brian0918, Public Domain, courtesy of Wikimedia Commons, rotated & reoriented by Mike

Local Interplanetary 5: 256 Lunars (2.62144×10^7 km) – 1024 Lunars (1.05×10^9 km)

Venus, at its closest to earth, is 390.6 Lunars away.
Mars, at its closest, is 537.1 Lunars away.
Mercury is, at best, 752 Lunars away.

Local Interplanetary 6: 1024 Lunars (1.05×10^9 km) – 4096 Lunars (4.2×10^9 km)

The sun is 1362.3 Lunars away (=1 AU).

The Asteroid Belt sort of fades in and then fades out, without clearly-defined limits. The Core of the belt starts about 2.06 AU out and ends 3.27 AU out, so it straddles the change of scale. 2.06 AU is about 2812.6 Lunars away.

The 4096 Lunars limit of this sub-level is equivalent to 3.0068 AU – call it 3AU.

That’s long enough to reach a counter-earth (if there really was one) without cooking ourselves along the way.

Outer Interplanetary Scale

The boundary between inner and outer solar system is generally considered to be Jupiter. But that doesn’t quite fit our scale, so 1 unit of this scale is 3 AU. I have named these units Bouvards after the mathematician who predicted the planet Neptune from orbital irregularities of Uranus – because I don’t think he gets enough credit for his role in exploring the outer solar system.

From this point on, it becomes less relevant to think of the distance from Earth to an object and more relevant to consider the distance from the sun; by definition, this adds an error rate of ±1 AU, or 0.33 Bouvards, to the measurements.

I have chosen to use 3-exponential for this scale.

Outer Interplanetary 1: 1 Bouvard (3 AU) – 3 Bouvards (9 AU)

The outer edge of the core of the asteroid belt is 3.27 AU from the Sun, or 1.09 Bouvards.



This is an excerpt from a public domain image showing the relative sizes of the planets. Image courtesy Wikimedia Commons.

Outer Interplanetary 2: 3 Bouvards (9 AU) – 9 Bouvards (27 AU)

At its most distant, Jupiter is 3.957 AU or 1.33 Bouvards away from the Earth.

Saturn’s most extreme position is 10.27 AU or 3.42 Bouvards from the Earth.

Uranus is about 20.5 AU, or 6.83 Bouvards away.

That’s three of the four gas giants.

Outer Interplanetary 3: 9 Bouvards (27 AU) – 27 Bouvards (81 AU)

Neptune is about 30.06 AU out, or 10.02 Bouvards.



Image of the Kuiper Belt by the European Southern Observatory released into the Public domain, courtesy Wikimedia Commons.

From that distance and out to 50 AU (16.7 Bouvards) is the Kuiper Belt, and home to comets and dwarf planets like Pluto.

Outer Interplanetary 4: 27 Bouvards (81 AU) – 81 Bouvards (243 AU)

Nothing known.

Outer Interplanetary 5: 81 Bouvards (243 AU) – 243 Bouvards (729 AU)

Nothing known.

Outer Interplanetary 6: 243 Bouvards (729 AU) – 729 Bouvards (2,187 AU)

The inner edge of the Oort Cloud is just barely inside this range at 667 Bouvards.

Outer Interplanetary 7: 729 Bouvards (2,187 AU) – 2,187 Bouvards (6,561 AU)

Oort Cloud.

Outer Interplanetary 8: 2,187 Bouvards (6,561 AU) – 6,561 Bouvards (19,683 AU)

More Oort Cloud.

Outer Interplanetary 9: 6,561 Bouvards (19,683 AU) – 19,683 Bouvards (59,049 AU)

Still more Oort Cloud.

Outer Interplanetary 10: 19, 683 Bouvards (59, 049 AU) – 59,049 Bouvards (177, 147 AU)

The outer edge of the Oort Cloud is roughly thought to be 100,000 AU out (33,333 Bouvards) – but some estimates double that. Nevertheless, the outer limit of this scale is big enough to encompass most, if not all, of it.

The inner limit of this sublevel is 0.9337 light-years from Earth, and the outer is 2.8 light-years from Earth. You may also hear or read the term parsec used from time to time; 2.8 light years is 0.858484 parsecs.

This is the outer edge of our solar system, so far as we know. If Alpha Centauri has an Oort Cloud the size of the Earths (and we have no real reason to assume otherwise), it’s outer edge also falls into this sublevel (just barely) at 2.62 light-years or 55,253 Bouvards. Our Oort Clouds would be only 1.04 light years apart.

Unless the 200,000 AU people are right, in which case our Oort cloud would be partially inside theirs and vice-versa….

Local Interstellar Scale

2.8 light-years is one Romer, named for the first person to calculate the Speed Of Light in a Vacuum; Romer’s value stood for 54 years as the best that science could do. Sub-levels on this scale are 2-exponent.

Local Interstellar 1: 1 Romer (2.8 ly) – 2 Romer (5.6 ly)

Alpha Centauri, the closest significant star to Earth, is 4.2 light years away, right in the sweet spot for this range.

Local Interstellar 2: 2 Romer (5.6 ly) – 4 Romer (11.2 ly)

Barnard’s Star, the second-closest star to Earth, is in this sub-level. But so are 13 other stars, including Wolf 359 (well-known to Star Trek fans), Epsilon Eridani, and Sirius, the brightest star in the night sky. Between them, those 13 stars have 14 known or possible planets – so far.

Local Interstellar 3: 4 Romer (11.2 ly) – 8 Romer (22.4 ly)



A spatial representation of every star within 14 light-years of Sol. Image by Inductiveload, released into the public domain, courtesy Wikimedia Commons.

Alpha Canis Minoris (aka Procyon) – 11.4 ly.
61 Cygni – 11.4 ly.
Epsilon Indi – 11.9 ly.
Tau Ceti – 11.9 ly.
70 Ophiuchi – 16.7 ly.
Altair – 16.7 ly.
Alsafi (Sigma Draconis) – 18.8 ly.
Eta Cassiopeiae – 19.33 ly.
G Eridani – 19.7 ly.
Delta Pavronis – 19.893 ly.

Plus another 68 solar systems within 20 ly of Earth. And another 34 beyond that, the most significant of which are HD219134 and Xi Bootis, at 21.3 and 22 ly, respectively..

Local Interstellar 4: 8 Romer (22.4 ly) – 16 Romer (44.8 ly)

Vega – 25 ly.
Fomalhaut – 25.1 ly.
Pollux – 33.7 ly.
Arcturus – 36.7 ly.
Capella 42.9 ly.
And hundreds more.

Local Interstellar 5: 16 Romer (44.8 ly) – 32 Romer (89.6 ly)

Castor – 51 ly.
Aldebaran – 65 ly.
Regulus – 79 ly.
Mizar – 83 ly.
And thousands more.

Local Interstellar 6: 32 Romer (89.6 ly) – 64 Romer (179.2 ly)

Algol – 93 ly.
K2-18b -120 ly
Markab – 140 ly.
And thousands more.

Radio was invented in 1896, but the power was quite until part of the 1936 Olympics in Berlin were transmitted using an early TV transmitter. That signal has now traveled some 89 light years and has just entered this sub-level. If the earlier signals were detectable (not impossible), they are now 129 light years away and approaching the mid-point of the sub-level.



This is an artist’s impression of the Milky Way Galaxy according to the latest information we have, which I have edited to (a) drop in an enlargement, and (b) mark on that enlargement just how minuscule 129 light years is. Original image by NASA (public domain) courtesy Wikimedia Commons. If you can’t find it, I assure you that it’s there – but that rather proves my point, don’t you think?

K2-18b is significant because, from earth, we have been able to detect gasses in its atmosphere that so far as we know are only produced by simple life forms. That means that from that far away, our equivalents could detect life on earth through its chemistry. They would currently be looking at the earth as it was 120 years ago, in 2025-120=1905, by which time significant pollution would be in the atmosphere; sometime over the next 50 years or so, it would become completely clear that the place was either (a) extraordinarily unlikely, or (b) home to a technological civilization.

And that’s what this scale is all about. I’ve erred on the side of caution by suggesting that the signs of intelligent life might be detectable from even further out – the limits of the scale below are 358.4 ly, which would mean anyone observing earth would now be looking at the year 1666. I think that would be pushing credibility beyond breaking point, but somewhere between that and the 32 Romer lower limit of this sub-level, it becomes possible.

Local Interstellar 7: 64 Romer (179.2 ly) – 128 Romer (358.4 ly)

Izar – 202 ly.
Spica – 250 ly.
Bellatrix – 250 ly.
Canopus – 310 ly.
Acrux – 320 ly.

And probably tens of thousands more.

Regional Interstellar Scale

358.4 light years is one Herschel, named after the astronomer who did more to establish the shape of the galaxy than any other (even if he did get some details wrong).

The major difference between Regional Interstellar distances and Local Interstellar Distances is that we are more interested in noteworthy and unusual stellar phenomena and not so much in ordinary stars.

For the RI scale, I’m going back to 2-exponential because the distances involved here grow really big really fast, but anything larger is too coarse a measurement at low levels..

Regional Interstellar 1: 1 Herschel (358.4 ly) – 2 Herschels (716.8 ly)

The closest known Pulsar to Earth is 398 ly away – a mere 1.11 Herschels. The next closest is just outside this sub-level.

Betelgeuse is 408-548 or maybe 640 light years away. Everything in that distance is securely in this sub-level.

The Pleiades, one of the closest star clusters to Earth, is only 444 light years away.

Polaris is at a distance of 430 light years, while Antares is 550 light years.

At a distance of 610 light years is another cluster, the Beehive Cluster, which contains an astonishing 1000 or so stars, far more than is usual. Other sources place it even closer at 520 light years, but the consensus is currently moving closer to 600 or so.. It’s only about 23 light years in diameter.

Regional Interstellar 2: 2 Herschels (716.8 ly) – 4 Herschels (1,443.6 ly)

At 727 ly from Earth, the second closest pulsar can be found. It is also the most massive discovered to date. Two more pulsars and a Neutron Star also lie within this sub-level.

Rigel is 848±65 light years from Earth. 860 is the usual approximation.

Mintaka, the third of the stars in Orion’s Belt, is a six-star system 1200 light years from Earth. In combination, it’s six stars are around 250,000 times as bright as the sun.

Alnitak, one of the systems that make up Orion’s Belt, is 1260 light years away. It is a triple-star with the more distant member orbiting the other pair once every 1500 years.



Image by Zegery, released under the Creative Commons Attribution 4.0 International license, courtesy Wikimedia Commons.

The Orion Nebula, a well-known interstellar nursery, is 1344 light years from Earth. It’s actually an astonishingly small object, only about 25 light-years across.

Regional Interstellar 3: 4 Herschels (1,443.6 ly) – 8 Herschels (2,867.2 ly)

The closest known Black Hole is 1560 light years away, part of a binary star system. Another such pair is 1840 light years from us.

Alnilam, the second star of Orion’s Belt, is 2000 light years away. It’s the 29th brightest star in the Earth sky despite being much farther away than the others in the Belt.

There are two known pulsars in this sub-level, at 2055 and 2316 ly respectively. The latter is also named Lich after the Undead monster.



Image of the Ring Nebula by NASA’s Hubble Space Telescope (public domain), courtesy Wikimedia Commons.

The Ring Nebula in the constellation of Lyra is 2567 light years away.

Deneb, one of the most distant stars visible to the naked eye, is not much further at 2600 light years.

Regional Interstellar 4: 8 Herschels (2,867.2 ly) – 16 Herschels (5,734.4 ly)

3400 light years away is a supernova remnant; the explosion was reported by the Chinese in 393 CE and the remnant is now known as the Wei Asterism – there doesn’t seem to be a great deal left.

There is another pulsar 1060 parsecs (3457 ly) away. Three others also lie within this sub-level, and one more – the black widow pulsar – that might be.

The width of the galactic arm containing the sun, the Orion Arm, is 3500 light-years across. However, the Sun is quite close to the inner rim of the arm. Unfortunately, I couldn’t find an estimate for how close the nearer edge was. Still, since 1 Herschel is only 10.24% of the greater distance, it seems likely that it is one Herschel or less to that near boundary.

3800 light years finds another binary-star black hole, as does 4700 light years. At 5150 light years, there is an isolated black hole, and at 5400 light years, another binary pairing. Right on the edge of this sub-level is one more binary pair which includes a black hole, 5720 light years away..

The distance to the next nearest galactic arm (Carina-Sagittarius) is estimated to be 1400 parsecs or 4566.2 light years.

Some of the closest super-massive stars to Earth can also be found in this sub-level. There’s HD229059 (69 Suns) at 3,000 light years, Trumpler 27-27 (81 Suns) at 3900, Trumpler 27-23 (64 suns) also at 3900, HR6187A (63 suns) at 4300, and 5 more. The most distant of them is 5400 light-years away, and it is considered a Runaway Star from Cygnus OB2, a very young star cluster that is one of the largest known (ten times more massive than the Orion Nebula), which at 5120 light years, is also to be found in this sub-level.

Regional Interstellar 5: 16 Herschels (5,734.4 ly) – 32 Herschels (11,470 ly)

At 5900, 6500, and 7500 light years, there are another 11 supermassive stars. There’s also HD190429A at 7800 ly, HD93160 at 8,000, WR22A at 8300, HD303308 at 9200, two more at 10,000, one at 10,400, and no less than four at 11,000 light-years.



A mosaic of multiple images taken by the Hubble Space Telescope (NASA, public domain) of the Crab Nebula. Image courtesy of Wikimedia Commons.

This sub-level also contains five more Pulsars, including the Crab Nebula Pulsar and Cosmic Cannonball, which is moving away from the supernova remnant at 672±115 km per second, making it one of the fastest-moving stars every found – though initial estimates of its speed were an even higher 1500 km/s. At the moment, our theories don’t explain how it’s possible for a supernova to induce such speed.

The closest galactic arm on the other side of the Orion arm (the Perseus Arm) is about 6400 light years away, down from older estimates of 13,000 light years.

At 7,300 light years, 7,800 light years, 8100 light years, 8800 light years, and 11000 light years there are binary systems with black holes. At 8150 and 9260 light years are isolated Black Holes. The 7,300 light-year system is perhaps the most famous of these, Cygnus X-1.

Regional Interstellar 6: 32 Herschels (11,470 ly) – 64 Herschels (22,940 ly)

The Orion Arm is relatively short at 20,000 light years in length. This distance is enough to go from one end of it to the other.

There are 5 known pulsars and neutron stars within this sub-level.

V762 is the most distant individual star that can be seen from Earth with the naked eye at 16000 light years removed. It’s an absolutely massive variable star that is about 100,000 times as luminous as the sun.

Intergalactic Scale

Even a galaxy or galactic object that is not so far away (as galaxies go) is a LONG way away from Earth. This scale encompasses the entirety of the Milky Way and the nearest such collections of objects. I have decided to name this unit the Messier. Once again, I’ve found it more useful to use 3-exponential for this scale.

I also think it worth quoting the caveats given on the Wikipedia page, List of Nearest Galaxies:

“….aims to reflect current knowledge: not all galaxies within the 3.8 Mpc radius have been discovered. Nearby dwarf galaxies are still being discovered, and galaxies located behind the central plane of the Milky Way are extremely difficult to discern. It is possible for any galaxy to mask another located beyond it. Intergalactic distance measurements are subject to large uncertainties. Figures listed are composites of many measurements, some of which may have had their individual error bars tightened to the point of no longer overlapping with each other.”

In other words, this is the best information we currently have but a lot of it remains uncertain and subject to change. Some galaxies currently thought to be part of the local group may be de-listed, others now thought to be part of a neighboring group may be welcomed to the neighborhood, and distances can be radically altered as better information comes in.

Most of all, the number of galactic objects at a given distance is subject to massive revision. Right now, we haven’t even identified all the phenomena that we should be listing!

It is also worth remembering when perusing the lists that follow that only four galaxies are visible to the naked eye from Earth. Four.

Intergalactic 1: 1 Messier (23K ly) – 3 Messiers (69K ly)

The Galactic Core is 26,000 light years from Earth.

The outer edge of the Milky Way is about 27,000 light years from Earth on the closer side.

Intergalactic 2: 3 Messiers (69K ly) – 9 Messiers (207K ly)

70,100 light years gets you to Draco II, one of the closest and dimmest known galaxies.

75,000 light years away is another close neighbor galaxy, Segue 1.

The outer edge of the far side of the Milky Way is about 77,000 light years away.

The Sagittarius Dwarf Spheroidal Galaxy is 78,000 light years from us.

The Dwarf Galaxy Hydrus I, is 90,000 light-years away. 90,700 light years in a different direction will take you to either the Carina III dwarf.

Travel 98,000 light years and you reach the Ursa Major II Dwarf Galaxy. Or the Triangulum II Dwarf Galaxy, if you go in that direction instead.

102,000 light years away is the Reticulum II Dwarf Galaxy.

The entire Milky Way galaxy is 106,000 light years across.

Between 107,000 light years and 157,000 light years are 9 other galaxies, of which the most notable is Willnan 1 at 124,000 light years, which is an ultra low0-luminosity galaxy – in other words, it’s much darker and dimmer than usual.



Image of the Tarantula Nebula taken by the James Webb Space Telescope (NASA, public domain) courtesy Wikimedia Commons.

The Large Magellanic Cloud is 163,000 light years away. The Tarantula Nebula forms the Southeastern corner of the cloud (from our perspective), and is home to a huge number of supermassive stars, including the largest single star ever discovered at 196 Suns.

Two more galaxies are located at 179K and 186K light years respectively. At 197K light years, you will find Bootes I, which used to be a dwarf galaxy but which appears to have been torn apart – “disrupted” is the official term – by the Milky Way. Intergalactic Road-kill.

The Small Magellanic Cloud is 205,000 light years away, as is the Ursa Minor Dwarf Galaxy.

Intergalactic 3: 9 Messiers (207K ly) – 27 Messiers (621K ly)

At distances ranging from 235K to 258K light years are 7 minor galaxies.

The Pisces Overdensity is a clump of stars of uncertain history – possibly a disrupted dwarf Galaxy, perhaps not. It’s 260,000 light years away.

Between 267K light years and 326 light years are 9 minor galaxies. 330,000 light years takes you to the Carina Dwarf Galaxy.

Between 333 and 466 light years distance are 10 more minor galaxies.

490,000 light years away from us is the Cenes Venatici II Dwarf Galaxy.

You find another 6 minor galaxies between 492K light years and 597K distance from Earth.

Intergalactic 4: 27 Messiers (621K ly) – 81 Messiers (1.863×10^6 ly)

From 682K light years to 820K light years are another 6 minor galaxies.

The Milky Way is surrounded by a dark matter halo at a distance from the galactic center of 952,000 light years.

Beyond that, another 7 minor galaxies can be located within this sub-level.

Intergalactic 5: 81 Messiers (1.863×10^6 ly) – 243 Messiers (5.59×10^6 ly)

This sub-level takes us into the more remote parts of the local group, and a few galaxies which are not part of that group. It was the latter that signaled that it was time to change scales once again.

The nearest such galaxy is Cassiopeia 1, an isolated galaxy located 5.19 M light years from earth. Between us and that distance are 58 other galaxies, including two of the three largest in the local group – the Andromeda Galaxy at 2.5 M light years and the Triangulum at 3.2 M light years.



Everyone’s seen pictures of the Andromeda Galaxy, so I thought I’d do something different. This is an image of the Triangulum Galaxy by Nielander and released to Wikimedia Commons under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

Beyond Cassiopeia 1 but within this sub-level is one more galaxy, Leo P, a small star-forming irregular galaxy first discovered as an ultra-compact high velocity cloud of Hydrogen Gas.

Transgalactic Scale

While there are still some of the more distant members of the local group in the early sub-levels, increasingly this scale is about larger structures within the universe, which we are only just beginning to understand.

At this distance, we don’t yet know what’s interesting and what’s routine. Rather than populate the individual sub-levels with irrelevancies, I’ll just pop in a few landmarks.

For this scale, the units have been named Hubbles (one Hubble = 5.6 M ly) and 5-exponential is the progression.

Transgalactic 1: 1 Hubble (5.6 M ly) – 5 Hubbles (28 M ly)

97 galaxies lie between 1 and 2.2 Hubbles, which is as far as Wikipedia’s table took me. The most distant member of the Local Group is either Leo P (see above) or possibly IC5152 at 5.68 M light years.

This sub-level therefore contains the entire Local Group, less than 1.0143 Hubbles wide.

Transgalactic 2: 5 Hubbles (28 M ly) – 25 Hubbles (140 M ly)

53.8 M ly takes you to the center of the Virgo Cluster. The Cluster contains 1300+ galaxies, possibly as many as 2000. It is

“…an aggregate of at least three separate subclumps: Virgo A, centered on M87, a second centered on the galaxy M86, and Virgo B, centered on M49, with some authors including a Virgo C subcluster, centered on the galaxy M60 as well as a Low Velocity Cloud (LVC) subclump, centered on the large spiral galaxy NGC 4216.

M87 is a giant elliptical galaxy which contains a supermassive black hole. It’s subclump is the dominant one of the entire Cluster, and it is about ten times the mass of the others. The three subgroups are in the process of merging into a single cluster, and are surrounded by isolated galaxies and galactic groups that are gravitationally bound to (and therefore part of) the Cluster, and which are likely to be absorbed at some point in the future.

Our Local group is neighbors to the Virgo Cluster but not a part of it (and it took a lot of research to discover that, for reasons that will become obvious).

The Formax Cluster is 62 M ly from earth; the Antilia Cluster is 133 ly away.

75 M ly from earth is the possible center of the Local Void, a region that starts at the edge of the Local Group and extends for another 150 M or 490 M or 980 M light years (the far edge is a bit fuzzy in definition)! This region has significantly fewer galaxies than normal.

The Virgo Supercluster, which contains more than 100 galaxy groups including the Virgo Cluster and Earth’s Local Group, has a diameter of 110 M ly. This Supercluster is one of about 10 million in the observable universe.

Transgalactic 3: 25 Hubbles (140 M ly) – 125 Hubbles (700 M ly)

A 2014 study found that the Virgo Supercluster is itself a component of a still larger group, Laniakea, which is centered on the Great Attractor. Laniakea contains about 100,000 galaxies. The lowest estimate for the distance to the Great Attractor is 150 M ly, and the highest is 250, so it is definitely a feature of this sub-level.

In fact, the span of the Laniakea Supercluster is about 500 M ly along it’s longest axis, so it also fits comfortably, in it’s entirety, within this sub-level.

Laniakea is in turn part of a larger structure, the Pisces-Cetus Supercluster Complex, also known as a Galaxy Filament. It is adjacent to the Perseus-Pegasus Filament. The PC Supercluster Complex is about 150 M ly wide.

The Centaurus Cluster is 171 M light years away.

The Hydra Cluster is 190 M light years away.

Transgalactic 4: 125 Hubbles (700 M ly) – 625 Hubbles (3.5 B ly)

The PC Supercluster is long and thin in shape – so much so that you have to go to this entirely new sub-level to contain it. It has an estimated length of 1 B ly, making it one of the largest structures in the observable universe.

The Sloan Great Wall is 1.3 B ly in size and is basically a wall of galaxies. If you think of the universe as a whole heap of soap bubbles (voids) connecting to each other, walls and filaments are the soap of the bubble.

Clowes-Campusano LQG is 2 B ly in size – it’s a group of 34 quasars.

U1-11 LQG, another group of quasars is 2.5 B ly.

Only two structures in the observable universe are known to be larger than these.

Transgalactic 5: 625 Hubbles (3.5 B ly) – 3125 Hubbles (17.5 B ly)

The first of those larger structures is the Huge-LQG, a 4 B ly -across quasar group, with 73 quasars.

But the winner (at least at the moment) is the Hercules-Corona Borealis Great Wall, a Galaxy Filament that is 10 B ly in length, and 9.6-10.5 B light years away.

Transgalactic 6: 3125 Hubbles (17.5 B ly) – 15625 Hubbles (87.5 B ly)

Or maybe it’s 15-17.675 B light years – if you factor out the expansion of the universe.

Transgalactic 7: 15625 Hubbles (87.5 B ly) – 78125 Hubbles (437.5 B ly)

The Observable Universe is about 93 B light years (16,607 Hubbles) in diameter. Beyond that, science claims, it’s impossible to know anything about what’s there – it doesn’t exist so far as we’re concerned.

Summary

So there you have it.

• The Planetary Scale: Aircraft 1, 2, 3, 4, 5, and 6 from 1-16525 Wrights.
• The Orbital Scale: Orbital 1, 2, 3, 4, and 5, from 1 to 1024 Oberths.
• The Local Interplanetary Scale: 1, 2, 3, 4, 5, and 6, from 1 to 4096 Lunars.
• The Outer Interplanetary Scale: 1,2 ,3, 4, 5, 6, 7, 8, 9, and 10, from 1 to 59049 Bouvards.
• The Local Interstellar Scale: 1, 2, 3, 4, 5, 6, and 7; from 1 to 128 Romer.
• The Regional Interstellar Scale: 1, 2, 3, 4, 5, and 6; from 1 to 64 Herschels.
• The Intergalactic Scale: 1, 2, 3, 4, and 5, from 1 to 243 Messiers.
• The Transgalactic Scale: 1, 2, 3, 4, 5, 6, and 7; from 1 to 78125 Hubbles.

6(+1)+5(+1)+6(+1)+10(+1)+7(+1)+6(+1)+5(+1)+7 = 59 exponential increases to define the observable universe and the distance to anything and everything within it.

If I had used 2-exponential throughout, that would be 2^59 = 576,460,752,303,423,488 times the original 1 Wright.

If I had used 3-exponential throughout, that would be 3^59 = 14,130,386,091,738,734,504,764,811,067 times 1 Wright.

But, in fact, I used 2 sometimes and 4 or 5 sometimes. Nevertheless, it’s a totally preposterous number that I refuse to have anything more to do with.

59 Skill or Tech levels to define the ability to navigate anywhere in space.

The universe is thought to be 4.35 x 10^17 seconds old. If I divide that by 2^59, the matching precision for time travel would be 0.7546 seconds being the equivalent of 1 wright. But that’s only the past – what about the totality?

27.0 seconds – based on the most pessimistic estimate of the remaining lifetime of the universe. It well could be longer.

Models of Skill

I would contend that navigating at the planetary scale is a completely different problem to navigating in space, and that navigating interstellar distances in any practical way is also a fundamentally different practice. You might disagree, but play along for a minute until you see where I’m going with this.

If your current technology is measured, say, in Romer – which is what I would consider to be the case in Traveler, to name one game system – then you have Interstellar Navigation and Interstellar Engineering as the basic skills. The next smallest scale, Bouvards, is considered a freebie, a simpler subset of the Romer skills.

Local Interplanetary Navigation and Engineering is a separate skill, and gives you the next smaller one – Orbital – as a freebie.

That takes you down to basic aerial navigation at the planetary scale.

Okay, but what if you’re more advanced than that? Let’s talk Star Wars, and Herschel-scale skills.

Regional Interstellar Engineering (better known in this case as Hyperspace Drive Engineering) and Navigation covers Herschels.

You get the next smaller scale, Romers, free. They are considered a subset of the skills already listed.

You have to Buy Bouvard-scale Engineering and Navigation, probably described as Planetary-system Navigation and Sub-light Drive engineering.

That gives you both Inner and Outer system skills, because you get the next smaller scale for free, as usual.

Orbital is the next one that’s not covered, so you have Thrusters Engineering and Orbital Astrogation skills. But they give you the next scale down for free, and that’s the planetary scale, and ordinary Navigation.

This basic methodology means that most campaigns will define two or three engineering skills (to cover the maintenance and repair of wildly differing technologies) and two or three navigational skills to let you plot a course to where you are going.

Throw in the following:

The tech level within a Scale defines how far you can safely transit without incurring systems damage. Experimental systems may permit one additional step or may act to increase the reliability of the existing systems. Navigational skills cannot exceed the tech level; any additional skill levels beyond this limit provide a +1 to skill checks without increasing the skill description that you have. So Warp Drive Engineering (for a Star Trek campaign) 3+3 means that you can navigate up to 8 Herschels, and get +3 on your chances to do so. Smaller trips also add bonuses – so if you’re only going 4 Herschels, you’re only using skill 2, leaving an extra +1 for your rolls.

…and what you have is a universally-adaptable skill subsystem for the maintenance and navigation of any distance throughout the universe. If a trip is longer than you can navigate, you have to break that trip into smaller chunks and plot new courses when you reach the end of each stage of the journey.

The exponential increases in distance mean that it isn’t and should not be easy to go from one tech sub-level to the next. It will take time and technological improvements. Going from one scale to another may involve whole new technologies, even if you’re measuring them on the same old scale – being able to go from Warp Factor 3 to Warp Factor 5 as a top speed, for example.

So let’s end with this: the defined units (not all of which will be used in every campaign).

1 Wright = 6.4 m (21 feet).
1 Oberth = 15625 Wrights= 100km.
1 Lunar = 1024 Oberths = 102,400 km.
1 Bouvard = 4096 Lunars = 3 AU
1 Romer = 59049 Bouvards = 177,147 AU = 2.8 ly.
1 Herschel = 128 Romer = 358.4 ly
1 Messier = 64 Herschels = 22, 940 ly
1 Hubble = 243 Messiers = 5.59 M ly
16,607 Hubbles = the observable universe.

9 units – ten, if you count the meter or the foot – to define reality. My work is done.

Weather At Sea can be considered to comprise several of the unluckiest things that can and will happen to a ship, so it’s somewhat appropriate that this is the dominant subject of the thirteenth part of this series!

Believe it or not, the entire weather system presented in the post was designed on a single sheet of notepaper…

Table Of Contents: In part one of Chapter 4: Modes Of Transport

4.0 A Word about Routes

4.0.1 Baseline Model
4.0.2 Relative Sizes
4.0.3 Competitors
4.0.4 Terrain I
4.0.5 Terrain II
4.0.6 Multi-paths and Choke Points

4.0.6.1 Sidebar: Projection Of Military Force

4.0.7 Mode Of Transport

4.1 Backpack / Litters / Shanks Pony

4.1.1 Capacity
4.1.2 Personalities / Roleplay

4.2 Horseback

4.2.1 Capacity
4.2.2 Requirements
4.2.3 Personalities / Roleplay

4.3 Mule Train

4.3.1 Capacity
4.3.2 Requirements
4.3.3 Personalities / Roleplay

4.4 Wagons

4.4.1 Capacity
4.4.2 Requirements
4.4.3 Other Exceptions – Animal Size

4.4.3.1 Sidebar: Road Trains

4.4.4 Fodder / Food & Water Needs

4.4.4.1 People
4.4.4.2 Horses
4.4.4.3 Mules
4.4.4.4 Oxen / Cattle
4.4.4.5 Elephants
4.4.4.6 Other

4.4.5 Personalities / Roleplay

In Part 2:

4.5 River Boats & Barges

4.5.0 A Splice Of Maritime History

4.5.0.1 Dugouts & Canoes
4.5.0.2 Rafts
4.5.0.3 Boats
4.5.0.4 Poled Rafts & Barges
4.5.0.5 Oars
4.5.0.6 Land-based motive power
4.5.0.7 Sail
4.5.0.8 Better Sails
4.5.0.9 Trading Ships
4.5.0.10 Warships & Pirates
4.5.0.11 Beyond the age of sail
4.5.0.12 Riverboats
4.5.0.13 Sources

4.5.1 Riverboat Capacity
4.5.2 Favorable Winds

4.5.2.1 The Beaufort Wind Scale

4.5.3 Favorable Currents
4.5.4 Unfavorable Winds / Currents – Oarsmen Requirements
4.5.5 Unfavorable Winds / Currents – Sail Solutions
4.5.6 Extreme Weather Events
4.5.7 The Tempest Scale
4.5.8 Vessel Rating
4.5.9 Weather Cataclysms

In Part 3:

4.6 Rafts

4.6.1 Rowing Time & Exhaustion
4.6.2 The basics of vector sums

4.6.2.1 An Example
4.6.2.2 A better example
4.6.2.3 With Maths
4.6.2.4 Simplified Vector Sums
4.6.2.5 Multi-hour Vector Sums

4.6.3 Raft Design & Operation

4.6.3.1 Buoyancy
4.6.3.2 Raft Calculation Process
4.6.3.3 Why all this matters
4.6.3.4 Category 1 Raft Table
4.6.3.5 Category 2 Raft Table
4.6.3.6 Category 3 Raft Table
4.6.3.7 Category 4 Raft Tables
4.6.3.8 Category 5 Raft Tables
4.6.3.9 Category 6 Raft Tables

4.6.4 Overloaded Rafts
4.6.5 Raft Breakup
4.6.6 Construction Time
4.6.7 A final word on Overloading Capacities

4.7 Canoes etc

4.7.1 Proportions
4.7.2 Frontal Dimension
4.7.3 Base Speed

In Part 4:

4.8 Seagoing Vessels

4.8.0 Logistics At Sea and In Space

4.8.0.1 “But I don’t need to know this stuff, my PCs aren’t Space Traders…”
4.8.0.2 Using the analogy
4.8.0.3 A Word on Historical Accuracy

4.8.1 Capacity
4.8.2 Ships As Monsters
4.8.3 Ship Specifications

4.8.3.1 Physical Dimensions
4.8.3.2 Movement Parameters
4.8.3.3 Functionality
4.8.3.4 Combat
4.8.3.5 Data Sources
4.8.3.6 Ship Specifications

4.8.4 Some Thoughts About Cannon

4.8.4.1 Having Your Cannon And Your Flavor, Too
4.8.4.2 Crippled Land-Cannon
4.8.4.3 Personal Firearms
4.8.4.4 Bombs and other explosive devices

4.8.5 Exotic Crews

4.8.5.1 Human Height Adjustments
4.8.5.2 Non-human Height
4.8.5.3 Non-human Proportions
4.8.5.4 Crew Strength
4.8.5.5 Handling and other parameters

4.8.6 Mixed Crews

Today’s post:

4.8.7 Weather At Sea

4.8.7.1 An Introduction to Weather (oversimplified)
4.8.7.2 Accumulated Potential and Threshold
4.8.7.3 Process Overview
4.8.7.4 Climate Baselines
4.8.7.5 Seasonal Weather Trends
4.8.7.6 Long and Short Base Thresholds
4.8.7.7 Daily Temperature Variation
4.8.7.8 Weather Change Threshold
4.8.7.9 Trend
4.8.7.10 Result Totals
4.8.7.11 Interpretation
4.8.7.12 Severity

     4.8.7.12.1 Extending The Example

4.8.7.13 Clouds & Rain
4.8.7.14 Winds

     4.8.7.14.1 Wind Speed
     4.8.7.14.2 Ship Speed vs Wind Speed
     4.8.7.14.3 Wind Direction
     4.8.7.14.4 Wind Duration
     4.8.7.14.5 Favorable Winds
     4.8.7.14.6 Becalmed
     4.8.7.14.7 Unfavorable Winds
     4.8.7.14.8 Violent Winds
     4.8.7.14.9 Extreme Winds: Hurricanes etc

4.8.7.15 Currents

     4.8.7.15.1 Favorable Currents
     4.8.7.15.2 Still Currents
     4.8.7.15.3 Unfavorable Currents
     4.8.7.15.4 Violent Waves
     4.8.7.15.5 Extreme Waves: Tsunamis & Walls Of Water
     4.8.7.15.6 Unfavorable Winds / Currents – Oarsmen Requirements
     4.8.7.15.7 Unfavorable Winds / Currents – Sail Solutions

4.8.8 Currents & Waves

4.8.8.1 A brief note on Sea Anchors
4.8.8.2 Favorable Currents
4.8.8.3 Still Currents
4.8.8.4 Unfavorable Currents
4.8.8.5 Violent Waves
4.8.8.6 Extreme Waves: Tsunamis & Walls Of Water

4.8.9 Other Applications of the Weather System

4.9 Exotic Modes Of Transport

4.9.1 Flight
4.9.2 Teleport
4.9.3 Magic Gates & Portals

And, In future chapters (most of them much shorter):

5. Land Transport
6. Waterborne Transport
7. Spoilage
8. Key Personnel
9. The Journey
10. Arrival
11. Journey’s End
12. Adventures En Route

4.8.7 Weather At Sea

Weather at sea is a lot more stable than weather over land. You see, on land there is uneven heating of the surface, there are obstacles to shape and redirect wind, there’s a much greater potential for dust to be carried into the air where is catalyzes rain or thunderstorms or hail.

At sea, weather gets pushed around a bit and generally finds nothing but more water. Weather systems build and build until one of three things happens: high-level winds carry dust from land, triggering whatever has built up, or the weather system makes landfall, triggering whatever has built up, or the buildup finally exceeds the capacity of the local atmosphere and everything that has built up takes effect.

Weather phenomena are all interconnected directly as well as indirectly. One of those interconnections is the movement of weather fronts and changes in barometric pressure that accompany them. The greater the pressure differential, the stronger the airflow from high pressure into low.

Another way of thinking about weather is as the movement of air – be it hot or cold. Hot air can hold a lot of moisture, cold air not so much.

I think I was about four years old when I became aware that there are semi-predictable patterns to the weather. Those patterns seemed so simple and clear at the time – and everything that I (and mankind) have learned since have only complicated the situation.

Nevertheless, I hope to dumb it down, simplify it to the point where a workable game mechanic can be extracted, just for use at sea.

4.8.7.1 An introduction to Weather (oversimplified)



Take a look at the 8-panel illustration above.

★ In panel one I have quickly generated two landmasses, some islands, a volcano, and a lot of ocean. There’s also a ship in the middle of the panel, about 1/3 up, for no particular reason.

★ In panel two, I have added an equator (solid line), a couple of tropics, and an arctic region.

★ Panel 3 shows what most people expect to happen weather-wise – hot air rises in the tropics and moves north and south of the equator. Sorry to anyone who thought that – you have half of the story backwards. Hot air rises, true enough, but that lowers the air pressure, so cool air rushes in to the tropics from the cooler regions. Assuming that the planetary rotation is in the right direction, the arrows at the top of the panel should be at the bottom and vice-versa.

Is the planetary motion in the right direction? Well, the winds are moving west to east, so the planet is moving east to west, and if you picture that by rotating anything round, you’ll find that it means that the sun rises in the West and sets in the East.

Uh-oh. Either this planet rotates in the opposite direction to the Earth, or the top of the map is South and not North for some reason. The second choice is the simpler explanation, so some reason for the inversion has to be invented; I can think of several, but that’s neither here nor there.

★ In the daytime, both the land and the water heat up, as shown by panel 4. Convection currents carry some of the heated water down, replacing it with cooler water. The only places that don’t warm much at all are the snow-capped mountain peaks, which reflect more of the heat away.

That means that all day on a warm day, the air pressure over land is going down; when the sun dips low enough, the expansion of the air stops being enough to hold back the cooler air that wants to fill that partial vacuum, and you get a (relatively) cool sea breeze, something that I have enjoyed on many an occasion.

★ Panel 5 offers a heat-map of what then happens at night. The heat of the land and shallow waters is quickly radiated away (unless there’s significant cloud cover to reflect it back down). So the land cools off relatively quickly. But the oceans have been sequestering heat all day, becoming an enormous heat bank, but now the tables have turned and that heat is being given off, and taking evaporated water vapor with it.

When that water vapor hits land, it will condense into clouds. For that reason, most coastal cities experience early morning cloud cover most days; the sky doesn’t become clear until this burns off. How long this takes is a complicated question I don’t pretend to have an answer to; Here in Sydney, cloud cover burns off somewhere between 8AM and 10AM, but I once visited Los Angeles after they had their smog problems in hand, and the cloud cover still didn’t burn off until about 3PM local time!

My only hint is that I think local wind patterns have something to do with it, because I have read of this aspect of the weather being affected by Heat Islands. What’s a heat island, you may ask? Concrete and bitumen and asphalt absorb more heat than grass-covered natural areas, so every city absorbs more heat than the lands around it, which creates an island of high heat in a sea of moderate temperatures. This heat then impacts the local weather.

This is an extremely complicated field of study; another building blocking the light can have significant ramifications that aren’t recognized until it gets knocked down. And that’s without factoring in the concrete-canyon wind-tunnel effects!

But we still have the planetary rotation to take into account. The heat from a land mass will bloom outward to the West (that’s to the right on our map), and that will create low pressure systems off the western coast. As a general rule, though, there’s a lot of room out there for them to dissipate – unless they strike another landmass in the meantime.

Sometime overnight, then, the sea breeze will dissipate and be replaced with a breeze blowing from on-shore.

★ Panel 6 shows how complicated weather can get as a result of these simple contributors. Air flows(with moisture) from the middle of the ocean each night, carried along by sea breezes that head for the nearest land – but which are then twisted around by the planetary rotation, and pulled this way and that by other factors.

Who here remembers Biorhythms? This pseudo-science idea was popular in the late 70s because a computer was really good at calculating them and putting the results up on the screen. Ultimately, this was all about the simultaneous charting of three sin waves with different periods (23, 28, and 33, respectively), and summing them to produce a compound curve which can exhibit considerable complexity, like this:



Created using Desmos Tools and licensed under the Creative Commons “Attribution-ShareAlike” License (CC-BY-SA-4.0)

Well, weather is a bit like that – but the period (length of a cycle) and the amplitude of that cycle are both semi-randomly variable. Make a note of that point, it will become important when I get to the game mechanics.

The last thing to note before I move on is that there are already (unstable) indications of a circular airflow forming. If enough energy (in the form of heat) builds up in such a system – something that typically only happens in summer – and if there is enough moisture in the air to absorb and retain that energy, then you can end up with a hurricane or tornado or whatever you want to call it.

★ Panel 7 illustrates the complex compounding of movements of air masses that can result. It’s basically a Vector Sum but you don’t move in a straight line to the result, you move in a curve that touches the constituent vectors. The first one is the wind speed, the second one is the rotation of the world, and the resulting rotation of the air mass, and the third is the attractive properties of the nearest piece of land to the sum of the first two.

★ Finally, Panel 8 shows what happens as a result. A cold front – a mass of moist air in a low-pressure environment – has formed. It gets moved around by the wind along the path indicated. If more cold air joins the existing mass, the cold front gets bigger; if not, it gets smaller. And it’s motion is such that the direction of the wind Vector Sum is always at right angles to the cold-front – in this case, the bottom of the front doesn’t have to move as fast as the top, which causes the cold front to become more curved and to head back towards the source of the cold air, where it will have every chance of hooking up with more cold air.

But there is a landmass in the way, and that will cause it to lose a lot of the moisture (and the energy contained within it) as rain, hail, thunder, and lightning. The time of day and time of year are obviously critical – you don’t normally get offshore winds in the head of the day; if anything, you get the opposite, and that means that the cold front ‘stalls’ out to sea. That could be a bother to a ship, but it’s a desirable outcome for anyone living near the coast of the landmass in question. When the winds shift, the front will start to move very quickly toward land.

It’s not unreasonable to take the basic winds of panel 3 and add in the complications of other winds and pressure systems to get the basic track that a front will follow.

4.8.7.2 Accumulated Potential and Threshold

There are two variables at the heart of the Weather Mechanics that I am going to propose. The first is the Accumulated Potential for a change in the weather, and the second is the threshold that this potential has to reach before that change actually happens.

Potential will keep accumulating until something happens to discharge it. Once it starts, a random roll resets both potential and threshold.

Any weather event can be thought of as ‘the absence of the opposite condition’, at least in general terms. If a forecast indicates no cloud, there is no chance of rain, and the result is a sunny day. If a forecast is for heavy cloud cover, there is every chance of rain, and the result is a pronounced absence of sunshine. Any given day can either be ‘stable’ in it’s forecast or ‘transitional’ / changeable / unstable.

Some seasons are more prone to instability than others – the patterns depend on where you are but as a general rule, winter is more stable than spring and autumn, both of which are more stable than summer, because one of the key drivers of instability is energy, which is more plentiful in summer. However, this generally means that most weather events in summer are short and transitory; only a few will last more than a day, and most will last only a few hours (temperature trends excepted). However, summer is also prone to these disruptions being short and sharp – in winter, the miserable weather can be consistent for many days.

The situation is a bit different in tropical regions. They only really have two seasons – the wet season (which is Summer everywhere else, plus half of autumn and half of spring) and the dry season (the rest of the time). In the rainy season, the normal pattern is hot, humid, and sunny until sometime in the afternoon – the times will vary – when it will absolutely teem down for one or two hours. The earlier in the day this happens, the bigger the downpour will be the next day, simply because there’s been more time for the humidity to accumulate.

Disruptions to this norm still happen – you might get the rain event in the late morning instead of the afternoon, or the early evening, or even not get one at all for a day or two. Or it might rain all day for a day or two – not teeming down as heavily but still solidly wet weather. In the mountains, even in the tropics, in winter, you might get still snow or hail.

4.8.7.3 Process Overview
In writing this section, I came up with a completely new weather generation system. I’ve never used this in play, so it’s all theoretical at this stage but it promises to be more accurate and realistic without being a huge amount of work.

Here’s how it’s supposed to work – overview only, I’ll go into more detail afterwards:

     1. GM sets the climate baselines (once per general location).
     2. GM determines the seasonal weather trends (once per general location).
     3. GM rolls for the daily temperature variation.
     4. GM rolls for the change in Weather Threshold Change.
     5. Apply change to long or short threshold, whichever is operative..
     6. GM rolls d6 and d20 for the daily humidity variation.
     7. GM determines the Trend.
     8. GM totals Trend + Rolled Adjustment for both temperature and humidity.
     9. GM compares both temperature and humidity to the change threshold.
     10. GM interprets the weather forecast, adding the baseline and seasonal weather trends to the temperature and humidity to get daily peak values..

Even this makes it sound a lot more complicated than I think it is.



Red Sky In The Morning, Sailor Take Warning….
Imageby Joe from Pixabay

4.8.7.4 Climate Baselines

A year is divided into 4 seasons, each of which is divided into 2 parts, giving 8 baseline slots in a year. These are used to describe the climate, which is used – as the name suggests – as a baseline for the system.

If you can identify a real-life location with similar weather, you may be able to get climate information about the specific location – Wikipedia is often very useful for this. But, if not, this section will show you how to do it from scratch with total imagination.

Weather at Sea is actually more predictable than weather over land, because there’s not as much to complicate and confuse it – it’s all empty ocean except along the coasts. The dominant factors are therefore general location (the Atlantic has different patterns to the Pacific) and latitude. Longitude only really comes into it if you are near a continental coastline – the one to the east will have a different impact to the one on the western side of the ocean.

I mentioned the differences between the Atlantic and Pacific – water temperature is a big part of that. The pacific is comparatively warm, the Atlantic comparatively cool, for reasons far too involved to get into here. The Med is generally warm, the North Sea not. Without looking it up, from latitude alone, I would expect the Black Sea to be fairly Mediterranean in climate.

Start with Midsummer – what’s the average temperature and what’s the average humidity?

Next, Midwinter – same questions.





Mid-Spring and Mid-Autumn are next, and where things can get interesting. Put a ruler down between the midsummer and midwinter points. You can either be on that line (a), above it (b), or below it (c) – you get to choose.

Next, we do the start of each season in exactly the same way, Draw a line connecting the points and hey presto! Job done!

I’ve done a blank chart that you can open in a new tab by clicking the thumbnail to the right. Because once you’ve done this once, you can use it again and again for that general location.



Here’s a fully worked example giving my perceptions of Sydney Weather after 40-odd years of living here.

     ★ Average Max Temp, Midsummer: 40 degrees Centigrade.

     ★ Average Daytime max, Midwinter: 18 degrees Centigrade.

     ★ Mid-autumn: Cooler than the average by a bit (nothing so extreme as the first example, which was deliberately exaggerated – a bit). 24°C.

     ★ Mid-spring: Both Spring and Winter seem to come early these days, and this is the turning point, so it’s right on the average between Midsummer and Midwinter.

     ★ Both Spring and Summer are a little warmer than the average, 24° and 32°, respectively.

     ★ The start of Autumn is even warmer at 36°C and the start of winter is noticeably cooler than the average at 20°C.

Note that it doesn’t matter whether you prefer °C, °F, or even Kelvins! You get to label the scale whatever you want (so long as your entire temperature range fits in the 40-division scale).

     ★ Humidity: typically fairly high in Sydney, midsummer peak of 40%, midwinter 24%, mid-spring and mid-autumn both way above the average of those two points at 36%.

     ★ Spring, also above the average of the points on either side of it at 33%; the start of summer is slightly down on the straight average, at 37%; the start of autumn is a very summery 39%; and the start of winter is well below the straight average at 26%.

4.8.7.5 Seasonal Weather Trends

Next, we need to count the differences and get a simple number for the change each N days, or the N days for a convenient rate of change. These are the seasonal weather trends.

     ★ Sydney Midsummer 40°C; Start of Autumn, 33°C; difference 7°C.

365 days in a year, / 8 = 45.625 days.

Always divide the bigger by the smaller. That will usually mean days / difference, but might not always do so when it comes to humidity or Fahrenheit temperature differences.

     ★ 45.625 / 7 = -1° every 6.5 days.

     ★ Start of autumn, 33°; mid-autumn, 24°; difference of 9°; 45.625 / 9 = -1° every 5 days.

One more:

     ★ Winter 20°; midwinter 18° – but just for the heck of it, let’s put both into Fahrenheit: 68°F to 64.4° (call it 64 1/2) – difference of 3.5°F. 45.625 / 3.5 = -1°F every 13 days.

But with a half-degree there, I’m tempted to take both of them to the half-degree mark.

To do this, I simply halve the time-span for a whole degree.

     ★ -1°F every 13 days becomes -0.5°F every 6.5 days.

Write these down on or below your weather chart. And leave a little room to write two more numbers underneath.

You don’t have to calculate them all right now, but you may as well.

Do the same thing for humidity and move on.

4.8.7.6 Long and Short Base Thresholds

The Long Threshold is how much buildup there has to be before there is a change in the weather.

Start by thinking about the length of the weather cycle – here in Sydney, it’s typically 7-and-a-bit days, at least in summer. If it rains Monday this week, it will probably rain on Monday next week, and the one after that – and then it will be Tuesday, and Tuesday again, and so on.

This pattern gets reset by the occasional more extreme weather event, but that’s the basic gist of it. And it means that the long threshold and short threshold will total 7-and-a-bit.

     ★ Maybe 7.3.

Important: For °F all thresholds should be doubled. This is because a °F is smaller than a °C, so you need more of them for the same change in weather. For high humidity locations, use the °F tables and double the threshold (for humidity) regardless of the temperature units being employed.

     ★ Again in midsummer, the typical short threshold is 1.5 days – sometimes it’s one day, sometimes 2, sometimes something in between.

     ★ 7.3 – 1.5 = 5.8. So that’s my base long threshold for midsummer and the 45.625 days that follow it.

     ★ In winter, the two are a lot closer. We’re still talking a 7-day cycle, but the short is more like 2.6 days (sometimes 2, occasionally 3 or 4), and the long is 7.5 – 2.6 = 4.9.

The higher the long threshold, the more stable and predictable the weather is. The longer the short threshold, the longer it takes to go back to that stable and predictable ‘normal weather’ after a disruption.

So go ahead and do all of these as well.

So, if I was using °F: the values I should use are cycle 14.6, long thresholds (summer) 11.6 and (winter) 9.8, short thresholds 3 (summer) and 5.2 (winter).

4.8.7.7 Daily Temperature Variation

With that prep out of the way, the system is now ready for use, believe it or not.

Let’s say that we’re doing a forecast for Sydney for 22 days into Autumn.

The relevant numbers from the chart, i.e. the work already done::

     ★ Autumn base temp = 33°C; Mid-autumn = 24°C; difference = 9; so -1 degree every 5 days.

     ★ 22 / 5 × -1 = -4.4°, so right now the long-tern average would be about 28.6°C.

     ★ Autumn base humidity = 39%; mid-autumn = 36%; difference = 3; so -1% every 15.2 days, or -0.5% every 7.6 days.

     ★ 22 / 7.6 × -0.5 = -1.447%, call it -1.4%, so the long term average is now about 37.6%.

     ★ Long Threshold: Midsummer + Midwinter = 5.8 + 4.9 = 10.7; average = 5.35.
     ★ Short Threshold: Midsummer + Midwinter = 1.5 + 2.6 = 4.1; average = 2.05.
     ★ But, given the season, long should be a little shorter and short a little longer. Use 5.2 and 2.5.


Roll a d6:
     1-2 = minus
     3-4 = same as yesterday
     5-6 = plus

But we don’t know what yesterday was, so if a 3 or 4 comes up, we may have to roll that, too. In fact, we may have to regress a number of days before a valid answer pops out.

The next part is a little trickier.

Roll a d6 for the adjustment column and a d20 for the adjustment amount on the table below:

	°C / Low Humidity
	d6	1	2	3	4	5	6
d20	1	0.1	0.2	0.3	0.4	<0.5	0.6
	2	0.2	0.3	0.5	0.6	0.7	0.8
	3	0.3	0.4	0.6	0.7	0.9	1
	4	0.4	0.5	0.7	0.8	1	1.2
	5	0.5	0.6	0.8	1	1.2	1.4
	6	0.6	0.7	0.9	1.1	1.3	1.5
	7	0.7	0.8	1	1.2	1.4	1.6
	8	0.8	0.9	1.1	1.3	1.5	1.7
	9	0.9	1	1.2	1.4	1.6	1.8
	10	1	1.1	1.3	1.5	1.7	1.9
	11	1.1	1.2	1.4	1.6	1.8	2
	12	1.2	1.3	1.5	1.7	1.9	2.1
	13	1.3	1.4	1.6	1.8	2	2.2
	14	1.4	1.5	1.7	1.9	2.1	2.3
	15	1.5	1.6	1.8	2	2.2	2.4
	16	1.6	1.7	1.9	2.2	2.3	2.5
	17	1.7	1.8	2	2.4	2.5	2.6
	18	1.8	1.9	2.2	2.5	2.6	2.7
	19	1.9	2	2.4	2.6	2.7	2.8
	20	2	2.2	2.5	2.7	2.8	3

 

	°F / High Humidity
	d6	1	2	3	4	5	6
d20	1	0.2	0.4	0.5	0.7	0.9	1.1
	2	0.4	0.5	0.9	1.1	1.3	1.4
	3	0.5	0.7	1.1	1.3	1.6	1.8
	4	0.7	0.9	1.3	1.4	1.8	2.2
	5	0.9	1.1	1.4	1.8	2.2	2.5
	6	1.1	1.3	1.6	2	2.3	2.7
	7	1.3	1.4	1.8	2.2	2.5	2.9
	8	1.4	1.6	2	2.3	2.7	3.1
	9	1.6	1.8	2.2	2.5	2.9	3.2
	10	1.8	2	2.3	2.7	3.1	3.4
	11	2	2.2	2.5	2.9	3.2	3.6
	12	2.2	2.3	2.7	3.1	3.4	3.8
	13	2.3	2.5	2.9	3.2	3.6	4
	14	2.5	2.7	3.1	3.4	3.8	4.1
	15	2.7	2.9	3.2	3.6	4	4.3
	16	2.9	3.1	3.4	4	4.1	4.5
	17	3.1	3.2	3.6	4.3	4.5	4.7
	18	3.2	3.4	4	4.5	4.7	4.9
	19	3.4	3.6	4.3	4.7	4.9	5
	20	3.6	4	4.5	4.9	5	5.4

NB>: Humidity cannot exceed 100%. Any excess: /10 and add to the conditions adjustment. That’s because humidity doesn’t drive changes in the weather in this system, temperature does.



I’ve put all 5 tables into a Free PDF for reader’s convenience. This includes the tables below for Threshold adjustment. NB: This includes a slightly older version of the above tables – the numbers are the same but some of the labels are incorrect.

Continuing the Sydney example:
     ★ d6 roll: 2 so “minus”.

     ★ d6 roll 4, d20 roll 14.
     ★ °C change = minus 1.9.

     ★ d6 roll 4, so “same as yesterday”
     ★ roll again for yesterday: 5 so “plus”

     ★ Yesterday’s change: d6 roll 6, d20 roll 10. % Humidity change = plus 1.9.
     ★ Today’s change: d6 roll 2, d20 roll 12. % humidity change today = plus 1.3.
     ★ 1.3 + 1.9 = 3.2. So, overall, the humidity is 3.2% higher than the average for this time of year.



…Red Sky At Night, Sailor’s Delight!
Well, it might not be 100% reliable, but it’s better than nothing!
Image by Jody Davis from Pixabay

4.8.7.8 Weather Change Threshold

Since we’re assumed to be starting a cycle (now in it’s second day because I had to re-roll once for ‘yesterday’) we’re adjusting the long threshold, which is usually the case.

Same as above except that the original d6 roll remains – it said “minus” so the threshold change is a minus.:

	°C / Low Humidity
	d6	1	2	3	4	5	6
d20	1	0.025	0.07	0.15	0.3	0.425	0.72
	2	0.05	0.105	0.25	0.45	0.595	0.96
	3	0.075	0.14	0.3	0.525	0.765	1.2
	4	0.1	0.175	0.35	0.6	0.85	1.44
	5	0.125	0.21	0.4	0.75	1.02	1.68
	6	0.15	0.245	0.45	0.825	1.105	1.8
	7	0.175	0.28	0.5	0.9	1.19	1.92
	8	0.2	0.315	0.55	0.975	1.275	2.04
	9	0.225	0.35	0.6	1.05	1.36	2.16
	10	0.25	0.385	0.65	1.125	1.445	2.28
	11	0.275	0.42	0.7	1.2	1.53	2.4
	12	0.3	0.455	0.75	1.275	1.615	2.52
	13	0.325	0.49	0.8	1.35	1.7	2.64
	14	0.35	0.525	0.85	1.425	1.785	2.76
	15	0.375	0.56	0.9	1.5	1.87	2.88
	16	0.4	0.595	0.95	1.65	1.955	3
	17	0.425	0.63	1	1.8	2.125	3.12
	18	0.45	0.665	1.1	1.875	2.21	3.24
	19	0.475	0.7	1.2	1.95	2.295	3.36
	20	0.5	0.77	1.25	2.025	2.38	3.6

 

	°F / High Humidity
	d6	1	2	3	4	5	6
d20	1	0	0.1	0.3	0.5	0.8	1.3
	2	0.1	0.2	0.5	0.8	1.1	1.7
	3	0.1	0.3	0.5	0.9	1.4	2.2
	4	0.2	0.3	0.6	1.1	1.5	2.6
	5	0.2	0.4	0.7	1.4	1.8	3
	6	0.3	0.4	0.8	1.5	2	3.2
	7	0.3	0.5	0.9	1.6	2.1	3.5
	8	0.4	0.6	1	1.8	2.3	3.7
	9	0.4	0.6	1.1	1.9	2.4	3.9
	10	0.5	0.7	1.2	2	2.6	4.1
	11	0.5	0.8	1.3	2.2	2.8	4.3
	12	0.5	0.8	1.4	2.3	2.9	4.5
	13	0.6	0.9	1.4	2.4	3.1	4.8
	14	0.6	0.9	1.5	2.6	3.2	5
	15	0.7	1	1.6	2.7	3.4	5.2
	16	0.7	1.1	1.7	3	3.5	5.4
	17	0.8	1.1	1.8	3.2	3.8	5.6
	18	0.8	1.2	2	3.4	4	5.8
	19	0.9	1.3	2.2	3.5	4.1	6
	20	0.9	1.4	2.3	3.6	4.3	6.5

Continuing the Sydney example:
     ★ d6 roll: still “minus”, as noted above.

     ★ d6 roll 3, d20 roll 2. Threshold change = minus 0.25.

4.8.7.9 Trend

“Trend” only impacts accumulated change, not threshold. It is equal to 1/2 of yesterday’s change if any was recorded, or 0 otherwise.

Continuing the Sydney example:
No change was documented yesterday for temperature, which is what drives changes in the weather, so the trend is 0 at the moment.

4.8.7.10 Result Totals:

This is easier demonstrated than explained, so Continuing the Sydney example:

     ★ Temperature: Time-of-year average 28.6°C minus 1.9 = 26.7°C.
     ★ Humidity: Time-of-year average 37.6% plus 1.9 (yesterday) plus 1.3 (today) = 40.8%.
     ★ Change: Trend 0 em>plus 1.9 = 1.9
     ★ Long Threshold = 5.2 minus 0.25 = 4.95.
     ★ Short Threshold = 2.5, unchanged because it is not the active threshold at the moment.
     ★ Is the Change greater than the operative threshold? 1.9 is not greater than 4.95. Therefore, no change in the weather.

Write these down, and save yourself a bit of time by calculating the Trend for tomorrow while you’re about it:

     ★ Tomorrow’s Trend = -1.9 / 2 = -0.95

It should be recognized that the time-of-year correction and the Trend are both deliberate biases built into the system. One tracks with the flow of she seasons and is in the direction that seasonal averages would expect; the other tracks with previous changes so that they can accumulate until a change in the weather is triggered..

4.8.7.11 Interpretation




If the sea looks like this, I would interpret it to mean we’re in trouble! Image of the Naruta Whirlpools taken from a boat that cruises directly to them by Hellbuny and used under the Creative Commons Attribution-Share Alike 3.0 Unported license, courtesy Wikimedia Commons

How these factors come together into a weather report / forecast is up to the GM, but generally follows logic.

Take the Sydney example: temperature dropping (but still high), humidity rising (but still relatively low) – what can account for that? There are only two things: cloud cover and winds.

Well, winds are a whole separate deal, given how important they are to a sailing ship. But it’s fair to say that if they aren’t enough to justify that drop in temperature, the only remaining option is cloud cover. This could be partial, broken clouds, or it could be threatening rain – except that we’re nowhere near the threshold, and the humidity isn’t really high enough, so it’s more likely to be the first than the second.

4.8.7.12 Severity

A further tool at your disposal is the change total itself – this can be looked at as the fraction of a cycle or as the intensity of the change. They are both the same thing in this context.

     ★ 1.9 / 7.3 is a bit under two sevenths. Maybe three fourteenths. That says that the weather on this particular day is going to be appreciably mild – strong winds being a possible exception, but they aren’t very likely.

     ★ Today’s forecast: Warm with broken cloud and light winds. There is a remote chance of a brief thunderstorm in the later afternoon which will have no significant weather consequences. Similar conditions are likely to persist for several days to come.

4.8.7.12.1 Extending The Example

Just to show readers how it works, and because it provides a lead-in to the next sections, let’s extend that forecast for a while.

Day 2:

     ★ Time-of-year average Temperature: 28.6°C – (1 / 5) = 28.6 – 0.2 = 28.4.
     ★ Time-of-year average Humidity: 37.6% – (0.5 / 7.6) = 37.6 – 0.066 = 37.6 – 0.07 = 37.53%.

     ★ Change Direction Temperature (d6): 1, so minus.
     ★ Change rolled (d6, d20) = (2, 9) = 1 degree.
     ★ Change Direction Humidity (d6): 5, so plus.
     ★ Change rolled (d6, d20) – (4, 6) = 1.1%

     ★ Temperature: Time-of-year average 28.4°C minus 1 = 27.4°C (actually slightly warmer).
     ★ Humidity: Time-of-year average 37.53% plus 1.1 = 38.63%.
     ★ Change: Trend 0.95 + Change 1.9 (yesterday) + 1 (today)= 3.85.

     ★ Threshold Change Direction (d6): 6, so plus for the first time
     ★ Threshold Change Rolled (d6, d20) = (4, 14) = 1.42
     ★ Long Threshold = 4.67 plus 1.42 = 6.09.
     ★ Short Threshold = 2.5, unchanged
     ★ Is the Change greater than the operative threshold? 3.85 is not greater than 6.09. Therefore, no change in the weather.

     ★ Tomorrow’s Trend = 3.85 / 2 = 1.925, round to 1.93.

Interpretation: Slightly warmer but with increasing cloud cover. Light winds.

Day 3:

     ★ Time-of-year average Temperature: 28.4°C – (1 / 5) = 28.4 – 0.2 = 28.2.
     ★ Time-of-year average Humidity: 37.53% – (0.5 / 7.6) = 37.6 – 0.066 = 37.6 – 0.07 = 37.46%.

     ★ Change Direction Temperature (d6): 2, so minus.
     ★ Change rolled (d6, d20) = (5, 8) = 1.5 degrees.
     ★ Change Direction Humidity (d6): 5, so plus.
     ★ Change rolled (d6, d20) – (1, 18) = 1.8%

     ★ Temperature: Time-of-year average 28.2°C minus 1.5 = 26.7°C
     ★ Humidity: Time-of-year average 37.46% plus 1.8 = 39.26%.
     ★ Change: Trend 1.93 + Change 1.5 + 3.85 (previous change) = 6.28

     ★ Threshold Change Direction (d6): 1, so minus
     ★ Threshold Change Rolled (d6, d20) = (6, 16) = 0.28
     ★ Long Threshold = 6.09 minus 0.28 = 5.81.
     ★ Short Threshold = 2.5, unchanged
     ★ Is the Change greater than the operative threshold? 6.28 is greater than 6.09. The weather changes – from sunny to rain.

     ★ Tomorrow’s Trend = 0 because the weather has turned.

Interpretation: Cloudy & cooler, showers becoming likely in the evening.

Day 4:

     ★ Time-of-year average Temperature: 28.2°C – 0.2 = 28.0.
     ★ Time-of-year average Humidity: 37.46% – 0.07 = 37.39%.

     ★ Change Direction Temperature (d6): 5, so plus.
     ★ Change rolled (d6, d20) = (6, 12) = 2.1 degrees.
     ★ Change Direction Humidity (d6): 6, so plus.
     ★ Change rolled (d6, d20) – (2, 5) = 0.6%

     ★ Temperature: Time-of-year average 28.0°C plus 2.1 = 30.1°C
     ★ Humidity: Time-of-year average 37.39% plus 0.6 = 39.86%.
     ★ Change: Trend 0 + Change 2.1= 2.1

     ★ Threshold Change Direction (d6): 2, so minus
     ★ Threshold Change Rolled (d6, d20) = (2, 17) = 0.63
     ★ Long Threshold resets to base value of 5.2
     ★ Short Threshold = 2.5 minus 0.63 = 1.87
     ★ Is the Change greater than the operative threshold? 2.1 is greater than 1.87. The weather changes – from rain to sunny.

     ★ Tomorrow’s Trend = 0 because the weather has turned again.

Interpretation: Very warm, showers clearing.

Before I can continue with the example, I need to explain how rain affects humidity.

4.8.7.13 Clouds & Rain

If humidity goes over 70%, cloud cover is pretty close to inevitable. The daily base weather changes to include this without the weather pattern itself changing (unless the threshold for such a change is exceeded).

Rain events can be savage downpours or constant precipitation or a thunderous deluge or a continuous drizzle or passing showers.

     ★ Calculate the difference between 4 x the humidity before the event and half the time of year average for the day.

     ★ Divide by the number of days that this event is going to last, as determined in previous sections.

     ★ Roll a d8 and consult the tables below (these have also been included in the free PDF):

Precipitation Event Type
Humidity Ratio		d8
		1	2	3	4	5	6	7	8
<0	25	1	1	1	1	1	2	2	3
26	50	1	1	1	1	2	2	3	3
51	75	1	1	2	2	2	3	3	3
76	100	1	2	2	2	3	3	3	4
101	125	2	2	3	3	3	4	4	5
> 125		3	3	3	4	4	4	5	5

 

Precipitation Event Type		Description (and alternative)							Daily Loss
1		One or more light showers, passing				Snow Flurry			33%
2		Continuous Drizzle for multiple hours				Snow			40%
3		One or more (brief) thunderstorms				Snow &/or Hail			50%
4		Constant, steady, soaking rain				Heavy Snow or Sleet			60%
5		Massive Downpour lasting 1-3 hours				Blizzard			75%

EG1: Base 40% humidity, currently 30%, Duration 1 day

     ★ 4 × 30 – (40 / 2) = 120-20=100; 100 / 1 = 100
     ★ d8 roll = 5
     ★ Type 3 weather event
     ★ one or more thunderstorms, snow & possible hail if cold enough

EG2: Base 25% humidity currently 35%, Duration 2 days

     ★ 4 × 35 – (25/2) = 140 – 12.5 = 127.5 / 2 = 63.75
     ★ d8 roll = 4
     ★ Type 2 weather event
     ★ Continuous Drizzle or Snow for several hours

EG3: Base 25% humidity, currently 45%, Duration 2 days

     ★ 4 × 45 – (25 / 2) = 180 – 12.5 = 167.5; 167.5 / 2 = 83.75
     ★ d8 roll = 8
     ★ Type 4 weather event
     ★ Constant soaking rain or heavy snow (possible sleet) if cold enough

EG 4: Base 25% humidity, currently 45%, Duration 3 days

     ★ 4 × 45 – (25 / 2) = 180 – 12.5 = 167.5; 167.5 / 2 = 55.8
     ★ d8 roll = 8
     ★ Type 3 weather event again
     ★ As above

EG5: Base 25% humidity, currently 45%, Duration 1 day

     ★ 4 × 45 – (25 / 2) = 180 – 12.5 = 167.5; 167.5 / 1 = 167.5
     ★ d8 roll = 8
     ★ Type 5 weather event
     ★ Massive downpour lasting 1-3 hours

EG6: Base 40% humidity, currently 55%, Duration 4 days

     ★ 4 × 55 – (40/2) = 220-20 = 200; 200/4 = 50
     ★ die roll = 3
     ★ Type 1 weather event
     ★ One or more light showers each day, passing

EG7: Base 40% humidity, currently 55%, Duration 2 days

     ★ 4 × 55 – (40/2) = 220-20 = 200; 200/2 = 100
     ★ die roll = 3
     ★ Type 2 weather event
     ★ Continuous Drizzle most of the day

On the table, note the “Daily Loss”. That’s how much of the current humidity gets lost in the course of 1 day of this weather event.

If this takes the total below the Base for this time of year, all humidity adjustments are +5%/day until this is no longer true. Long Thresholds increase by 2 while this is taking place.

Let’s look at those 7 examples again:

EG1: 1-day Type 3 event starting at 30% humidity vs a Base of 40%:

     ★ 50% daily loss
     ★ 50% of 30% is 15%
     ★ Humidity after event = 30 – 15 = 15%
     ★ 15% is less than 40% so +5%/day for next 5 days, maybe more.

EG2: 2-day Type 2 event starting at 35% vs a base of 25%

     ★ 40% daily loss
     ★ 40% of 35% is 14%
     ★ Humidity after event = 35 – 14 = 21% after day 1
     ★ 40% of 21% is 8.4%
     ★ Humidity after event = 21 – 8.4 = 12.6% after day 2
     ★ 12.6% is less than 25% so +5%/day for next 3 days or so.

EG3: 2-day Type 4 event starting at 45% vs a base of 25%

     ★ 60% daily loss
     ★ 60% of 45% is 27%
     ★ Humidity after event = 45 – 27 = 18% after day 1
     ★ 60% of 18% is 10.8%
     ★ Humidity after event = 18 – 10.8 = 7.2% after day 2
     ★ 7.2% is less than 25% so +5%/day for next 4-5 days.

EG4: 3-day Type 3 event starting at 45% vs a base of 25%

     ★ 60% daily loss
     ★ 60% of 45% is 27%
     ★ Humidity after event = 45 – 27 = 18% after day 1
     ★ 60% of 18% is 10.8%
     ★ Humidity after event = 18 – 10.8 = 7.2% after day 2
     ★ 60% of 7.2% is 4.32%, round to 4.3%
     ★ Humidity after event = 7.2 – 4.3 = 2.9% after day 3
     ★ 2.9% is less than 25% so +5%/day for next 5-6 days.

EG5: 1-day Type 5 event starting at 45% humidity vs a Base of 25%:

     ★ 75% daily loss
     ★ 75% of 45% is 33.75%, round to 33.8
     ★ Humidity after event = 45 – 33.8 = 11.2%
     ★ 11.2% is less than 25% so +5%/day for next 3 days or so.

EG6: 4-day Type 1 event starting at 55% humidity vs a Base of 40%

     ★ 33% daily loss
     ★ 33% of 55% is 18.3%
     ★ Humidity after event = 55 – 18.3 = 36.7% after day 1
     ★ 33% of 36.7% is 12.2%
     ★ Humidity after event = 36.7 – 12.2 = 24.5% after day 2
     ★ 33% of 24.5% is 8.167%, round to 8.2%
     ★ Humidity after event = 24.5 – 8.2 = 16.3% after day 3
     ★ 33% of 16.3% is 5.433%, round to 5.4%
     ★ Humidity after event = 16.3 – 5.4 = 10.9% after day 4
     ★ 10.9% is less than 40% so +5%/day for next 6 days, give-or-take.

EG7: 2-day Type 2 event starting a 55% humidity vs a base of 40%

     ★ 40% daily loss
     ★ 40% of 55% is 22%
     ★ Humidity after event = 55 – 22 = 33% after day 1
     ★ 40% of 33% is 13.2%
     ★ Humidity after event = 33 – 13.2 = 19.8% after day 2
     ★ 19.8% is less than 40% so +5%/day for approximately the next 5 days.

Tropics add 2 to the Event Type in the rainy season and +10% per day recovered.

4.8.7.14 Winds

Given that we’re talking about sailing ships, winds are pretty close to all-important. For that reason, I’ve gone more deeply into the subject than I otherwise would have.

4.8.7.14.1 Wind Speed

This is based on a divided die roll. These are useful because they permit extreme but improbable results while maintaining a low that is bunched up toward the low end of the results.

     ★ Step 1: 5d10 =
     ★ Step 2: + 1/2 × d% =
     ★ Step 3: × 4.84 / 4d6, round down =
     ★ Step 4: + 2d6

This has a minimum of 0, an average of 22.5, and a maximum of 133. The lowest result with a significant chance of occurring is 11 (0.58%) and the highest is 44 (0.51%). So it’s far to say the result is usually 11-44, with 22-23 the most likely, but with a slim chance of results outside of this.

I’ve done a graph using AnyDice, my favorite tool for this sort of thing, and am presenting it below in two ways. First, the usual orientation of these things:



And now, turned on it’s side (so that I can make it far bigger):



These show the two constituents. Note the way the “+2d6” smooths the probability curve out!

The results are significant. Once again: Usually 11-44, with 22-23 the most likely, but with a slim chance of results outside of this, down to 0 or up to 133:

Beaufort Scale Table 1
km/h		mph		knots		ft/sec		m/sec		Beaufort Number
low	high	low	high	low	high	low	high	low	high
0	0	0	0	0	0	0	0	0	0	0
2	5	1	3	1	3	1	4	0.4	1.3	1
6	11	4	7	3	6	6	10	1.8	3.1	2
13	19	8	12	7	10	12	18	3.6	5.4	3
21	29	13	18	11	16	19	26	5.8	8	4
31	39	19	24	17	21	28	35	8.5	10.7	5
40	50	25	31	22	27	37	45	11.2	13.9	6
51	61	32	38	28	33	47	56	14.3	17	7
63	74	39	46	34	40	57	67	17.4	20.6	8
76	87	47	54	41	47	69	79	21	24.1	9
89	101	55	63	48	55	81	92	24.6	28.2	10
103	121	64	75	56	65	94	110	28.6	33.5	11
122+		76+		66+		111+		34+		12

…they can be used directly on the km/h column.

Conversions: 100 km/h = 62.1371 mph = 53.9957 knots = 27.7778 m/s = 91.1344 f/s

but, it’s usually close enough to say:

100 km/h = 62 mph = 54 knots = 28 m/s = 91 f/s

Okay, so what does the “Beaufort Number” mean, in real terms? I’ve more or less covered this before, but we’re talking events at sea, and that requires additional information.



Ship on Stormy Seas by Ivan Aivazovsky, Public Domain, courtesy Wikimedia Commons

Beaufort Scale Table 2
Beaufort Number	Unofficial Label	Description
0	Calm	No Wind, Sea is like a mirror. Sails useless.
1	Light Air	Barely moves tree leaves. Water ripples but no foam crests. Waves under 0.5 ft.
2	Light Breeze	Wind felt, leaves & weather-vanes Move. Small wavelets with glassy tops crests that do not break, 0.5-1 foot height. Light flags fully extended. Insufficient wind for anything larger than a Sloop.
3	Gentle Breeze	Leaves in constant motion, Wavelets 2-3 ft in height, crests begin to break, foam of glassy appearance, occasional whitecap.
4	Moderate Winds	Small Branches move, dust and light objects blown about. No noticeable sound from the rigging. Flags extended, heavy flags flap limply. Waves 3-5 ft high, frequent whitecaps. Slack halyards curve and sway.
5	Fresh Winds	Wind felt strongly. Large Branches & small trees sway, Crested wavelets on inland lakes & rivers. Waves tending to be long 6-8 ft tall at sea, some spray. Slack halyards whip while bending continuously to leeward, taut ones maintain slightly bent positions. Heavy flags do not extend but flap over entire length.
6	Strong Winds	Large Branches in continuous motion, Umbrellas used with difficulty. Large Waves 9-12 ft in height begin to form, some spray likely, white caps extensive. Below 35°F (22°C), wind stings face. Slight effort to maintain balance against the wind. All halyards whip slightly. Low moaning from the rigging. Heavy flags extend fully and flap more vigorously.
7	Dangerous Winds	Whole trees in motion, hard to walk Against the wind and you have to lean into the wind to stand up. Waves 13-19 ft, white foam from breaking waves begins to be blown in streaks along direction of wind. Low whistling from rigging. Oilskins & loose clothing catch the wind and puff out. Heavy flags fully extended and only flap at the ends.
8	Gale	Wind breaks twigs & small branches, and impedes walking. At sea, creates waves 18-25 ft tall. The edges of crests begins to break, blown in clear streaks following the line of wind. Loose clothing blows out strongly, loose limbs/head blown back if resistance is relaxed. Loud whistle from the rigging, Heavy flag flies straight out fully extended. Masts noticeably bend and creak and sail must be reduced to 50%.
9	Strong Gale	Structural damage to buildings, tree branches downed. Waves 23-32 ft with dense streaks along direction of wind. Crests of waves begin to topple. tumble, and roll over. Spray may affect visibility. Sails must be reduced to 25% or less and masts are still at risk. Wind cannot be safely quartered without risk of capsizing.
10	Extreme Gale	Considerable structural damage, weak roofs torn apart, small trees uprooted. Large tree limbs may break. Glass windows may shatter from wind alone. Waves 29-41 ft high with long overhanging crests. Foam in great patches is blown in dense patches in the line of the wind. Sea is overall whitish from foam and tumbling becomes heavy. Visibility down to approx 15-25m. Sails must be taken/cut down or masts will break. Wooden vessels can be felt flexing underfoot, must be anchored or will be turned sideways and then capsized. Anchor chains taught and may break Impossible to walk into the wind without ropes or similar assistance.
11	Weak Hurricane	Widespread damage, roofs may be completely torn away and large trees uprooted. Masts break even without sails. Waves 37-52 ft tall, small & medium ships completely lost to view behind waves. Sea completely covered with long patches of foam along the direction of the wind. Edges of wave crests are blown into froth. Visibility of 5-15m. Anchor chains at risk, ships assume extreme angles, turning to broadside the wind; chains may have to be cut / released. Impossible to stay upright in the wind and even crawling is difficult.
12	Hurricane	Severe and extensive damage, Vehicles overturned, timber houses leveled. The air at sea is filled with foam and spray. The sea is completely white. Visibility is 2-5m only. Cannot crawl into the wind. Small buildings may be leveled or torn away whole. Anchor chains snap, ships capsize unless steered directly away from or into the wind and most can’t respond to slight variations in wind direction quickly enough. Masts lost / broken, and it is often safer to chop them down. Ships may break in two. People are lifted up / blown away.

We’re not quite done yet – there are a couple of biases to throw in.

Step 5: If there is a significant change in temperature, add 4.
Step 6a: If there is an actual change in conditions, add 2d6+5 when moving to short threshold; or
Step 6b: divide by 2 and add 2d6+5 if moving to or in long threshold.
Step 7: (optional): divide by 2 and add half of yesterday’s result.

Personally, I wouldn’t go with the Step 7 option; one day doesn’t have to look like another and there’s enough variability built into the system that it’s probably a wasted effort, anyway.

EG1: 2.5° drop in temp, long threshold conditions. Yesterday’s wind at this time of day was 26 km/h..

     ★ 5d10 roll = 25
     ★ + 1/2 d% roll = +46 / 2 = +23; total 48
     ★ x 4.84 / 4d6 = × 4.84 / 7 = 33
     ★ + 2d6 roll = +9, total 42.
     ★ 42 is Beaufort Scale 6, strong winds.

Commentary: because the 4d6 roll was well below average, the result is right at the top of the results spread that should be expected, most of the time. If the 5d10 had been higher, the wind speed would be well outside the normal range.

     ★ 2.5°C is not a huge temp drop, but it is noteworthy. The GM rules it significant.
     ★ 42 + 4 = 46.
     ★ Step 6a does not apply.
     ★ Divide by 2 = 23
     ★ add 2d6++5 rolled =+8 = 31.

     ★ 31 is right at the bottom limit of Beaufort Scale 5, Fresh Winds.

Steps 5 and 6 definitely make a difference.

     ★ Optional: 31/2 = 15.5; + 1/2 of 26 = +13, total 28.5.
Commentary This would be enough to drop to Beaufort Scale 4, Moderate Winds – for no better reason than there were Moderate Winds yesterday, too. I don’t think shifting from one Beaufort Number to one higher is too big a step for a day. But it does make changes more gradual and progressive, less abrupt.

I could even see GMs deciding that Step 7 applies in some specific waters and not others. The Mediterranean is fairly sheltered by land; step 7 might apply. The Atlantic is notoriously more changeable than the Pacific; step 7 might also apply to the latter. Heck, there’s nothing stopping anyone who wants to from working out what the impact of Step 7 will be on any particular day and then deciding whether or not it’s in effect!

EG2: 1.2°C temperature change, weather becoming unsettled; yesterday at this time was 15 km/h.

     ★ 5d10 roll = 29
     ★ + 1/2 d% roll = +53 / 2 = +26.5; total 55.5
     ★ x 4.84 / 4d6 = × 4.84 / 23 = 11.68, round to 11.
     ★ + 2d6 roll = +7, total 18.
     ★ 1.2°C is a significant change.
     ★ Step 6a: +2d6+5 = +14; total 32.
     ★ Step 6b does not apply.
     ★ 32 is Beaufort Scale 5, Fresh Winds.

If ever there was a time to ignore Step 7, it’s when the weather changes.

One more: EG3: 2.5° Temperature Change, weather already unsettled becoming stable, yesterday at this time =28 km/h.

     ★ 5d10 roll = 30
     ★ + 1/2 d% roll = +72 / 2 = +36; total 66
     ★ x 4.84 / 4d6 = × 4.84 / 16 = 19.965, round to 19.
     ★ + 2d6 roll = +5, total 24.
     ★ 2.5°C is a significant change, so +4 = 28.
     ★ Step 6a: +2d6+5 = +7; total 35.
     ★ Step 6b: / 2 = 17.5, + d6+5 again = +7 (as already rolled) = 24.5.
     ★ 24 is Beaufort Scale 4, Moderate Winds.

I’ve added a worksheet for these calculations to the free PDF. It has room for 9 calculations on a page (I wanted 10 but couldn’t quite fit them in).

4.8.7.14.2 Ship Speed vs Wind Speed

The trigonometry is fairly obvious – the speed of the ship is the amount of wind that is pushing the ship forward. By changing the angle of the ship relative to the wind, you can change the proportion of the wind that’s pushing you in the forward direction.

That’s far too complicated for a game. So, instead, I’ve employed the concept of Favorable Winds. I’ll go into this in much more detail in 4.8.7.14.5 below, but, in a nutshell:

Wind from directly behind is 70% efficient. Every ship has a defined angle of Favorable Winds – the base angle is ± 30° to either side.

Beyond that is a ‘near favorable’ wind, usually another 30° arc. Winds from this direction are 50% efficient.

After that comes ‘tolerable wind’, usually another 30° arc. Winds from this direction are 30% efficient.

‘Intolerable wind’ is blowing in completely the wrong direction. Some vessel types can nevertheless make forward progress at 10% efficiency. The rest need to rely on rowers.

Adding extra masts adds 5% efficiency to favorable winds, 7.5% to near-favorable and 3% to tolerable wind efficiencies. Extra masts also increase the ranges of Favorable Winds and Tolerable Winds by 10° for the first and 5° each after that. Note that all this is a simplification of a much more complex situation, and generalized, and even a bit exaggerated.

If the resulting speed is greater than the vessel’s limit, there is a risk of the wind uprooting the masts, which could break a ship in two. Find/estimate the % over maximum and add 35 – that’s the percentage chance per 30 minutes of this happening. If the % is over 100, halve both the % and the time scale between checks. Round % up and time down.

EG: 260% of safe speed: 35+260=295% every 30 minutes; becomes 147.5% every 15 minutes, becomes 73.75% every 7.5 minutes, becomes 74% every 7 minutes.

To avoid this, it is normal practice to ‘trim the sails’ until the speed is the maximum safe plus whatever margin the captain wants (just in case of a gust of greater force).

Another way to look at all this: divide the ship’s maximum rates speed by the % shown and you will find out at what wind speed you need to start trimming sail for safety.



Wind-driven waves like this can hide dangerous rocks even as they push a vessel toward them. Image credit: A stormy sea at Yellow Craig by Walter Baxte, available under the Creative Commons Attribution-Share Alike 2.0 Generic license.

4.8.7.14.3 Wind Direction

There are two ways of specifying wind direction: Wind From and Wind To. And endless confusion awaits unless you are clear which one you are talking about. Unless stated otherwise, or obviously otherwise (as in Favored Winds), I will consistently try to use Wind To.

Clearly, wind direction is just as important as wind speed. The base direction is always away from (day) or towards (night) the nearest significant land mass.

The GM decides what’s a significant land mass, and what’s not, but in general, peninsulas and small islands won’t cut it. A small island with a 10,000 foot mountain, on the other hand…



I threw the above image together to illustrate this point. Essentially, I put a whole heap of possible locations on the map and then guesstimated by eye where the closest land would be. There’s even one rogue point (bottom row, third from the right) that in retrospect should probably be a little more westerly, like those on either side of it.

There’s actually a lot to unpack in the image. The coast curves southwest from the start of the peninsula. This has a significant effect if you are trying to head north. From just below the point of the peninsula, the indicated nearest land-mass is north of most positions until you get to the right-hand side of the map – where the headlands between beaches bulge outward, causing more westerly deviations. That headland would be a great place for a trading port, with the beaches to either side for wharves.

A brief mention of scale: the map doesn’t have one. All that can be said is that there is no comparable landmass closer than the one shown. If that means that the map is 100 km to a side, or 1000, it doesn’t matter.

Significant (there’s that word again) levels of overgrowth can reduce the significance of the landmass. This is all about how hot the ground gets.

More than 50% cloud cover can also impact significance.

If there are no significant land masses in reasonable proximity, then the base direction is directly away from the equator and opposing the direction of motion of the planetary body. The closer to either equator or poles you are, the less significant the equatorial contribution and the more significant the rotational contribution:



But even this is sporting more precision than we really want. N,NE, E, SE, S, SW, W, NW – those eight directions are almost good enough. Throw in one more subdivision – NNW, etc – and we’re good to go. This divides the circle into 16 pieces of 22.5° each. That’s convenient, too, because the tropics are almost exactly 22.5° from the equator (the correct figure is 23.5°, but this is close enough).

Next, we have the familiar d6 roll:

d6
     1-2 minus angle (counterclockwise)
     3-4 as yesterday
     5-6 plus angle (clockwise)

And then a d20 (included in the Free PDF):

d20	Interpretation
1-6	0 steps from base direction
7-11	1 step from base direction
12-14	2 steps from base direction
15-16	3 steps from base direction
17-18	4 steps from base direction
19	5 steps from base direction
20	6 steps from base direction

There are two adjustments to the resulting direction:

     +1 step away from next greatest heat source
     +1 step towards west (if normal planetary rotation).

…. and that’s it. The hardest part is visualizing the environment and determining the base wind direction.

I realize that almost everyone will be completely familiar with it, but on the off chance that someone is not:



I had some room left, so I threw in figure 2 (actually, it ended up taking 4x as long as figure 1 to complete, but it seemed like a good idea at the time). This illustrates the probability of wind coming from a given direction relative to the base direction.

If the wind has a base direction from the Southwest, i.e, to the Northeast, then almost all of the time it will be 1-2 steps away at most, i.e. blowing to the North, North-North East, North-East, East-Northeast, or East. 70% of the time, one of those directions will be the wind direction, and 57% of the time it will NOT be the indicated Northeast, but off to one side or the other – but that’s before the adjustments above are taken into account.



This is what can easily result: A Shipwreck In Stormy Seas by Claude-Joseph Vernet, Public Domain, courtesy Wikimedia Commons

4.8.7.14.4 Wind Duration

Another critical question is how long the wind will blow before it shifts. Note that the strength usually doesn’t change from such a wind shift, it will stay steady – unless you are in short threshold mode.

This is a straight d% roll. As usual, also in the PDF.

d%	Wind Duration			d%	Wind Duration
01-06	(6%)	1 hour		75-84	(10%)	8 hours
07-14	(8%)	2 hours		85-87	(3%)	9 hours
15-26	(12%)	3 hours		88-93	(6%)	10 hours
27-40	(14%)	4 hours		94-95	(2%)	11 hours
41-54	(14%)	5 hours		96-99	(4%)	12 hours
55-66	(12%)	6 hours		0 0	(1%)	12 hours + roll again
67-74	(8%)	7 hours		Odd Numbers:		– 1/2 hour

     ★ The first Wind event of the day has a rolled duration threshold. It generally starts at around 4AM.

     ★ The second wind event lasts from the end of the first until 4 PM or for a new duration roll, whichever is later.

     ★ The third starts at 4PM+ and has a rolled duration.

     ★ The 4th starts at the end of the third and has a rolled duration or until 4AM, whichever is sooner.

     ★ The 5th event, if any, lasts until 4AM.

Let’s do an example or two.

EG1:
     ▪ Wind 1: 25 km/h North. d% roll = 74. Rolled duration 7 hrs. Starts approx 4AM, lasts until approx 11AM.

     ▪ Wind 2: still 25 km/h, now to the North-north-west. d% roll = 58, duration = 6 hrs i.e. to 5PM. This is later than the 4PM cutoff but it still applies.

     ▪ Wind 3: base direction has changed from NNW to SSE. Wind is 18 km/h and to the South. d% roll = 96. Duration = 11 hours. Starts at 5PM so that’s until 3AM.

     ▪ Wind 4: At 3AM, there is a wind shift to the ESE. Wind remains 18 km/h. It doesn’t matter what the d% roll is because at 4AM it will be the start of a new day with a new wind roll – according to the RAW.

       But if I were the DM, I’d rule that the day started an hour early (in terms of wind), just as the night started an hour late, and roll a duration starting from 3AM: d% = 49. Duration 5 hours, less 1/2 hour for the odd number result. Starting at 3 AM so lasting until 7:30 AM. And I would list this as Wind 1 of the next day.

EG2:
     ▪ Wind 1: 11 km/h ESE. Started at 4AM. d% roll = 77, duration 7.5 hrs, until 11:30 AM.

     ▪ Wind 2: still 11 km/h, shifted clockwise 0 steps relative to the adjusted base direction (East) – so wind shifts to the East. d% roll 40, duration of 4 hrs, from 11:30 AM to 3:30 PM.

     ▪ Wind 3:
still 11 km/h, shifted clockwise 5 steps from the base – so a big shift to the SSW! d% roll = 16, so Duration is 3 hrs, from 3:30PM to 6:30 PM. This is past the 4 PM wind change, which is delayed accordingly.

     ▪ Wind 4:
31 km/h. Baseline shifts from East to West. Wind direction is 2 steps counter-clockwise of that, to the Southwest. In effect, this is a 1-step change in wind direction. d% roll =53, so duration is 4 1/2 hrs from 6:30 PM to 11 PM.

     ▪ Wind 5: From 11 PM until 4AM, when the next baseline shift takes place, the wind is from the South, i.e. at right angles to what would normally be expected. It continues to be pretty strong at 31 km/h – officially “Fresh”. This is fast enough to cause considerable windchill, but that’s a subject for another day.

4.8.7.14.5 Favorable Winds

Favorable Winds are winds that move a vessel in the direction it wants to go. They don’t have to be perfect; just good enough for the sails to function properly.



Above are 5 panels. The first one illustrates what was described earlier – the favorability of the wind and the impact of extra masts on those values.

Once you get into the red / dark colors, you are (at least in part) trying to sail into the wind. That… doesn’t really work (see 4.8.7.14.7 unfavorable winds, below).

Again, the ratings are:
     Favorable 30°+ (70%+)
     Near Favorable 30°+ (50%+)
     Tolerable 30°+ (30%+)
     Intolerable 90°- (0 or 10%).

Extra Masts (each):
     +5% Favorable efficiency
     +7.5% Near-favorable
     +3% Tolerable efficiency

     +10° Favorable (to either side), first additional mast
     +5° Favorable (to either side), other additional masts
     +0° Near-favorable
     +10° Tolerable (to either side), first additional mast
     +5° Tolerable (to either side), other additional masts

The figure depicts a two-masted ship, so let’s work some numbers:
     ▪ Favorable: 70%+5% = 75% efficiency, Arc 30°+10°=40° to either side.
     ▪ Near Favorable: from 40° to 70° on either side, efficiency 57.5%
     ▪ Tolerable: 30+10=40° arc from 70° to 110° on either side; efficiency 30%+3%=33%.
     ▪ Intolerable: forward 70° to either side.

Here’s a quick comparison between 1 and 2 masts, showing exactly how much a vessel gains:



Here’s the fun part: Our wind direction system uses increments of 22.5° – or, more accurately, ±11.25°. The ship operations subsystem does not – people might consider that an oversight, or a mistake. This paragraph is here to correct any such impression – this is a deliberate choice because it makes the results a bit rubbery and flexible. The GM decides where in that ±11.25° the wind is actually blowing – and hence, at times, how favorable the winds are.

Some things are covered automatically – 22.5° to either side is less than 30°, but 33.75° is not – but unless the GM is deliberately nasty, players would reasonably expect both winds from directly behind the ship and any from one step to either side to be “Favorable”. It’s when winds stop being Favorable that this flexibility comes into its’ own.

Getting back to the main illustration, panel 2 shows a ship attempting to reach a port along line A1. The problem is that – as shown by line B1 – the closest significant land is West of the ship, and not in the desired direction of travel. And that means that the base winds are from the direction arcs shown.

Now, with 2 masts, there’s a 50-50 chance that these will still be at least Tolerable, and possibly even Near-Favorable, though that’s unlikely. So progress would be slow, but possible.

But time is money, and there is a faster approach. Note the dashed line – that’s the dividing line between the land to the North being the nearest significant landmass, and the land to the West. If the captain knows what he’s doing, he will try to position his vessel on the right-hand side of that dashed line, as shown in the third panel.

A2 is a shorter distance to land than B2, so the base winds are now oriented north and south. During the daytime winds, no progress might be possible, but when the wind shifts in the later afternoon, the captain can ride them all the way into harbor.

But time is money, and a smart captain will realize the situation shown in panel 4, in which the zone of maximum efficiency of his particular vessel has been mapped onto the harbor entrance, creating a zone between that and the dashed line. So long as he ends up anywhere in that zone when the winds shift, he can reasonably expect them to be favorable.

Panel 5 shows the results of what can be done by a captain who is smart enough – even starting from the user-unfriendly initial position. Starting the previous night, the captain steers Northwest. If he can manage a 45-degree course, half his movement is in the direction he wants to go in Leg 1.

When the wind shifts, the captain turns 90° to port, so that he is now heading North-east. Again, about half his movement is in the direction he wants to go, and so far, everything has been at maximum efficiency, i.e. the best speed possible.

That stops being the case when the ship crosses the dashed line, because the winds shift to a base north-south configuration, and the daytime is in the wrong direction. If he has enough masts, though, he can continue going a little bit north of east. or he can turn to head due East until the afternoon change in base wind direction. The whole purpose of the day’s maneuvers is to ensure that when this happens, the ship is within that shaded zone – and favorable winds will then generally put the ship into port in short order.

If you can predict the wind, however vaguely and uncertainly, you can manipulate the situation to your advantage.

4.8.7.14.6 Becalmed

Beaufort Scale 0 and 1 is not enough wind to get any ship moving. You are Becalmed, and the only thing you can do is wait and hope.

Beaufort Scale 2 is enough for Pinnaces and Sloops. Everything else is still Becalmed, and not going anywhere.

Beaufort Scale 3 is enough to get most vessels moving, however slowly – but ‘most’ is not all. Vessels of significant inherent weight, or that are fully laden with cargo, may not quite get going – that’s up to the GM. They have to wait for at least Scale 4 winds.

4.8.7.14.7 Unfavorable Winds

The only thing worse than being becalmed is having the wind come from completely the wrong direction. With Barques and Pinnaces, they have sail configurations that can overcome this problem (see 4.8.7.15.7 below) – everything else has a choice: drop anchor and furl sails and wait it out, or furl sails and deploy oars. Lots of oars – see 4.8.7.15.6.

Sometimes (but not always) it is possible to position the ship so that the winds are at least Tolerable, enabling you to keep moving, even if only slowly. If the winds are strong enough, you might even get a decent rate of speed up. If even a little of the motion is in the desired direction, you can tack back and forth, zigzagging your way to where you want to go.

Some vessels are better at this than others – sloops and Light Frigates and Extreme Clippers, for example, are very good. Beyond those three, it’s all about turn mode – if you ship is not very maneuverable, you can’t tack very well. As a general rule, the Turn Mode doubles the number of lengths of the ship that it takes to execute a 90-degree turn (1/3 this for a 30 degree turn, 1/10th for a 9-degree turn – you get the idea).

So a turn mode of 5 is twice as bad as a turn mode of 4, which is twice as bad as a turn mode of 3, and so on.

On top of that, the GM can add penalties for a ship being large / over-sized, or for a ship being fully laden (+1 turn mode for either), and for any sail damage. (A 50% damaged sail has only half the usual efficiency).

4.8.7.14.8 Violent Winds

Did I really say that the only thing worse than being becalmed was Unfavorable Winds? Well, from a plain English point of view, that’s a valid statement – but ‘Unfavorable’ has been given a specific, restricted, meaning within the system, and by that usage, even worse than winds coming from the wrong direction are winds strong enough to damage the vessel.

This is where being big helps instead of hindering; the presumption is made that heavy ships are stronger. This alone can be enough to drop the effective Beaufort number by 1 for the purposes of dealing with the effects of violent winds.

     ★ Square the Beaufort Number, multiply by the number of masts, then divide by the ship class number to get the number of dice of damage that the wind inflicts every 30 minutes.

     ★ Ships can ignore 1.5 points of damage for each class number.

EG1: Beaufort 5, three masts, Class 23: 5^2 = 25, × 3 = 75, / 23 = 3.26 d6, round down to 3. Maximum result of 18, vs Resistance of 23 × 1.5 = 34.5 (round down to 34). This is not going to damage the ship.

EG2: Same ship, Beaufort Number 7. 7^2 = 49, × 3 = 147, / 23 = 6.39, round down to 6. Maximum result of 36, so there is a possibility of slight damage.

EG3: Same ship, Beaufort Number 9: 9^2 = 81, × 3 = 243, / 23 = 10.56 d6, round down to 10. Maximum result of 60, average result of 35; vs resistance of 34 – the ship will take damage, and enough damage can sink it.

Furling sails reduces damage to sails and masts to 10%.

4.8.7.14.9 Extreme Winds: Hurricanes etc

Beaufort Number 10 Winds are when the trouble really starts.

Instead of squaring the Beaufort Number, Square double it (or simply multiply the number of dice by 4).

EG Same Merchantman, Beaufort Number 10: 10^2=100, x4 = 400, x3 = 1200; / 23 = 52.1 d6, round down to 52. Minimum result 52 vs resistance of 34 – ever 30 minutes, the ship will take damage. Average result, 148 pts over resistance. Maximum result 278 points over resistance. Furling sails reduces actual damage to 27.8 points, maximum – so no damage. Don’t expect that to be the case at Beaufort numbers 11 and 12, however.


4.8.7.15.6 Unfavorable Winds / Currents – Oarsmen Requirements

     ▪ Divide the total weight of the ship and cargo by the number of oarsmen.
     ▪ Divide their average Carrying Capacity by the result and multiply by 264 to get it in feet / minute.

     ▪ Divide that by 3.281 to get m / min.
     ▪ Divide m / min by 26.82 to get mph.
     ▪ Divide mph by 1.609 to get km/h.

Stop whenever you have a unit of speed that is appropriate to the scale of your maps.

Another way of looking at it: Total Carry Capacity of the Oarsmen has to exceed the total weight of the ship and cargo or it’s not going anywhere under oar power.

4.8.7.15.7 Unfavorable Winds / Currents – Sail Solutions

As mentioned, Pinnaces and Barques have a sail configuration that lets them sail straight into the wind – albeit slowly.

But I did once hear about an enterprising if desperate crew in a pirates game who cut down two of their three masts on a merchantman so that they could sew the sails into an over-sized version of this solution, improvising the rigging required. I forget what the GM in question rules, but in my book the inconvenience and loss of efficiency caused by the loss of the two masts was quite enough to make up for permitting this solution to work. But, given that the ship now had less than the usual minimum number of sails, efficiency would have been compromised accordingly.

Still, desperate times…

4.8.8 Currents & Waves

Being becalmed may not be the end of the world. Currents alone can provide motive power, although far less speedily than wind power.



This satellite photo released into the public domain by NASA has been edited to show the major currents of the world’s oceans and seas by Ingwik and released as a derivative work under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Currents flow not only horizontally but vertically, cycling up and down as they travel. To a ship on the surface, this effectively means that they wax and wane.

The Wikipedia page on Ocean Currents has a long list of currents that you can draw upon for further information, and there are more detailed maps available, too.

I’m not going to go into all the effects that they have; all I’m concerned with here is their direction and speed.

It’s important to note that there can be different currents at different depths, just as there can be different winds at different altitudes at the same time.

Surface currents are predominantly caused by wind, and – where possible – will be in the same direction. However, they have to turn away from that direction if there is land in the way, and the direction they turn is away from the equator – unless there’s a land mass between the wave and that geographic feature. But the shape of the land and all sorts of other factors can complicate this simple principle.

     ★ Look for the largest, strongest current in the vicinity, even if it’s not directly affecting the vessel’s location.

     ★ If it IS affecting the vessel, job done.

     ★ if it isn’t, one of two things will happen: a side current, or a reverse current.

A Side Current is basically a smaller curve looping off a larger one. They are a LOT smaller and weaker than the main current.



A Reverse Current interacts like two gears, with one gear being a side current:



Well, actually what happens is that variations in the major current creates a short-lived low pressure zone which gets filled with water from surrounding layers – but more tries to rush in than will fit, and this movement of water has momentum, and as the variation travels around the main current, additional water pushes against the water already moving in the other direction, and you end up with a much weaker current going in the reverse direction of the main current.

You can also get side-currents within a reverse current:



And, anywhere where the land varies greatly in its proximity to the main current, you can also get reverse currents:



… so it’s complicated.

The strongest current on earth is the Antarctic Circumpolar Current, which averages 10m / second (600m / min = 36 km/h), 5 times the strength of the far better-known Gulf Stream. Lesser currents range down to a couple of knots – refer to the Beaufort Scale tables to see just how low that is. The Gulf Stream and the Kuoshio Current are fast currents, moving about 2m per second (120 m / min or 7.2 km/h).

Tidal currents are caused by the positions of Earth and Moon and vary greatly in strength, even from one hour to another. Some locations experience much stronger / greater tides than others and stronger tidal currents are one of the results. Strong Tidal Currents can reach 8 knots or more.

Deep water currents are driven by density differences, and variations in water temperature and salinity (both of which trigger density differences in water). They move much slower than Tidal and Surface currents (but I couldn’t find an exact number, so I’m going to assume from the “much” that we’re talking about more than the Gulf Stream to Antarctic Current ratio and assume a factor of 10).

     ★ Using the above as a guide, estimate the strength of the major current in whatever units are most convenient.

     ★ A side-current will have about 1/4 the speed / power.

     ★ A reverse current will have about 1/10th the speed/power.

     ★ A side-current of a reverse current will have about 1/25th the speed/power.

     ★ A reverse current powered directly from the main current will have about 1/4 the speed/power of the main current.

     ★ A tidal current can add to another current, subtract from it (possibly overwhelming it), or be off at an angle to it, producing a compound current:



The diagram above demonstrates 12 different compound currents.

Figure 1 shows a Tidal Current adding to a Surface Current in the simplest possible configuration, exactly the same line.

Figure 2 shows the opposite, with the tidal current opposing the surface current. In this case, the tidal current is not enough to completely cancel out the surface current.

Figure 3 makes the Surface Current weaker and the tidal current stronger – now the tidal current is diminished but not overcome by the surface current.

Figure 4 shows a slightly more realistic situation in that the two currents are now in different directions. The results are our old friends vector sums.

Figure 5 uses a stronger tidal current for comparison to figure 4.

Figure 6 shows a slightly weaker surface current and a tidal current of the same strength but at an acute angle.

Figure 7 has the same configuration but a much stronger tidal current – so much so that the compound current is more than at right angles to the surface current.

Figure 8 has the same surface current but this time the small tide is at an oblique angle. The compound current is stronger as a result.

And Figure 9 shows an increased Tidal Current but is otherwise unchanged. The compound current shifts direction but only by a little, but it becomes much stronger.

Figure 10 is the first of three multi-hour compound charts. In this example, I’ve kept the surface current the same and varied the tidal current – again at right angles to the surface current. It starts strong, weakens, then the tide starts to go out, and finally, it becomes stronger again.

Figure 11 has the same configuration but with a surface current that is also varying – probably a bit more than normal, to be honest.

Finally, Figure 12 varies the angle of the surface current as well as it’s strength, and is the most realistic demonstration of the compound current that results.

     ★ Use the information provided to estimate the average strength of the respective surface and tidal currents.

     ★ Select the next smallest die size and roll it; subtract the result from the current’s strength. EG 7 knots minus 1d6 because 6 is the next smallest result from 7.

     ★ Using the diagrams, visualize the resulting compound tide’s direction and strength. Don’t worry too much about accuracy.

     ★ The longer the ship, the greater the effect side-on to the current, maybe as high as 25% efficiency. The wider the ship, the greater the effect when running with the current, maybe as high as 10% efficiency. In both cases, it can dip to as little as 3% going the other way.

     ★ The faster the ship, the more sleek and narrow it is. The larger its cargo capacity relative to its length, the broader it is. Using this information, guesstimate the proportions of the ship, and from them, the amount of speed that the currents will impart to it.



Image by Brian Kingston from Pixabay

I’ve saved the above image until close to the end of this article for a very good reason: take a look at the surface of the sea depicted, and you can tell that the current and wind are operating in different directions from the shape of the foam caused by the breaking waves ahead of the storm. Initially, you can’t tell which one is from the left and which one is coming rear-to-front or vice-versa, but look at the sails and the way they have billowed out and it becomes clear – the ship is running with the wind and across the current, exposing the broad side of the ship to that current, which will be pushing it just a bit left-to-right.

4.8.8.1 A brief note on Sea Anchors

A lot of people think that sea anchors work by digging into the sea floor. Such people have no appreciation for the depth of the sea, and how much chain would be required to lower the anchor that far, and how long that would take, and how much it would weigh.

Nope, not happening. It’s the weight of anchor and chain dangling in the water that slows a ship’s movement (it doesn’t stop it) – because the subsurface currents are so much weaker, and potentially in a completely different direction to the surface currents.

That means that the anchor can’t move as fast as the surface current tries to move the ship, and so it holds the ship more-or-less in place, the chain snapping taut. If the surface current is too strong – which can happen in a hurricane, say, or anytime wind and currents combine – it can even snap the anchor rope.

Anchors can and do drag ships, and if there’s a hazard close by in that direction, and the current in which the ship is anchored is strong enough, captains may be forced to cut away the anchor and let it – and most of the chain – fall to the bottom in a bid to save his vessel.

4.8.8.2 Favorable Currents

As with winds, favorable currents are currents that push the ship in the desired direction. Currents are often best viewed as a modifier to the direction of wind – the stronger the push on the ship, the stronger the impact, but it all has to be relative to the wind speed.

More accurately, the speed that the current imparts to the ship has to be assessed relative to the speed that the winds impart to the ship, so both are a question of the efficiency of this conversion. The effective force of the wind depends on the amount of sail being presented to the wind and the relative angle of the wind to the ship; the more unfavorable the wind, the more scope there is for currents to have an effect.

4.8.8.3 Still Currents

Still currents – the equivalent of being becalmed – are fairly rare, but they do happen – especially if a ship finds itself in a situation of current shear, where two currents ‘rub shoulders’ but flow in opposite directions. Take another look at the illustrations of side currents, and you can see that where two side currents exist side to side, this can be the case. However, it requires that the main current also be weak (because it moves those side currents with it).

Unless you are also becalmed, this won’t bother captains too much. When the winds have also dropped, though, it’s time to think about which of the maritime gods you may have offended, and what you can do about it.

4.8.8.4 Unfavorable Currents

Obviously, UNfavorable currents are those that push the ship into danger, or that oppose the winds, in whole or in part. A ten-knot current – very strong – can (if it’s in the wrong direction) slow your forward speed by… a couple of knots. Keep things in perspective – currents are a minor influence compared to winds, unless and until you become becalmed or furl the sails.

4.8.8.5 Violent Waves

Big waves, on the other hand, can pose an existential threat to the ship. The density of sea water varies from 1020 to 1029 kg / m^3. So, a wave 20m long and 1m high is essentially a shape like one of those below:



Wave shape #1 is low-velocity, gentle, rolling. It has a volume of 1 × 20 × 1/2 × 2, 3, 4, or 5m – so 20-50 m^3. It weighs 20500-51250 kg. Perhaps tonnes? 20.5- 51.25 of them. Or short tons? 22 – 56.5 is the number.

But the heavier the wave, the slower it’s moving, so the less damage it will do. We’re talking nothing more than Beaufort Scale 3, and probably less. That’s a wind speed of 5.4 m/s, tops, and 1/2 m v^2 gives kinetic energy of 1/2 × (20.5-51.25) × 5.4^2 = 10.25-25.625 × 29.16 = 299-747 whatevers – I’ve mixed units terribly for convenience, but that doesn’t matter so long as I use the same ones for the other shapes.

Wave shape #2 shows a wave not yet breaking but being pushed by the wind. It has a volume of 1/2 × 1 × (2.5-3.5) × 20 = 25-35m^3 and a weight of 25625 – 35875 kg or 25.625-35.875 Tonnes. These are the waves you get from Beaufort scale 5 winds, maybe 6, so 13.9 m/s. Kinetic energy = 1/2 × (25.625-35.875) × 13.9^2 = (12.8125-17.9375) × 193.21 = 2475.5 – 3465.7 whatevers – so the wave weighs about as much as the middle value for wave 1, but hits with 5-8 times as much energy.

Wave shape #3 shows breaking waves, and 1m tall is rather on the small side for them. It is presumed that the two shaded areas are roughly equal in size, so this is still (effectively) a simple triangle. So the volume is about the same as shape #2 and so is the mass. Here, we’re talking Beaufort Scale 7 or maybe 8, and 17 m/s winds. Kinetic Energy is 1/2 × (25.625-35.875) × 17^2 = (12.8125-17.9375) × 289 = 3702.8 – 5184 whatevers – almost 1 1/2 times as much force as wave #2 and 7.5 – 12 times what the gentle waves were doing.

But if I scale that up to what the wind speed says the waves should be, in height: 13-19′ waves = 3.9624 – 5.7912 m in height = 4 – 5.8 times as much volume = 4 – 5.8 times as much mass (102.5 -208 Tonnes) = 4 – 5.8 times as much kinetic energy, or 6 – 8.7 tomes as much as Wave #2 – and 30 – 70 times as much as the gentle waves.

That’s a Blue Whale at 38 mph hitting the side of the ship – every 2 or 3 seconds.

And that’s just the edge of the dangerous winds part of the Beaufort Scale. A full-scale hurricane, with 34 m/s winds, would be 4 times as bad even if the waves were no larger, which they would be, by a factor of almost 2.75. Between them, around 11 × the striking power of Wave #3.

And such waves would almost certainly be longer than the 20m used here – potentially as long as the ship, which is as long as it gets.



Some pictures have been included for purely decorative, evocative, reasons!
This image is by Elias from Pixabay

4.8.8.6 Extreme Waves: Tsunamis & Walls Of Water

But the dangers at sea don’t end there. Tsunamis are really only a problem at port – the wave as it travels across the ocean is really quite gentle but extremely fast moving and containing a LOT of displaced water, which (in turn) is being pushed by the water behind it, and so on.

Once it hits shallows, though, there is nowhere for all that water to go but up into the air, and that’s when you get an appreciation of how much power it has. Whatever isn’t nailed down – including apartment blocks – is up for grabs. Ships will find themselves bottoming out on the sea floor as the normal water retreats out to see, and then being crushed beneath thousands of tons of water, being carted miles inland if they manage to survive it – before being swept back out to sea as the water retreats.

But Tsunamis don’t frighten most sea captains.

Rogue Waves are a whole different story.

These are like two sets of percentiles and getting 00 on all of them. Every little thing adds up to create a wall of water more than twice as tall as the waves around them. Like Tsunamis, they can also move at ferocious speed and in directions other than the prevailing winds and currents.

The biggest one ever recorded was 58 feet tall.

In most parts of the world, rogue waves are roughly 3 in 10,000 – but in some places, they can be 3 in every 1,000, because the shape of the land controls the shape of the water and focuses the energy of the waves.

They travel at 500 mph (800 km/h). At that speed, they can strike a wooden vessel and leave nothing but kindling without even noticing. They do slow down when approaching land – which only makes the water coming behind the wave front pile up on top of it, producing an even bigger wave.

It’s often speculated that, like several other weather phenomena, there is a wind equivalent of a rogue wave. Anyone who has seen footage of an Australian Dust storm hundreds of kilometers long, a wall of brown in the sky, has plenty of reason to believe it’s true.

Rogue Weather can and does scare any captain that knows about them.

4.8.9 Other Applications of the Weather System

The main weather system – thresholds and change accumulators – can be used to simulate a vast range of other phenomena, both natural and unnatural. Everything from meteor strikes to stock markets to the price of coconuts.

In fact, anything that has a cyclic nature of some kind, where trends accumulate until something has to give or a tipping point is reached, can be modeled in this way.

That’s because it’s built on the concept of variable length cycles operating concurrently – sooner or later, you’ll ht the jackpot.

Most of these phenomena are ferociously difficult to simulate, so if you need to track one, you could do a lot worse than carving out a variation of the base system offered here.

4.9 Exotic Modes Of Transport

In a fantasy world, these mundane methods might not be the only ways to get around. And that means that someone will think about using them for a business edge. I don’t intend to go into them in any depth, but it would be criminally negligent not to at least mention them.

4.9.1 Flight

Ah, flight. The dream of man ever since he first clapped eyes on a bird – which, since they predate our evolution, was measured in seconds from the time our species was born.

There are three ways to fly.

You can ride a flying creature, in which case the cargo capacity is whatever it can carry and stay airborne, less your weight.

You can ride a flying contrivance, like a magic carpet or a hot air balloon, in which case area covered is a big deal – no part of the load can exceed the edges of the contrivance in question or you risk losing it. On top of that, there will be weight restrictions. But these are often poorly defined, so it’s going to be up to the GM to overcome any gaps or shortcomings.

Or you can cast a spell on someone, in which case they are restricted to whatever load they can carry.

Flight is great for getting something somewhere, fast – but until the wright brothers and several generations of aircraft follow them, cargo capacity is infinitesimal.

Duration of Flight is another hugely limiting factor. You may be able to travel five times as fast as a horse – but you’ll almost certainly be on the ground again a long time before that horse runs out of oomph for the day.

4.9.2 Teleport

Teleport spells also usually affect an area, or the individuals within an area. So they are restricted, in terms of travel, in much the same way that flying is – but with far greater range.

4.9.3 Magic Gates & Portals

This is where things get more interesting. Essentially, these abolish the distance between points A and B – anything that can physically fit through the portal is fair game.

If it can fit into a caravan, and that caravan can fit through the portal or gate, you’re in business.

Some GMs impose additional restrictions on teleporting and gate / portal travel to keep things from getting out of hand, for example having portable holes and magic bags turn inside-out. This effectively restricts traders to what they can carry, either personally, or in a wagon of some sort.

It’s important to recognize that gates and portals are strategically-important targets. If you conquer a Kingdom that sports one, you can find enemy forces in your back pocket at any time. That makes capturing them a very high priority.

Some will decide that having such things around is a lot more vulnerability than they are worth, and may seek to destroy them. That’s a problem if you’ve built a business around them still being there.

As a general rule, exotic modes of transport can’t compete with the bulk carrying capacities of more mundane choices. But they can add a lot of color.

Finally, chapter 4 is complete! It has thrown tentacles out in various unexpected directions along the way, but I got there! This is going to posted late – it’s 40 minutes past deadline as I speak and it still needs to be spellchecked and formatted and so on – but it is done!

Next week is scheduled to be a time-out post, and I’m not sure what’s doing the week after because I know I’ll be away for part of the weekend at a family gathering. If I can get a post done in time, it will be something short – another timeout, almost certainly.

Until then, have fun at the table!

Finally! After the diversions caused by Rafts and boats, today the series focuses on Ships at sea, with a bonus sci-fi section or two on the side.

The original plan was to also include Weather at Sea and Exotic Transportation Modes but the former has quickly grown to the point where the post would not be ready to publish if I insisted on including it.

So, even though I’ve put 1900 words into it already, those sections have been excerpted from this post and relegated to part 13, soon to follow – I have some original game mechanics for weather that I want to get down on ‘paper’ before I forget them, so I will be trying to strike while the iron is hot!

Unfortunately, there also wasn’t time to convert my quick-and-dirty spreadsheet into a fully-functional version to give away as a bonus freebie. Besides, if I did one for rafts – a minor side-note within the bigger topic – I would then have to ask why I hadn’t done one for more important parts of the system, and the answer of “too complicated, too little time” would have sounded rather hollow. The process is there and clear, and that will have to do, I’m afraid.

Table Of Contents: In part one of Chapter 4: Modes Of Transport

4.0 A Word about Routes

4.0.1 Baseline Model
4.0.2 Relative Sizes
4.0.3 Competitors
4.0.4 Terrain I
4.0.5 Terrain II
4.0.6 Multi-paths and Choke Points

4.0.6.1 Sidebar: Projection Of Military Force

4.0.7 Mode Of Transport

4.1 Backpack / Litters / Shanks Pony

4.1.1 Capacity
4.1.2 Personalities / Roleplay

4.2 Horseback

4.2.1 Capacity
4.2.2 Requirements
4.2.3 Personalities / Roleplay

4.3 Mule Train

4.3.1 Capacity
4.3.2 Requirements
4.3.3 Personalities / Roleplay

4.4 Wagons

4.4.1 Capacity
4.4.2 Requirements
4.4.3 Other Exceptions – Animal Size

4.4.3.1 Sidebar: Road Trains

4.4.4 Fodder / Food & Water Needs

4.4.4.1 People
4.4.4.2 Horses
4.4.4.3 Mules
4.4.4.4 Oxen / Cattle
4.4.4.5 Elephants
4.4.4.6 Other

4.4.5 Personalities / Roleplay

In Part 2:

4.5 River Boats & Barges

4.5.0 A Splice Of Maritime History

4.5.0.1 Dugouts & Canoes
4.5.0.2 Rafts
4.5.0.3 Boats
4.5.0.4 Poled Rafts & Barges
4.5.0.5 Oars
4.5.0.6 Land-based motive power
4.5.0.7 Sail
4.5.0.8 Better Sails
4.5.0.9 Trading Ships
4.5.0.10 Warships & Pirates
4.5.0.11 Beyond the age of sail
4.5.0.12 Riverboats
4.5.0.13 Sources

4.5.1 Riverboat Capacity
4.5.2 Favorable Winds

4.5.2.1 The Beaufort Wind Scale

4.5.3 Favorable Currents
4.5.4 Unfavorable Winds / Currents – Oarsmen Requirements
4.5.5 Unfavorable Winds / Currents – Sail Solutions
4.5.6 Extreme Weather Events
4.5.7 The Tempest Scale
4.5.8 Vessel Rating
4.5.9 Weather Cataclysms

In Part 3:

4.6 Rafts

4.6.1 Rowing Time & Exhaustion
4.6.2 The basics of vector sums

4.6.2.1 An Example
4.6.2.2 A better example
4.6.2.3 With Maths
4.6.2.4 Simplified Vector Sums
4.6.2.5 Multi-hour Vector Sums

4.6.3 Raft Design & Operation

4.6.3.1 Buoyancy
4.6.3.2 Raft Calculation Process
4.6.3.3 Why all this matters
4.6.3.4 Category 1 Raft Table
4.6.3.5 Category 2 Raft Table
4.6.3.6 Category 3 Raft Table
4.6.3.7 Category 4 Raft Tables
4.6.3.8 Category 5 Raft Tables
4.6.3.9 Category 6 Raft Tables

4.6.4 Overloaded Rafts
4.6.5 Raft Breakup
4.6.6 Construction Time
4.6.7 A final word on Overloading Capacities

4.7 Canoes etc

4.7.1 Proportions
4.7.2 Frontal Dimension
4.7.3 Base Speed

In today’s post:

4.8 Seagoing Vessels

4.8.0 Logistics At Sea and In Space

4.8.0.1 “But I don’t need to know this stuff, my PCs aren’t Space Traders…”
4.8.0.2 Using the analogy
4.8.0.3 A Word on Historical Accuracy

4.8.1 Capacity
4.8.2 Ships As Monsters
4.8.3 Ship Specifications

4.8.3.1 Physical Dimensions
4.8.3.2 Movement Parameters
4.8.3.3 Functionality
4.8.3.4 Combat
4.8.3.5 Data Sources
4.8.3.6 Ship Specifications

4.8.4 Some Thoughts About Cannon

4.8.4.1 Having Your Cannon And Your Flavor, Too
4.8.4.2 Crippled Land-Cannon
4.8.4.3 Personal Firearms
4.8.4.4 Bombs and other explosive devices

4.8.5 Exotic Crews

4.8.5.1 Human Height Adjustments
4.8.5.2 Non-human Height
4.8.5.3 Non-human Proportions
4.8.5.4 Crew Strength
4.8.5.5 Handling and other parameters

4.8.6 Mixed Crews

In the next post:

4.8.7 Weather At Sea

4.8.7.1 An Introduction to Weather (oversimplified)
4.8.7.2 Accumulated Potential and Threshold
4.8.7.3 Seasonal Weather Averages
4.8.7.4 Seasonal Weather Trends
4.8.7.5 Daily Temperature Variation
4.8.7.6 Weather Change Threshold
4.8.7.7 Humidity
4.8.7.8 Clouds & Rain
4.8.7.9 Winds

     4.8.7.9.1 Favorable Winds
     4.8.7.9.2 Becalmed
     4.8.7.9.3 Unfavorable Winds
     4.8.7.9.4 Violent Winds
     4.8.7.9.5 Extreme Winds: Hurricanes etc

4.8.7.10 Currents

     4.8.7.10.1 Favorable Currents
     4.8.7.10.2 Still Currents
     4.8.7.10.3 Unfavorable Currents
     4.8.7.10.4 Violent Waves
     4.8.7.10.5 Extreme Waves: Tsunamis & Walls Of Water

4.8.7.11 Unfavorable Winds / Currents – Oarsmen Requirements
4.8.7.12 Unfavorable Winds / Currents – Sail Solutions

4.9 Exotic Modes Of Transport

4.9.1 Flight
4.9.2 Teleport
4.9.3 Magic Gates & Portals
4.9.4 Capacities

And, In future chapters (most of them much shorter):

5. Land Transport
6. Waterborne Transport
7. Spoilage
8. Key Personnel
9. The Journey
10. Arrival
11. Journey’s End
12. Adventures En Route

4.8 Seagoing Vessels

The defining trait of ships is that anything other than sails or mechanical power is a secondary or backup form of motive energy. Seagoing vessels are an order of magnitude more complicated than river trade, but potentially an order of magnitude more profitable as well.

In many ways, deep-water sailing vessels are the nearest thing in Fantasy to Interstellar Trade in a Sci-Fi game, for exactly the same reasons: You are a long way from anywhere, so if you need something, you had better have taken it with you.

When you’re miles (or light years) – perhaps a dozen, perhaps hundreds – away from an established port, you can’t exactly nip on down to the corner store any time you feel like it.

That means that a lot of planning has to go into these expeditions; they have far more stringent personnel needs, and far more rigorous preparations that have to be made, or they might never leave port.

Those needs have been in the back of my mind throughout this project, and have had considerable influence over the Key Personnel chapter, for example.

Before I get into the broad mechanics of sea travel, though, I want to talk a little more about the logistics of these voyages.

4.8.0 Logistics At Sea and In Space

Over time, people will have learned from successful trading voyages and a few unsuccessful ones, too, I would imagine. They would have learned that there are certain risks involved which could lead to catastrophic failure, but that if you have this, and someone on the crew knows how to do that, there is at least a chance (if not a certainty) of staving off that disaster.

Having the right resources and personnel is a form of insurance; not having them is something that you might get away with, time and again – but sooner or later, it would come back to bite you.

If you could carry everything you might possibly need, there would be no problem, but you can’t. Some things are too big or too expensive to justify, given the relatively low risk that they will be needed. That alone makes for competing imperatives and interesting choices, but there is a third factor: every kilogram or pound of resources that you carry will occupy space that is therefore not available to be used to carry cargo, and its’ cargo that pays the bills.

You would never carry a spare keel, for example – if the one you have happens to break in a storm, well that’s just tough luck, that vessel is probably headed for the bottom (unless you manage to limp into port somewhere or make landfall, and can then craft and install a replacement or repair – a singularly difficult and improbable task).

You wouldn’t carry a replacement mainmast – if yours gets blown away, you have to make your way to land and again see about constructing or buying a replacement. But you might be able to save the one you already have just by cutting the ropes attaching your mainsails and letting them blow away – and storms happen often enough that it would be worth carrying one or perhaps even two spares.

Anchors are essential, but large and heavy – they are probably a borderline spare. More likely, you would carry a smaller, lighter, emergency anchor with which to make do, temporarily.

Ships need a certain level of crew, but people die at sea all the time (especially in a fantasy environment), so anyone who doesn’t carry spares has rocks in their head. But those people need food and water, and you have to carry that, too – so getting the numbers right is another vital decision. And carrying someone who can keep them healthy is definitely desirable. And someone who can prepare that food.

In fact, it’s in the food-and-water department that the greatest differences between space trading and sea traders can be found – because those who travel the oceans are surrounded by water, and that water contains food, in the form of fish.

The problem is that you can’t stop to fish – who knows what the winds will be like tomorrow? If the wind is even half reasonable, you have to take advantage of it while you can. And as for sea water, you can’t drink it.

It’s possible, were the ship to be becalmed, that you could set the crew to fishing and purifying sea water, but you will never produce enough of either commodity in that way, and you’re often better off putting the crew to work rowing toward someplace where the winds are more likely to be useful and reliable.

In space, it might be possible to find a source of potable water in the form of ice – it would need to be melted and filtered, but that’s a relatively easy operation. But there is no likelihood of food, so that side of things is worse.

All of which means that navigation is vital – in both instances. And so it goes, on down the line.

4.8.0.1 “But I don’t need to know this stuff, my PCs aren’t Space Traders…”

Someone actually said this to me at one point. To anyone thinking that way, I would ask, Do your PCs ever need to buy anything not made locally? Do they ever need to use a service provided ‘on the side’ by traders? Do they ever interact with any NPCs who do trade, or who try to protect traders from pirates? Do you ever need to take trade patterns into consideration when assessing the viability of outposts and colonies?

If the answer to any one of these questions is ever even just a little bit “yes,” then you need to have a grasp of the basics and of what a trader needs to know in order to be prosperous.

You might not need to take every trade exchange into detailed consideration, but you need to know the basics, just so that you can do a reasonable job of integrating them into your campaign environments.

Use sea trade, then, as an analogy to your situation when thinking about interstellar trade, and you will have everything you need to succeed at at least this minimal level.

Okay, so where was I? Oh, yes….

4.8.0.2 Using the analogy
The principle is, then, that anything that can be encountered by a ship at sea will have some analogous encounter for a ship in space, and vice-versa. These encounters won’t just affect trading vessels, of course; any ship that journeys from Port A to Port B, for any reason, can have one.

Let’s say the PCs have undertaken some task with a firm deadline, but one that they should be able to meet easily. That doesn’t suit the GM; he wants them to be under some time pressure so that when real problems arise later in the adventure, the PCs can’t make the lazy decisions, they will have to take a few risks. But how to delay them long enough to make time more critical?

How to delay them? is therefore the question, and to answer it, the GM deploys this analogy and thinks of all the things that could delay a merchant ship going to sea.

     ▪ A paperwork snafu delays departure.

     ▪ While at sea, encounter a Beholder.

     ▪ Becalmed.

     ▪ Pirates.

     ▪ A military vessel hunting pirates who is suspicious of the PCs ship.

First question: one delay, or several smaller ones? The GM decides to have an each-way bet: one longer delay, Becalmed, and several smaller ones that can be dropped in or left out as needed to achieve the total delay desired.

Second question: How much delay does he want? Somewhere between 1 and 2 weeks, he decides. That’s not enough to make time a critical factor, but it is enough to make the timetable uncomfortably tight.

Third through seventh questions: what are the equivalents of the maritime problems that he has listed?

     ▪ A paperwork snafu delays departure. Unchanged, really, it just needs a bit of fleshing out.

     ▪ Beholder. Some equivalent creature might reside in an Asteroid belt that the PCs have to traverse on their way out of the system. Give it powers useful to a space-going creature – beams from some of its eyes that are adept at locking onto and destroying incoming missiles; some sort of x-ray vision; something that penetrates hull armor; something that ablates or drains shields. Have it live on something in the engine compartment (details depend on game background); it uses it’s x-ray vision to search for it and its powers to go after it. Once driven off / defeated, the ship will need temporary repairs to be space-worthy. Or they can return to their departure point and get the repairs done properly – at the cost of even more time.

     ▪ Becalmed. A ship jumps into hyperspace just as the PCs are arriving, and it’s evident that it was not properly configured, causing it to misjump. If the game system uses jump gates, maybe this causes the gate to malfunction, and the PCs can’t go anywhere until it’s repaired. If the ships generate their own jumps, as in Travelor, maybe a misjump ‘curdles’ space making misjumps more likely even if the ship is properly configured. All the PCs can do is wait for space to ‘calm down’. Or maybe an Asteroid has impacted a nearby gas giant and kicked up a super-storm of gas-giant proportions, and it’s the radiation and electrical discharges that make FTL travel unsafe. Lots of options, pick an appropriate one.

     ▪ Pirates. Self-explanatory, but largely done to death. The focus should be on making this pirate encounter distinctive. Maybe they have heard rumors of an incredibly valuable shipment coming through and won’t believe the PCs when they say ‘it’s not us’? Rare, 20th century comic books perhaps, or something else equally attention-getting? I remember the outrage amongst my players when the original Kermit The Frog puppet was listed amongst some recovered stolen property… After the battle, the ship might need repairs. Again.

     ▪ A military vessel hunting pirates who is suspicious of the PCs ship. Again, fairly self-explanatory. They would insist on boarding, would search the ship and demand proof of purchase for anything and everything that might, or might conceal, cargo. Which might be especially problematic if the mission is to smuggle something somewhere.

Each problem (other than “Becalmed”) might be resolved in 1 or 2 days with a successful check of the appropriate skill, or 2-3 days with an unsuccessful one. The PCs can be “Becalmed” for 4, 6, 9 days, that’s up to the GM. There should probably be some sort of instrument that would warn the crew it’s unsafe to jump, and someone should be monitoring this and reporting back to the captain on a regular basis. This is a chance to delve into how the world works, don’t waste it! That means that if the PCs succeed in every check, 4-8+6 = 10-14 days elapse; a failed check simply takes one of the subsequent encounters off the list.

I would also rank the encounters in terms of game world / storytelling strength. As mentioned, Pirates are a bit of a cliche; so they would rank fairly low. The “Beholder” is a bit better, but stretches credibility a little thin. It’s next best. The Pirate hunter is pretty good, and might be encountered even in systems where there is little or no pirate activity. And the different FTL problems (“Becalmed”) are gold in terms of throwing the occasional spanner into the predictability that is often a feature of these games.

That gives a good idea of which encounter to drop, if need be. Logically, the pirate hunter should be at the destination, not in the departure system – but if you change them to be hunting smugglers, that can work, too. So the sequence can be tweaked as well.

I would be careful about putting the two weakest encounters after the “Becalmed” sequence, though; one weak encounter and one stronger one are a better mix in terms of sustaining interest and entertainment throughout.

I have seen travel to a jump point, jump, arrive, and travel to destination hand-waved down to three minutes game time and a skill check; I’ve seen it take an hour or so, game time; and I’ve seen it occupy a full game session. This 1-2 week delay is closer to the latter.

And, to state what should be obvious: No, you don’t do this every time. You save it for when it adds story value to the game – like shortening a deadline to the point of discomfort.

4.8.0.3 A Word on Historical Accuracy

Don’t expect more than a bit of lip service to this concept herein. Trying to compress the entire maritime history through to the end of the age of sail into a coherent and cohesive system requires massive generalization and more than a little romanticization, even before allowance gets made for any Fantasy element.

Functionality and a superficial credibility were far higher priorities than accuracy or realism.

4.8.1 Capacity

Seagoing vessels tend to be fairly big, and that generally means that the size of a Trade Unit tends to be larger as well. As a general rule, 1/2, or 1, 2, or 4 tons (or tonnes) are probably the most practical sizes for this kind of cargo transportation. That increases the size of a Labor Unit as well, because there is more to be handled – loaded or unloaded – in a given time frame.

All ships are NOT alike. There are huge variations in design and capacity. Some trade capacity for speed, the better to run away; others bulk up on defenses, the better to survive; and some aim for the maximum cargo.

Not all ports are able to handle ships of every size. The larger the vessel, the deeper the water that it needs (as a general rule of thumb).

So cargo capacities are specific to each ship design and limited by what the ports can handle on a trade route. Or, more properly said, cargo capacities are specific to each ship design and trade routes are restricted by the size of the ship.

And don’t forget that supplies and operational reserves eat into the cargo capacity.

Crew sizes are also generally proportional to the cargo capacity, because each increase represents an increase in the size of the ship.

There are 14 sizes that are reasonably common. Below, in a table, I set these out and cross-reference them with the listed ‘optimum Trade Unit’ sizes to get total cargo capacity in conventional units. After that, there are some modifiers for different optimizations.

But you should work backwards – select a vessel of appropriate size and type, reverse the adjustments to get cargo capacity, and then find that capacity listing in the column of your chosen Trade Unit size.

Cargo Capacity (Trade Units)	1/2 T = 1 TU	1 T = 1 TU	2 T = 1 TU	4 T = 1 TU
1	1/2 T	1 T	2 T	4 T
2	1 T	2 T	4 T	8 T
4	2 T	4 T	8 T	16 T
5	2.5 T	5 T	10 T	20 T
8	4 T	8 T	16 T	32 T
10	5 T	10 T	20 T	40 T
15	7.5 T	15 T	30 T	60 T
20	10 T	20 T	40 T	60 T
25	12.5 T	25 T	50 T	75 T
35	17.5 T	35 T	70 T	(140 T)
50	25 T	50 T	100 T	(200 T)
60	30 T	60 T	(120 T)	(240 T)
65	32.5 T	65 T	(130 T)	(260 T)
75	37.5 T	75 T	(150 T)	(300 T)
100	50 T	100 T	(200 T)	(400 T)

Notes:
() signifies vessels that did not exist in the historical periods commonly used as a basis for Fantasy games, even at a stretch – but that might exist in a Fantasy reality, nevertheless.

Units:
     1 Tonne = 1000 kg = 1.102 short tons = 2205 lb
     1 short ton = 2000 lb = 907.2 kg = 0.9072 tonnes
     1 long ton = 2240 lb = 1.12 short tons = approx 1.016 tonnes = 1016 kg

Long tons are used for the displacement (weight) of vessels.

Cargo is supposed to be recorded in short tons, but this only generates confusion and opportunities for fraud (using long tons for cargo to reduce mooring fees and sound tolls [a toll for using the strait separating Denmark and Sweden that for 200 years generated up to 2/3 of Denmark’s state income], for example).

It’s also useful to notice that, to two significant digits, the difference between tonnes and long tons is a rounding error.

4.8.2 Ships As Monsters

It can often be useful to use standard combat as an analogy for naval battles – hit points, armor class, etc. While not going fully down this path, there have been any number of tips of the hat to the idea in the content that follows.

If you decide to commit to this more fully, just remember that – unlike monsters – (1) there is no flanking advantage; (2) ships will keep going – unlike monsters, they won’t stop on a dime – and collisions between ships can easily sink both; (3) it takes time to furl or open sails. How long depends on all sorts of factors, and is better left up to the GM;.and (4) ships tend to be big and heavy, and even though there isn’t a lot of friction to overcome, they are still going to be slow to get moving even when sails have been hoisted or engines engaged.

4.8.3 Ship Specifications

4.8.3.1 Physical Dimensions

Ship sizes may include Small / Light*, Medium, Heavy / Large, and Over-sized.
     * These are also sometimes called “Pocket” ships
Ship Sub-types may include Fast (optimized for speed at the expense of other attributes) and War (optimized for offensive capacity at the expense of other attributes)

Length: typical length in feet, but every ship will be a little different

Weight (empty):typical weight in long tons, but every ship will be a little different

Masts (normally): 0, 1, 2, 3. 4+ was possible but rare, and assumed to be ‘fantasy’ in nature.

4.8.3.2 Movement Parameters:

Turning Circle: 1 Very Tight, 2 Tight, 3 Moderate, 4 Wide, 5 Very Wide, 6 Incredibly Wide.

This is usually measured as a multiple of fudge* × length × speed / 4.

The actual meaning of these turning circles depends on the map scale, wind conditions, and too many other factors to go into here. GMs should decide what they mean on the day and under the current in-game conditions – while noting that each is worse / wider than the one before. GMs aiming for realism should note that the extra speed from a wind at the stern actually permits a tighter turn, while any wind from square of the hull forward increases turning circle by 1 class to the worse.

Any ship with <1/4 max crew also adds 1 to the turning circle.

* Fudge is an adjustment that is consistent over a class of ship (usually) and is used to scale the turning circle designated by the GM to the scale of the ship. It’s what is commonly known as a ‘technical term’.

Speed: 8 = Incredibly Fast, 7 = Very Fast, 6 = Fast, 5 = Medium, 4 = Slow, 3 = Very Slow, 2 = Incredibly Slow, 1 = 1/2 Slow, 0 = 1/10 Slow

     Incredibly Fast (8)= 2 × Very Fast (typically), available only to vessels with “Fast” in the descriptor
     Very Fast (7) = 3 × Medium (typically)
     Fast (6) = 2 × Medium (typically)
     Slow (4) = 1/2 Medium
     Very Slow (3) = 1/3 Medium
     Incredibly Slow (2) = 1/4 Medium
     1/4 Slow (1) = 1/8 Medium = 1/2 Incredibly Slow
     1/10 Slow (0) = 1/20 Medium – only when sailed/rowed into the wind (otherwise,s speed 0 in those conditions)

4.8.3.3 Functionality:

Draft:
There are 5 categories of Draft value. All come with both benefits and liabilities in terms of what a particular vessel is capable of.

In sci-fi terms, think of gravity wells as reefs, shoals, and distances to the coast – the stronger the local gravity well, the lower the “draft equivalent” that is needed. Having way-stations in orbit or on nearby planets / moons is the equivalent of deeper harbors, obviating the need to go into the deep, nasty, gravity well.

     1 Shallow (can use coastal waters, cross shoals & some reefs without danger)
     2 Near Shallow (can use coastal waters, cross most shoals & reefs without danger)
     3 Medium (can use coastal waters, cross deep shoals and reefs with little danger but shallow ones are a threat)
     4 Deep (can only use bays, cannot cross shoals or reefs without extreme risk)
     5 Very Deep (can only use ‘deep water’ bays at any time, needs high tide to use other bays, all shoals and reefs pose extreme risk)

Crew:
Crew numbers are specified as a range, minimum to maximum. Another significant value is 2x minimum. The numbers given are a base value that has to be adjusted for the number of officers and high-value passengers.

     Officers count as 3 crew but increase max crew by 1 each.

     Passengers in steerage / low-berths count as crew but NOT as minimum crew (Passengers who are in cold-sleep or something similar consume no rations and count only as dead weight, obviously).

     Passengers in high-berths count as officers but NOT as minimum crew.

There is also a “virtual crew count” used for the consumption of rations. For this purpose, officers may count as 1, 2, 3, 4, or even 5 crewmen. That doesn’t mean that they eat five times as much – but they may eat five times as well. Nor is this necessarily consistent amongst the entire officer corps – the captain, first mate, and high-berth passengers will often have one value while other officers are 1/2 or 1 less.

Crew Provisions

As per 3.1.1.13 & 3.1.1.14, the minimum requirement in food and water totals 5.25 kg/person per day. When you do the math, you get to a value of 0.0402 long tons × crew, per week. This number includes increased mess and galley size, which is one reason why Officers count as more extra crew than just their numbers. It does NOT include crew quarters, locker space, etc.

But it’s not that simple. When you’re crossing a desert, an arctic tundra, or out at sea, you can’t simply replace food that has spoiled – so you have to carry extra supplies just in case. How much in extra supplies is a function of paranoia and climate (things go bad more slowly in cold environments). I consider values of +10%, +25%, +33%, +50%, +75%, and +100%.

But that’s feeding people the minimum they need to survive – one minimal meal a day. Unless you had no choice but to impose such a regimen, crews would revolt at the imposition of such a regimen. So you also need to decide how many meals a day, and of what relative size (where that essential minimum =100%). I consider values of +10%, +25%, +33%, +50%, +75%, +100%, +150%, +200%, and +250%.

100%+250% means 350% total each day. How this gets broken up is irrelevant – there could be three light snacks and a feast, or one light snack and three solid meals, or whatever – so long as the grand total adds up to 350%.

When you correlate all these factors, you get the following table:

	spoilage allowance	+0%	+10%	+25%	+35%	+50%	+75%	+100%
better than minimum	+0%	0.04	0.044	0.05	0.054	0.06	0.07	0.08
	+10%	0.044	0.049	0.055	0.06	0.066	0.077	0.088
	+25%	0.05	0.055	0.063	0.068	0.075	0.088	0.101
	+33%	0.053	0.059	0.067	0.072	0.08	0.094	0.107
	+50%	0.06	0.066	0.075	0.081	0.09	0.106	0.121
	+100%	0.08	0.088	0.101	0.109	0.121	0.141	0.161
	+150%	0.101	0.111	0.126	0.136	0.151	0.176	0.201
	+200%	0.121	0.133	0.151	0.163	0.181	0.211	0.241
	+250%	0.141	0.155	0.176	0.19	0.211	0.246	0.281

For example: +35% spoilage allowance, +150% better than minimum, 16 crew: 0.136 × 16 per week = 2.176 long tons = 2.43712 short tons. If your ship has 50 long tons cargo capacity, you could carry provisions for those 16 and nothing else and have 20.5 weeks’ capacity. If you want to provision for a 6 week voyage, plus 2 weeks’ margin, it would reduce cargo capacity by 19.5 long tons. Note that for a journey of this short length, 35% spoilage is being really paranoid.

Ships owners will always look to cut unprofitable corners. Six weeks is short enough that even if there was 80% spoilage of the food, the crew could make it all the way to their destination without starving to death, and go even further if rations were cut in response to the emergency. What’s more, the crew can progressively eat their way through that extra two week’s worth, so you can cut the ‘better than minimum’ to +50% and still be feeding the crew reasonably well. That reduces the requirement from 0.136 per crew per week to just 0.06. This returns (0.136 – 0.06) × 16 × 8 = 9.728 long tons of cargo capacity to the pursuit of making profits – nearly 20% of the 50-ton capacity.

Cargo Capacity (short tons)
The numbers given are base values that need to be adjusted as follows:

     -1 cargo / 6 crew (or part thereof) over 2x min

     -0.5 cargo / cannon

At first glance, you might think that actual crew numbers should be used for these adjustments, but no, no, no – all crew and high-level officers have the capacity for personal baggage / comforts, and the highest ranking have even more of it. So use x3 for most crew & high-berth passengers and x5 for the cream – certainly that Captain, maybe the navigator, maybe the first mate, and maybe the doctor. Larger ships may further differentiate.

So total up the ‘effective’ crew numbers. If the result is less than double the minimum, they have not intruded into the cargo capacity; if the result is more than double that, but less than the maximum, then cargo capacity is reduced as shown; and if the total is more than the maximum, the ship is effectively overloaded and has NO spare cargo capacity.

If you cut rations, you cut the ‘effective crew’. I’ve made the assumption that we’re allocating 1016 kg / 5.25 kg per day × 3 = 580.6 meals per ton of capacity – and then applied a fudge factor to lift that to a neat 600, because a small overload will quickly disappear. Dividing that by 6 means that we’re effectively working in units of 100 meals – a nice, convenient number.

Some crew may require more or less nourishment than others. A Halfling would count as 1½ crew, for example. A Giant may count as 10 or more! Don’t forget to take such things into account.

Ships carry enough provisions for 2 × the minimum number of crew without intruding on the cargo space. But if your crew numbers exceed that quantity, you need to add extra provisions that won’t fit into the holds designated for the purpose.

Total Food Reserves

With the above information, you can quickly determine 2 × Min crew / 100 + the excess cargo calculated above to get a total provisions weight. Multiply the result by 100 meals in a long ton and divide by the number of crew determined previously (the count that factors in how well various people eat). The result is the number of days that the ship has provisions for – both food and water – if fully laden. This is often a useful number to know, to say the least, but because it varies according to so many factors, it’s not something that can be specified in advance – it needs to be recalculated for every trip, or sometimes for every leg of a trip.

4.8.3.4 Combat

Hit Dice / Hit Points:
     Potential HD = Class #

     Class 1-6 rafts = d2
     Class 1-6 Boats = d6
     Class 7-8 = -1 die, size to d8
     Class 9-20 = -2 die, size to d10
     Class 21-30 = -4 die, size to d12
     Class 31+ = -4 die, / 1.6 die, size to d20

     Reinforcement = – 2^(x-1) cargo where × is +1 defense & +1 HD.

     Actual HP = (Potential HP + Reinforcement) × Crew / Max Crew

Again, a note: If you only have 1/2 the maximum crew, you only have 1/2 the capacity for taking damage. That’s because you have fewer crew to replace the injured or killed, and fewer crew to work as damage control parties.

Damage
It doesn’t matter how damage is inflicted – it could be a cannon, a whole bunch of cannon, a fireball spell, a laser cutter, a beam weapon, or a whole bunch of rowdies with axes. This combat analogue measures Ship HP on the human scale, so all these things to whatever damage they would normally do.

Instead of rolling for each individual, if there are a lot of them, determine the roll required with all modifiers taken into account and translate that into a % successful.

Next, we need to apply a fudge factor. Divide the number of attackers by 6 (counting cannons as 6 attackers, fireballs as the number of d6 in the fireball, and so on). Roll that many dice and add the result to the % successful, then roll it again re-rolling all sixes and subtract the result from the adjusted % successful.

The more attackers there are, the less likely it is that there will be a significant variance. The ‘re-roll sixes’ is a deliberate abstraction to allow for the fact that sometimes a near miss is good enough.

Multiply the net % successful by the number of attackers, broken down by size of damage die if necessary, to get the number that actually hit – and them multiply by the average damage result, no need to roll it unless you want to do so for dramatic effect.

My Technique would be to actually roll the first wave of damage,. then apply average damage until the target vessel has less than 3 ‘salvos’ capacity remaining, then go back to rolling. This maximizes dramatic effect while minimizing inconvenience and inefficiency. Of course, if no PCs are involved, it’s average damage all the way – the ‘fudge factor’ provides enough randomness to seem realistically variable.

Damage Distribution:
     (3d20+40)% of damage is applied to crew. The rest is applied to the ship.

Crew Damage: Use half the indicated total damage to kill crew, based on average hit points etc. Apply the remainder as evenly as possible over the surviving crew (and note that this will reduce their average hit points for the next salvo).

Ship damage includes sail damage that slows the ship but doesn’t actually sink it, offensive damage that reduces a target’s ability to attack back, defensive damage that reduces a ship’s ability to stay intact, and hull damage that reduces it’s ability to stay afloat. So you may need to further break it down.

That breakdown depends on where the attackers were aiming which depends on what they were trying to accomplish. The attacker should nominate one of the four damage types indicated; this choice will persist until changed, and it takes 8 × minimum crew / surviving crew foregone attacks, round up, to make such a change (officers count as 3 as usual, due to their greater experience).

Example: Minimum crew is 20, current surviving crew is 65; it takes 8 × 20 / 65 = 2.46, rounds up to 3, attacks foregone to change targets.

The GM needs d6 in 4 different colors. One color represents sail damage, one offensive damage, one damages the targets’ defenses, and one hull damage. The GM needs 3 dice of the color that matches the chosen target of the attacker and 1 dice each of the other three, for a total of 6 dice (yes, there are ways of doing this will dice of only a single color – roll 1d6 three times and 3d6 once, recording the totals).

Divide the damage done by the total of the six dice (rounding off to the nearest 1/2) and then for each type of damage, multiply the result by the total of that colored dice. Round results in the opposite direction to any rounding that too place following the division.

Example: 1 red die (6), 1 green die (2), one black die (3), and 3 blue dice (10), total of 19. Damage done to the ship = 45. So, 45/19 = 2.368, which rounds to 2.5. Multiply the three dice total (10) by 2.5 to get 25 – that’s the number of dice of damage to whatever the attacker was targeting. Multiply the red die result (6) by 2.5 to get 15 – that’s the damage done to whatever the red die represented. The green die gives 5 points, the black die gives 7.5 – which gets rounded down to 7 because we rounded up to get to the 2.5.

Damage Effects
Divide the damage done to each area of effect (except hull damage) by 6, but record remainders as fractions of 6 – these can accumulate over multiple salvos / rounds.

Sail / Speed damage: it takes 6 points to drop from the vessels top speed rating by 1, then 5 to drop by another one, then 4, and so on, until the vessel reaches 0 and is dead in the water.

Defensive Damage: the result is the bonus that the attacker inflicting the damage will be at for their next attack. If the target vessel has enough excess crew to perform damage control, this will reduce by 1 on the attack after that, by another 1 on the attack after that, and so on. Damage control is limited to HALF the defensive damage done – the rest needs more time / resources than can be accommodated during battle. Furthermore, every -6 or part thereof has a 1 in 6 chance of becoming 1 worse during combat maneuvers.

Offensive Damage: this reduces the number of dice of damage that the attacked vessel can inflict on their next attack by the indicated number. If they have sufficient excess crew to work damage control, this will reduce by 1 on the attack after that, then by 1 more, and so on. Offensive damage repairs are limited to HALF the inflicted offensive damage, the rest can’t be fixed on the fly. Furthermore, for every -6 or part thereof, there is a 1 in 6 chance of doing an additional d6 damage to one of the other areas of the ship (roll a d3 to choose).

Hull Damage: The damage done comes off the ships hit points. If there are sufficient crew to work damage control, they can restore 1d6 points of hull damage in a combat round, and if they roll a six, they roll again and repair +6 points. Hull repairs are limited to HALF the inflicted damage, the rest can’t be repaired so easily. Furthermore, for every 6 points of hull damage done in a single attack after the first 6, there is a 1 in 6 chance of an extra d6 of hull damage resulting from combat maneuvers. Do enough hull damage to a target and it can literally tear itself apart, sending it to the bottom.

Furthermore, ships that lose 1/2 their HP in hull damage are slowed one additional Speed, and another when they lose 1/2 of what’s left, and a third when they reach 0.

Zero HP means that a ship is sinking. How long this takes is up to the GM but it’s usually measured in minutes for small ships and potentially hours for large ships. Or should that be seconds and minutes, respectively? The first is more historically accurate, the second ups the ante considerably. Ongoing Repairs / damage control may stem this. Each Ship-Class additional HP inflicted thereafter reduces this by 1 of the larger time units. So a class 9 vessel needs 9 additional HP of hull damage to hasten its’ sinking, a class 15 vessel needs 15, and so on.

Cannon
Cannon are divided into two classes for ‘ship vs ship’ battles: Light and Heavy.

‘Light’ means that each counts for only half the standard weight, but the cannonballs are lighter and smaller and do 1d6 per cannon per shot. Heavy means that each counts fully for the weight, the cannon have greater range, and they do d10 per cannon per shot.

Remember that cannon are usually arranged in pairs, one to each side of the ship, so at most half can fire in a given round.

An additional weight class, “Gargantuan”, is occasionally trotted out because they look really mean, but the cannon weigh twice as much as normal and only do d12, take twice as long to reload, and have no significant range advantage, so they actually have less effect than regular cannon.

4.8.3.5 Data Sources

A lot of research went into the above rules and the tables given below. Credit where it’s due:

Sid Meier’s Pirates! (Video Game, various incarnations)

★ Link 1

★ Link 2

★ Link 3

Wikipedia

★ Pinnace (ship’s boat)

★ Full-Rigged Pinnace

★ Sloop

★ Schooner

★ Lugger

★ Fluyt

★ East Indiaman

★ Brigantine

★ Brig

★ Frigate

★ Galleon

★ Clipper

★ Ship Of The Line

★ Spanish ship Nuestra Señora de la Santísima Trinidad

★ Ottoman ship Mahmudiye

Other (was actually used for the previous post):

★ Gouth AI a raft of 8 logs

4.8.3.6 Ship Specifications

This was originally one big table. At the last minute, I’ve broken it into three similarly-sized tables so that the headings are never too far away, and I’ve repeated the heading at the end of the third table for good measure. When this gets edited into an e-book, they might get rejoined or split into two, depending on how they fit on the page.

Class	Class Name	Len (ft)	Wt (lt)	Masts	Turn	Speed	Draft	Cargo Cap (st)	Crew	Cannon (Tot)
7	Pinnace*	28-40	100	1	1	5	Shallow	20	6-50	8
8	Small Sloop	45	140	1	2	5	Shallow	30	8-55	6
9	Medium Sloop	50	160	1	2	6	Near Shallow	40	10-65	10
10	Large Sloop	55	180	1	2	6	Near Shallow	50	12-75	12
11	Small Schooner	60	160	2	2	6	Medium	40	10-80	12
12	Medium Schooner	65	180	2	2	7	Medium	50	11-90	14
13	Large Schooner	70	220	3	2	7	Medium	60	14-100	18
(14)	Over-sized Schooner	75	240	4-6	3	6	Medium	70	18-140	22
15	Small Barque†	45	160	1	2	5	Medium	60	10-90	12
16	Medium Barque†	50	180	2-3	2	5	Deep	70	12-100	16
17	Large Barque†	60	200	3	4	4	Deep	85	16-120	20
18	Small Cargo Fluyt	50	160	2	4	3	Shallow	65	10-60	10
19	Medium Cargo Fluyt	80	200	2	4	3	Shallow	100	12-75	12
20	Large Cargo Fluyt	90	250	2	4	3	Shallow	140	16-85	14
(21)	Over-sized Cargo Fluyt	100	300	3	5	2	Near Shallow	180	20-100	16

 

Class	Class Name	Len (ft)	Wt (lt)	Masts	Turn	Speed	Draft	Cargo Cap (st)	Crew	Cannon (Tot)
22	Small Merchantman (East Indiaman)	150	185	3	5	5	Medium	90	12-90	14
23	Typical Merchantman (East Indiaman)	170	210	3	5	4	Deep	100	16-100	16
24	Large Merchantman (East Indiaman)	175	230	3	5	3	Deep	120	16-125	20
(25)	Over-Sized Merchantman (East Indiaman)‡	190	260	(4)	5	3	Very Deep	140	20-140	22
26	Small Brigantine†	50	50	2	4	5	Medium	60	12-110	20
27	Medium Brigantine†	110	110	2	4	5	Medium	65	14-115	22
28	Large Brigantine†	250	250	2	5	4	Medium	70	16-125	24
29	Large Brigantine (Brig)†	480	480	2	5	4	Medium	70	16-125	28
30	Light Frigate‡	120	800	3	6	3	Deep	60	12-140	28
31	Fast Frigate‡	150	1000	3	7	4	Deep	50	20-160	24
32	Frigate‡	135	1200	3	6	4	Deep	90	28-200	32
33	Heavy Frigate‡	140	1500	(4)	5	4-5	Very Deep	120	32-200	36

 

Class	Class Name	Len (ft)	Wt (lt)	Masts	Turn	Speed	Draft	Cargo Cap (st)	Crew	Cannon (Tot)
34	Light Galleon	100	500	4	4	3	Medium	70	12-140	20
35	Fast Galleon	120	1100	4	5	4	Deep	80	16-160	24
36	Medium Galleon	140	1000	5	4	3-4	Deep	120	16-100	20
37	Heavy Galleon	145	1600	5	3	4	Very Deep	140	16-200	32
38	War Galleon	150	2000	5	3	4	Very Deep	90	16-200	40
(39)	Over-sized Galleon	165	2500	5	3	4-5	Very Deep	120	24-250	44
(40)	Extreme Clipper‡	220	825	3	5	6	Medium	100	20-140	36
41	Standard Clipper‡	180-250	1080	3-(4)	5	6	Medium	100	20-140	38
42	Large Clipper‡	250-300	1410	3	4	6	Medium	120	20-140	44-60
43		(301-350)	1600	3-(4)	4	6	Medium	(125)	30-160	(50-70)
44		(351-400)	2000	(4)-(5)	4	6	Medium	(135)	40-180	(60-80)
43	Ship Of The Line (4th rate)‡	150	830	3-(4)-(5)	5	5	Very Deep	110	30-500	50-60
44	Ship Of The Line (3rd rate)‡	170	1440	3-(4)-(5)	6	5	Very Deep	115	40-600	62-74
45	Ship Of The Line (2nd rate)‡	200	2500	3-(4)-(5)	5	6	Very Deep	120	40-700	90-98
46	Ship Of The Line (1st rate)‡	250	4300	3-(4)-(5)	5	6	Very Deep	140	40-800	100-140
(47)	Imperial Ship Of The Line‡	200	5000	3-(4)-(5)	6	6	Very Deep	160	50-1050	116-148
(48)	Other??	GM’s Choice – see Exotic Crews, Below
Class	Class Name	Len (ft)	Wt (lt)	Masts	Turn	Speed	Draft	Cargo Cap (st)	Crew	Cannon (Tot)

* The term Pinnace was used for two entirely different but very similar vessels – the full-rigged Pinnace is the one used in the table as a vessel in it’s own right, while the Pinnace (Ship’s Boat) is only used in conjunction with a larger vessel (see ‡ below).

† There are two different types of ship that have been referred to as “Barques”. I have based these numbers on the “Lugger” class of vessel. Similarly, a “Brig” is a related vessel class to the normal “Brigantine” but is larger and heavier. This sort of nonsense makes researching vessel classes and their characteristics a real nightmare…

‡ Includes a ship’s boat; for an Imperial Ship Of The Line, this is a (medium) Sloop, for anything else it is either a Pinnace or, for ships >2000 long tons, a small Sloop. Note that Galleons had nothing but rowboats for service in this capacity, usually 16-man.

() denotes a configuration or vessel that did not exist in real life. For example, under “Masts”, you might see an entry 3-4-(5). This means that the real life versions had 3 or 4 masts but in a fantasy world, you might have 5.

4.8.4 Some Thoughts About Cannon

Maritime vessels place the GM in something of a quandary that these rules cannot avoid or evade looking at: Without cannon, an essential flavor of the swashbuckling expectations that come with these vessels is lost, causing dissatisfaction all round (no matter that it’s more ‘realistic’ and ‘historically accurate’).

But let them in, and you also let in everything else that gunpowder and cannonballs can do, and that can be an even higher price to pay. Cannon can pulverize castle walls. Grapeshot can wipe out whole battalions with a single salvo – from a handful of the devices. And some bright spark PC will want to create muskets and flintlocks, either personally or by paying someone else to do it. And then, there’s the issue of bombs, and of other explosive substances like nitrocellulose – once you’ve opened the door, everything from det cord to white phosphorous can crawl through it.

Some GMs are fine with all that, pointing out that in a world with Umpteen-d6 Fireballs and Meteor Swarms, a few cannon are really quite small potatoes, and that may be true – but again, some of the essential flavor is lost.

Some draw the line and say “this works, anything further doesn’t” – but they will sooner or later be met with the eternal challenge of the small child, “Why not?” – and he’d better have a good answer at the ready.

Others (including me, for a very long time), simply ban gunpowder and explosives outright. If you want a fusillade of cannon raking an enemy vessel, the equivalent in-game-world is an arcane spellcaster lobbing fireballs (etc) – you hire a bunch of them and they stand on the (lower) deck, casting through a ‘gunport’ (usually called something else, because you can’t use the word ‘gun’ before the gun exists). That’s just rubbing players noses in it.

But some of the research linked to above suggested that there may be a way….

4.8.4.1 Having Your Cannon And Your Flavor, Too

Specifically, it was mentioned somewhere that what is called a Cannon on land, and what is called a Cannon on board a seagoing vessel, are two completely different things. The land-going version is much smaller and lighter and uses a much smaller and lighter cannonball. They also use much less explosive propellant to launch those cannonballs. As a result of all this, they had about half the range of their larger seagoing versions. The basic reason for these differences is two-fold.

First, if your cannon is insufficiently-strongly anchored, a large part of your propellant force is simply going to launch it backwards, through your own troops.

And second, by the time you include frame and cannon and ammunition and black powder and everything else, it becomes too much to transport overland except on the very best roads. And a cannon without portability / mobility is worse than useless, 90% of the time.

Let us suppose, then, for the sake of argument, that Gunpowder works a little differently in the game world. In sufficient quantities, and ignited by sufficient heat, it will explode, right enough – but that requires either a mage or a fire elemental.

That means that your shipboard cannon are still perfectly fine, because it has long been established in most fantasy canon that arcane spells can be placed in scrolls that anyone can use. Now, that might be going too far, but if that’s the case, then it’s certainly not out of the question to compromise and state that a non-mage can use such a scroll, but doesn’t have the training to be able to set off gunpowder with it. THAT requires a ‘gunnery’ expertise.

This proposal doesn’t just permit the flavor of swashbuckling and pirates, it infuses them with the fantasy flavor that was supposedly being sacrificed!

It’s when you consider the implications outside of sea battles that this pays off, big-time.

4.8.4.2 Crippled Land-Cannon
Use enough gunpowder to set off an explosion under the above concept, and you will blow any normal land cannon to pieces.

There are ways around that – using Adamantine or something similar – but they increase the weight of the cannon to the equivalent of the too-big seagoing cannon anyway, and would cost an absolute fortune. There’s nothing that can be done to lighten the load because the cannon would no longer be strong enough to resist the explosive force within.

Or, you might throw a bone, and let smaller cannon and smaller gunpowder loads function – at 1/4 the normal power. While the results may be effective against enemy troops, they won’t do squat against castle walls. And the cannon is too big and inconvenient to carry around just for an antipersonnel weapon. Magic gives you far more potent and far more portable options.

4.8.4.3 Personal Firearms

Blunderbusses and Flintlocks go away, too – they fire not with a bang, but with a fsst. No bullets flying, which means that your Fighters are still supreme up close and personal, and aren’t going to be cut down (short of magic) before getting into position to absolutely ruin somebody’s day. And untrained nobodies aren’t running around stealing spellcaster thunder, either. Again the Fantasy within the Fantasy Genre is protected.

4.8.4.4 Bombs and other explosive devices

Bombs remain possible – but they need someone lobbing a fireball into exactly the right place, or a fire elemental charging into that right place, to set the device off. A wick or fuse won’t cut it. Again, the fantasy element is preserved, even enhanced.

4.8.4.5 Other explosive materials

And as for the rest of the canonical realm of explosives? The changes to the way gunpowder works should tell any player worth his table-space that the laws of chemistry are different. This should be obvious, anyway – alchemy can do things, and potions work, neither of which are true outside of the fantasy genre.

And that means that all the other panoply of explosive compounds and related materials that mankind has come up with, over the years, are also off the table. They simply won’t work. Soaking rags in nitric acid simply eats holes in the rags – it doesn’t create nitrocellulose.

Or maybe they will work – but only on the Elemental Plane of Water, or something – and they still need a fire elemental to set them off. Given the environmental complications, that’s sure to be more trouble than it’s worth.

So yes, you can have cannon on board ships, all you want, without sacrificing the important bits of the genre elsewhere. You are the GM, you decide the game physics, i.e. what will work and what won’t.

4.8.5 Exotic Crews

Section 3.1.1 gives you everything you need to be able to amend ship designs to create vessels built for non-human crews. In particular, the size factor and the proportions factor are your guide, but the specifics given in 3.1.1.10 will be just as useful.

If you have a crew that are somewhat smaller than human average, there are two routes that you can go – either you keep the vessel more-or-less the same physical dimensions and increase the crew capacity, then tweak the other values accordingly, or you scale the vessel down to fit.

If you have a crew that are somewhat larger, you have little choice but to scale the vessel up somewhat.

In both cases, at least one fundamental will change in terms of the shape – the height. Humans build decks to be about 2m apart, plus double the thickness of the deck itself, probably 2 × 2.5cm more, for a total of 2.05m. (That’s 6′ 8.7″ in American, and decking that’s 1″ thick). That’s built to accommodate relatively tall individuals of the era, and a fairly normal range of heights today.

4.8.5.1 Human Height Adjustments

It’s hard for the modern mind to come to grips with how much smaller people were back then, mostly due to malnutrition over multiple years during youth. Even the nobility didn’t eat as well, in terms of nutrition, as most poor people today.

The simplest way of adjusting modern height tables is simply to lop 6-12″ (15.24-30.48cm) off the indicated height – so 5’5″ becomes 4’5″ to 4’9″ (165cm becomes 134.52-149.76cm). Or, to simplify it, 65″ becomes 52-59″.

But that doesn’t really get precise enough for most people. My method of calculation isn’t as neat or as simple, but it gives more specific results. It’s based on nothing more than having visited a number of houses that were more than a century old and built proportionately to the inhabitants. That last is an important point; nobility and gentry and wealth tended to build high and impressive ceilings, so they are still high and impressive in modern times, just a little less so.

Modern			Medieval Nobles & Wealthy			Fantasy Professionals			Fantasy Poor
‘	“	cm	‘	“	cm	‘	“	cm	‘	“	cm
3	0	91.4	2	4	71.1	2	9	83.8	2	7.5	80
3	1	94	2	6	71.1	2	10	86.4	2	8.5	82.6
3	2	96.5	2	7.5	76.2	2	11	88.9	2	9.25	84.5
3	3	99.1	2	9	80	3	0	91.4	2	10.5	87.6
3	4	101.6	2	10.5	83.8	3	1	94	2	11.25	89.5
3	4.5	102.9	2	11.25	89.5	3	1.5	95.3	3	0	91.4
3	5	104.1	3	0	87.6	3	2	96.5	3	0.75	93.3
3	6	106.7	3	1.75	91.4	3	3	99.1	3	1.5	95.3
3	7	109.2	3	3.5	95.9	3	4	101.6	3	2.5	97.8
3	8	111.8	3	5.5	100.3	3	5	104.1	3	3.25	99.7
3	9	114.3	3	7	105.4	3	6	106.7	3	4.25	102.2
3	10	116.8	3	8.75	109.2	3	7	109.2	3	5	104.1
3	11	119.4	3	10.5	113.7	3	7.75	111.1	3	6	106.7
4	0	121.9	4	1	118.1	3	8.75	113.7	3	7	109.2
4	1	124.5	4	2	124.5	3	9.5	115.6	3	8	111.8
4	2	127	4	3	127	3	11	119.4	3	8.75	113.7
4	3	129.5	4	4	129.5	4	0	121.9	3	9.5	115.6
4	4	132.1	4	5	132.1	4	1.5	125.7	3	10.75	118.7
4	5	134.6	4	6	134.6	4	2.5	128.3	4	0	121.9
4	6	137.2	4	7	137.2	4	4	132.1	4	1	124.5
4	7	139.7	4	8	139.7	4	5	134.6	4	2	127
4	8	142.2	4	9	142.2	4	6	137.2	4	3	129.5
4	9	144.8	4	10	144.8	4	7	139.7	4	4	132.1
4	10	147.3	4	11	147.3	4	8.25	142.9	4	5.25	135.3
4	11	149.9	5	0	149.9	4	9.5	146.1	4	6.5	138.4
5	0	152.4	5	0.75	152.4	4	10.5	148.6	4	7.5	141
5	1	154.9	5	1.5	154.3	4	11.5	151.1	4	8	142.2
5	2	157.5	5	2.25	156.2	5	0	152.4	4	8.75	144.1
5	3	160	5	3.5	158.1	5	0.5	153.7	4	9.5	146.1
5	4	162.6	5	4	161.3	5	1	154.9	4	10	147.3
5	5	165.1	5	4.5	162.6	5	1.75	156.8	4	10.5	148.6
5	6	167.6	5	5	163.8	5	2.5	158.8	4	11	149.9
5	7	170.2	5	5.75	165.1	5	3.5	161.3	4	11.35	150.7
5	8	172.7	5	6.5	167	5	4	162.6	5	0.5	153.7
5	9	175.3	5	7.25	168.9	5	4.5	163.8	5	1	154.9
5	10	177.8	5	8	170.8	5	5	165.1	5	1.75	156.8
5	11	180.3	4	11	172.7	5	5.5	166.4	5	2.5	158.8
6	0	182.9	5	10.5	149.9	5	6	167.6	5	3	160
6	1	185.4	5	11.75	179.1	5	7	170.2	5	4	162.6
6	2	188	6	0.5	182.2	5	8	172.7	5	4.75	164.5
6	3	190.5	6	1.75	184.2	5	8.5	174	5	5.25	165.7
6	4	193	6	2	187.3	5	9.25	175.9	5	6	167.6
6	5	195.6	6	2.5	188	5	10	177.8	5	6.75	169.5
6	6	198.1	6	3	189.2	5	11	180.3	5	7	170.2
6	7	200.7	6	3.5	190.5	6	0	182.9	5	7.75	172.1
6	8	203.2	6	4	191.8	6	0.5	184.2	5	8.5	174
6	9	205.7	6	4.5	193	6	1.5	186.7	5	9.5	176.5
6	10	208.3	6	5	194.3	6	2.5	189.2	5	10	177.8
6	11	210.8	6	5.5	195.6	6	3.25	191.1	5	11	180.3
7	0	213.4	6	6	196.9	6	4	193	6	0	182.9

I realize it can be hard to see exactly what’s going on – the human mind doesn’t do well at assessing columns of numbers without analytic tools being employed. One such tool is graphical analysis, and so here’s one (with a couple of minor mistakes) that I prepared earlier:



This not only factors in nutritional effects, it incorporates nutritional requirements (higher for those with height) and social attitudes (it also takes into account that we’re operating in a heroic environment, in which people are bigger and better; for ‘real world’ numbers, lop another 4.5 inches off). Because of these additional factors, the ratios change a number of times as heights increase.

So, with a comparative yardstick, let’s begin.

4.8.5.2 Non-human Height

First, cargo capacity depends on two factors – volume and buoyancy. Volume is length × width × depth × shape factor. If the shape and proportions of the vessel are unchanged (at least for the moment), then the shape factors will cancel out, and everything will be adjusted proportional to the Height of the non-human species, proportionate to a 6′ modern human – i.e. a 5’10.5″ human (70.5″, 149.9 cm but I would use 150 for convenience).

EG: Let’s do a Halfling-scale merchantman. Length is usually 175 feet, Wt 230 long tons, cargo capacity 120 short tons, crew of 16-125, 20 cannon. 3 Masts, Turn 5, Speed 3, Draft Deep.

Halflings are about 3′ tall, so we need to reduce the height of our vessel to 91.4/150 = 0.60933 = 60.933% of normal. But our stats don’t mention height, or width for that matter; only the product of those – volume, and even that is implied only by assuming that the density of cargo and wood are the same.

If we’re going to reduce things proportionately, we need to multiply those values by the cube of our ratio – once for length, once for width, and once for depth.

     ★ 175 ft long × 0.60933 = 106.633 ft.

     ★ 230 long tons × 0.60933^3 = 230 × 0.2262376 = 52.034648 long tons.

     ★ Cargo capacity = 120 × 0.60933&3 = 120 × 0.2262376 = 27.1485 short tons.

# Cannon is a function of length, and has to be an even number.

# of Masts is also a function of length, but rounds down to any whole number, and has a minimum of 1. But you can round up if the answer is reasonably close to a whole number.

     ★ Canon: 20 × 0.60933 = 12.1866, rounds down to 12.

     ★ Masts: 3 × 0.60933 = 1.82799; close enough, call it 2.

4.8.5.3 Non-human Proportions

The crew have to be able to work. If the shoulder width relative to the height is the same as human, there’s no problem – but if the crew are slender, or broad-shouldered, that will affect both the horizontal dimensions of the vessel.

Halflings are often compared to human children, and children grow vertically a LOT more than they do horizontally.

8 year old boys average 50-52 inches in height (127-132 cm)*; our Halflings are 91.4cm tall max. Too much, let’s try lopping off the years one at a time.

     * Determined by asking Google for the “proportions of an 8-year-old boy”.

7 year old boys range from 45-53 inches in height (114-135 cm). Still too tall.

6 year old boys run from 43-50 inches with an average of 46 inches (117 cm). Still too big.

5-year-olds are typically 110-115 cm tall (3′ 9″) – still too big.

4-year-olds typically range from 37.5 and 43 inches – getting close but not quite there yet!

At 3 years old, the average human male height is 37.5 inches, about an inch-and-a-half too tall.

BUT WAIT: Those are all for children exposed to modern nutrition. We need to boost our 36-inch height to get a correct comparison!

     ★ 36 × 183 / 150 = 43.92 = 44 inches (3′ 8″ or 118.8cm).

Bang! Right away we’re back with 6-year-old boys.

Chest sizes for a 6-year-old are 23-24″ and waists are around 21″ – but we’re talking Halflings, so let’s set the latter to 25″.

     ★ 23.5 × 72 (adult height) / 46 (3-year-old height) = 36.78″.

     ★ 25 × 72 / 46 = 39.13″

Human Adult shoulders are an average of 18″ but anything from 15.8 to 20.9 is normal.

     ★ 39.13 / 18 = × 2.174 – so our Halflings are more than twice the size of a scaled human.

We need to apply that factor to length and breadth, and the square of it (4.726276) to anything ‘three-dimensional”: Or we can reduce the maximum number of crew by this number to make room for them. That seems the more sensible answer, so:

     ★ Max Crew = 125 / 2.174 = 57.5 – round up to 58.

4.8.5.4 Crew Strength

It might be that the ship Needs fewer crew, anyway. To find out, we need to scale the average human Lift by our original Halfling Factor and compare it to the average Halfling Lift value. We can absorb up to a × 2.174 ratio; beyond that, we either make the ship bigger (to take maximum advantage of the crew strength) or we have to again cut crew numbers. The danger of the latter is that we can’t let the number drop below the minimum of 16 indicated for operating this class of vessel.

     ★ Average Human Strength = 10, giving lift (maximum load) of 2 × 100 lb = 200 lb.

     ★ Average Halfling Strength = 8, giving lift (maximum load) of 2 × 80 lb = 160 lb.

     ★ 200 / 160 = × 1.25.

That’s no problem; in fact, it’s reasonable to reduce the minimum number of crew by this factor.

     ★ 16 / 1.25 = 12.8, round up to 13.

     ★ Total crew: 13-58.

4.8.5.5 Handling and other parameters

Masts, Weight, Length, Cargo, Crew. That sequence is important.

Using the ship tables, we need to find the vessel that most accurately matches our modified vessel, in that sequence. That in turn will give us speed, turn, and draft.

In this case, our needs are 2 masts, 52 long tons, 107 feet, 27 tons cargo, and 13-58 crew. Obviously, we’re going to be looking on the first table, and probably toward the top. Or are we?

Looking for a Masts match, I find:

     Small Schooner = Masts 2.
     Medium Schooner = Masts 2.
     Medium Barque = Masts 2.
     Small Cargo Fluyt = Masts 2.
     Medium Cargo Fluyt = Masts 2.
     Small Brigantine = Masts 2.
     Medium Brigantine = Masts 2.
     Large Brigantine = Masts 2.

So that’s my short list.

Vessel Weight of 52 eliminates most of these. I’m left with:

     Small Schooner 160 lt
     Small Barque 160 lt
     Small Fluyt 160 lt
     Small Brigantine 50 lt

I need search no further; it’s clear that the Halfling Merchantman will most closely resemble the Small Brigantine, in fact it’s not even close. Our length is twice that of the normal small Brigantine, so we’re going to be half as wide – and that shape is better at cutting through water, so we can add one to the Speed. All of which gives us:

     ★ Turn 4, Speed 6. Medium Draft

…compared to our staring values of Turn 5, Speed 4, Deep Draft. So the Halfling vessel is a little more maneuverable, a lot faster, and can operate in shallower waters.

4.8.6 Mixed Crews

There are multiple ways of handling this, but the best one is to ask, “who was this vessel designed for?”

If it’s a Frost Giant ship being crewed by humans, scale it up for frost giants. Next, look at the most common crew, or the closest to Frost Giants in size and strength (if you need to break ties). Work the numbers based on the abilities of that race relative to Frost Giants.

Then look at anyone not already accounted for. If they are larger / stronger than the reference race, they count as multiple ‘people’ for the purposes of crew requirements. If smaller, they count as a fraction of a crew for that purpose.

Which brings me to the end of this post, and the beginning of the next, which should finally bring this chapter of “Trade In Fantasy” to a close.

Running a campaign is a lot easier if there’s a clear process that maximizes opportunities for success and avoids the worst traps and pitfalls.

Campaign Mastery has again been recognized as one of the top 20 blogs devoted to the subject of RPGs. Given the caliber of the opposition, I consider this to be a significant compliment. Many thanks to FeedSpot for the acknowledgment and support! (Click the link to see where your other RPG blogs landed, or to look for new ones that may be of interest).

Inspiration

Today’s article was inspired by an article at EnWorld by Charles Dunwoody – a shout-out to him – entitled “Joyful GMing: RPG Success Strategies”. I adapted it into a flowchart to which I made a number of modifications, which you can read about in part 1of this two-part article.

The first part looked at the creation of a campaign, steps 1 through 5. Today, the focus is on running an ongoing campaign, and steps 6 through 10. To the side, I have repeated my modified flowchart, and – as you can see – step 6 has actually been subdivided into 5 sub-steps.

6. Adventure Creation

The central concept surrounding the sub-division of the original Step 6 is “Sandboxing In Time”. As the term itself makes clear, this is related to Sandboxing a campaign, but applies the concept to adventure creation and prep by breaking the process up into smaller steps. You’ll see what the advantages of this approach are in just a little while.

In traditional approaches, steps 6a through 6e are done in between sessions for the specific next adventure. Because the GM doesn’t know (or care) where the PCs will go and what they will get involved with in the course of that adventure and especially in its aftermath, he focuses all his attention on the immediate consequences of those decisions, only investing prep time in the very next adventure.

It assumes that the GM entrenches within each adventure several adventure seeds, far more than the PCs will actually have time to fully resolve in the next adventure; instead, they can either pick one or two, or even pick up on one or two that were left lingering in previous adventures.

It’s often a good idea simply to replace any plot threads seen through to a conclusion in the last adventure, so that the ‘pool’ of potential areas of focus remains constant in size, once the maximum desired pool-size is achieved – the pool doesn’t have to start fully-stocked.

For example:

Adventure #1 – four plot threads, two of which get resolved (player’s choice).
Adventure #2 – 4-2=2; + four plot threads = pool of 6, two of which get resolved.
Adventure #3 – 6-2=4, +2 new plot threads= pool of 6, two of which get resolved.
Adventure #4 – 6-2=4, +2 new plot threads= pool of 6, two of which get resolved.
Adventure #5 – 6-2=4, +2 new plot threads= pool of 6, two of which get resolved.
…And so on.

It can make life a lot easier for the GM if the ending of each adventure includes a mandatory statement of intent by the players on what they intend to focus on next time, but that rules out their choosing one of the new plot threads, which in turn permits them to be seeded somewhere other than the beginning of the day’s play.

That in turn gives the GM more flexibility in how he or she weaves them into the ongoing plotline and gives a less ritualized and more organic feeling to the whole campaign.

The biggest flaw to this approach is that no two adventures are alike in the scale of the prep required to bring them into a playable state. Some will be quick and easy, while others will by slow and convoluted; the process makes no allowance for this variation.

Getting around this problem isn’t all that difficult – you simply specify a fixed amount of time to be invested in prep on a regular basis that is sufficient to complete one of those slow-and-complicated development jobs, and – if the next adventure requires less – investing the remaining prep time in developing elements for future adventures, in effect investing that extra time in ‘getting ahead of the curve’, permitting the next ‘slow and complex’ prep to extend over multiple prep-sessions.

But this has an assumption (a big one) and carries a new flaw. The assumption is that you have correctly determined how much prep will be needed for the slowest / most difficult adventures and allowed enough time, OR have employed some corner-cutting within the process to cope with incomplete prep on game day.

You can assist that corner-cutting by a process of prioritizing what prep is needed most urgently to get the adventure under construction as close to ‘ready to play’ as you can get it within the available prep time. I like to also factor in how long the prep will take, and to differentiate between multiple standards of prep-and-polish – from ‘quick-and-dirty’ through to ‘extensive and polished’.

Links:

Prep Prioritization as a concept was first discussed in depth in Game Prep and the +N to Game Longevity, and was the core subject of Fire Fighting, Systems Analysis, and RPG Problem Solving Part 2 of 3: Prioritization and To Every Creator, An Optimum Budget?.

It would be remiss of me not to prominantly point to Creating Partial NPCs To Speed Game Prep before going any further.

The benefits of deliberately not doing certain kinds of prep get discussed thoroughly in Leaving Things Out: Negative Space in RPGs, while the impact of trying to do too much prep is the focus of Overcoming The GM Crash.

Two parts of the Basics For Beginners series, Basics For Beginners (and the over-experienced) Pt 7: Adventures and Basics For Beginners (and the over-experienced) Pt 3: Preparations take a lot of advice from my other articles and expand on it, including on this subject.

Finally, Dominoes and Daisy Chains: Writing Adventures has a lot of useful advice on all aspects of writing adventures, with links to relevant articles for further reading.

The flaw that this introduces is that you are actually violating the principle of sandboxing the campaign by working on material that may never be utilized, simply because if it is needed, it will take longer to prep than the time available.

Overcoming that flaw requires a more sophisticated approach to game prep than the ‘do everything for next session in between sessions’ approach, and organizing it demands a breakdown of the type that the flowchart proposes.

I’ll deal with those bigger-picture approaches in a set of sidebars at the end of step 6, but let’s start by looking at each step of the subdivided process and what it entails.

6a. Adventure Outline

An adventure outline is a summary of the central idea. It’s your answer to the question, “what’s the adventure about?”

It has to be short and succinct. A single line is preferable, or 2-3 sentences at most. Sometimes, that isn’t quite enough, but it’s a good standard to aim for. You can facilitate the avoidance of railroading within adventures by focusing your adventure outlines on what one or more NPCs are doing, rather than working from the point-of-view of the PCs.

As such, it shouldn’t have anything about how the PCs get involved, and should have little or nothing about how the adventure is to be resolved. That’s often harder than it seems, because the PCs should always be the focus and heart of the campaign. You achieve it by ensuring that whatever the NPCs are doing, it will have an impact on the lives of one or more PCs – in other words, the job of these outlines is to summarize how you are going to get the PCs into trouble and not how they are going to get back out of it.

6b. Adventure Draft

An adventure draft takes your one-or-two line summary of the adventure and breaks it down into major plot sequences, each of which is then summarized in one or two lines. In other words, they turn the idea into the outline of a story.

In theory, that’s all they contain. In practice, it’s never quite so simple – who the NPCs are, motivations for actions, ideas for locations and snatches of key dialogue and narrative always seem to get attached, and if you aren’t careful, you find yourself writing the whole adventure without having done the summary of the whole story first.

Now, some writers love that – the challenge of it, the discovery as you write of who the (NPC) characters are and what will happen next. Again, there is a very organic feeling to the result. But it’s also really easy to write yourself into a corner or a blind alley, and it’s then twice as hard to backtrack and choose a different path. The most sensible and logical path forward is the easiest and most natural to write, and that’s what got you into that mess to start with.

As a general principle, leave that sort of thing to the novelists; you need a more pragmatic, disciplined, and workmanlike approach. The best answer that I’ve found is a simple rule: Don’t connect ANY dots except in the draft outline, where you have that general breakdown of the action.

This, in turn, is best achieved through document structure, believe it or not.

Adventure outline.

Act 1 summary
Act 2 summary

     (space for more acts to be summarized)

Act 1 snippets / content

     (space for more details to be added)

Act 2 snippets / content

     (space for more details to be added)

Act X snippets / content

     (space for more details to be added)

The above is a generic and general demonstration, stripped of specifics. So far, 2 acts have been summarized, but there’s more to do before what you have is a story. In the course of summarizing them, some bits and pieces of these two acts have come to mind, and rather than trying to remember what they are, you’ve done the equivalent of jotting them down, with lots of white space in between. There has also been an idea recorded for content that hasn’t yet been tied to a specific act – this is usually something like the personality of the antagonist; you need to summarize it early so that it can be consistent with their actions in acts 1 and 2, but it hasn’t actually been revealed to the PCs yet. In fact, it might never be overtly spelt out except in the GM’s notes – letting the players form their own opinions (right or wrong) about the NPC’s persona.

Critically, no attempt to actually join the dots and spell out the full sequence of events in the acts is permitted until as many Acts as you need to resolve the story are outlined.

Once all the acts are summarized, you can then proceed to the next stage, breaking each down into specific plot sequences. You can then drop those snippets into place and connect those dots because you have a summary of the big picture to guide you and keep you out of those blind alleyways and corners.

There will be – well, there should be – lots of empty space in the document, even after you’ve broken the story down into plot sequences. Remember, at this point you don’t know what the outcome of those plot sequences is going to be; unless you’ve noted a specific description (or part of one), you have no specifics of locations, and so on. Instead you have a list of things that need to be created before the scenes can be completed.

The ultimate goal of this stage of the creation process is to have an end result that lets you completely improv the adventure while remaining consistent with the big picture. The level of detail needed to achieve this will vary from one GM to another, so each individual will need to set their own standards through a bit of trial and error.

There is also a significant difference between being able to completely improv around the general shape and being comfortable doing so. The first is the minimum standard to aim for, the second is the desired standard, but you don’t need to get there – yet.

6c. Supplemental Creation

From top to bottom, start to finish, fill the descriptive and narrative gaps, write up the NPCs to the extent that you need to (but no more), and so on. For example:

Location: Martian Domes

These are constructed of dozens of layers of gossamer silk exuded by martian worker-units, to which a stiffening agent has been added. In the primitive past, hundreds of layers were needed for strength, but the discovery of the stiffening agent permitted a construction boom. When the martians were forced into stasis because of the thinning atmosphere, dust and sand began to accumulate in the lee of the prevailing winds, so the domes appear more tear-drop shaped on planetary ordinance surveys. A relatively thin crust has slowly formed over the more exposed parts. The domes are variable in size according to function – worker-units and soldier-units are accommodated in the largest domes, 100-150 meters across, science, medical, engineering and colony management in intermediate domes 60-100 meters in size, and leader-units resided in the smallest domes, 30-60 meters in diameter. Several of the domes have collapsed over the centuries and filled with dust that has slowly fused into solid rock, but many remain intact. Archaeological testing will show that the domes were constructed at least 8,000 years ago, around the same time that humans started building pyramids.

Implications: organic feel to the technology, arachnoids, machines with multiple legs suitable for crossing difficult and dry terrain. Flat pads on the feet to cross sand. Hive-mind? Hierarchical society.

This description is generic enough that it can be the springboard for any specific dome’s description while supplying enough detail that other specifics can be detailed as needed.

What’s missing are numbers – how many of each dome? And, just possibly, an intermediate group that are more advanced than just workers – scientists and engineers and medical personnel.

Note in particular the ‘implications’ section, which plants the seeds for other things that might need to be described, producing a more even consistency of concept.

Next point: Quite often, one description will imply another, saving you the trouble of at least some of the detailed work.

Example:

Site Manager’s Office

The site manager’s office is spartan and pristine, at least on the surface. A bookshelf against one wall holds volumes on the design and construction of the site and its facilities, but these are organized in what appears a haphazard and unstructured manner. In reality, whenever one is consulted, it is returned to the top shelf, with others moving down to make room; over time, the references most frequently needed will congregate to that top shelf, while those needed less frequently get pushed down onto the lower shelves. Despite their having no purpose in a near-airless environment, rose-colored silk curtains hang in front of the windows, which (of course) cannot be opened. An artist’s depiction of the completed facility as it was originally envisaged hangs on the wall, capturing the design ethos of the facility in graphic form; it is far more structured and even than the reality visible beyond the curtains. The desk is large and constructed of a white plastic or ceramic material created with a combination of native martian materials and some admixtures brought from Earth. The chair is large, soft, and luxurious, with built-in leg and back massaging, designed for long periods of sitting. The only concession to individual flair is a perspex cube on the desk which contains an autographed baseball, it’s stitching slightly torn. Although the writing is faded and hard to read, it appears to have been signed by “Bub Ruth”.

Implications: Hard-nosed, pragmatic, organized to an extent beyond the obvious. Spartan but with dramatic touches and flourishes where they will be most noticeable by visitors.

After the description of his or her office, the site manager themselves needs very little description – it’s all spelt out or implied, already. Size, weight, race, gender, name – there’s no real hint about any of them, implying that these are secondary to the personality and the professional occupation.

The more two-birds-with-one-stone that you can incorporate like this, the less work you actually have to do in prep, and the more easily you can be consistent. Note that this description has two thrusts – practicality and the way the person is perceived by others. The latter could simply be vanity, but the first argues that it’s more deliberate and related to job function. There are further hints in the description of the office that the office-holder is organized and competent at their job, and a take-charge type who could be trusted to get the job done.

And yet, this isn’t quite enough to improv everything about the NPC – some things require further thought. Anything and everything related to their personality and their work performance are well-covered, but there isn’t enough there to tell us much about how their personal quarters are arranged or decorated. They could be along similarly spartan lines, or that might be a space in which the character can metaphorically let their hair down and relax. Which approach to take should be derived from their function in the story – are they to be hard-nosed and no-nonsense, or do they need a little softening to make them more rounded individuals?

6d. Revise / Polish Adventure

A lot of people skimp on this step, and there’s rarely a good justification for doing so. The technique and structures that I have described already are designed to keep the need for this step to a minimum, but that only makes failure to perform it all the more inexcusable.

What’s involved is fairly straightforward: Now that the supplemental creations are done, go back over the descriptions of events to transpire in the settings and the dialogue to be delivered and make sure that they are consistent with the descriptions of locations and NPC personalities.

Because the creation is holistic, with plot sequences inspiring content creation, most of the narratives will be fairly consistent with what’s already in place, but a quick once-over to be sure will usually reveal some areas that would benefit from the greater clarity of concept that you now have.

6e. Adventure Prep

If you feel the need to generate maps and diagrams and illustrations and photographic reference and anything else, this is when that happens. But that additional gloss is more often unnecessary than those of us who practice producing it regularly would like to think; it’s usually a secondary activity to the reality of Adventure Prep.

This stage is really about double-checking that the I’s have been dotted, the T’s crossed, and no unreasonable assumptions made; it’s a reminder of the content of the adventure (skim it only) and how it all fits into the bigger picture, and it’s about making sure that you are as ready to run the adventure as you possibly can be.

It’s also about making sure that all necessary resources are in the one spot so that nothing essential can be left behind (if you have to go somewhere else to game). The number of times I’ve seen someone forget to bring something they had spent hours preparing…. Okay, for any given GM running a game every weekend, it might only happen once a year, and often it’s not the end of the world (depending on what has been left behind), but still…!

6 Sidebar: Just-In-Time Adventure Creation

It’s a little more work in the campaign setting up process, but every time you start a new campaign, this bears thinking about.

Let’s say you have the breakdown of process that I have described above. And, when setting up the campaign, you generate 5 adventure outlines for adventures #1 to #5; and then you do rough drafts for adventures #1 to #4; and then you do all the supplemental creation for adventures #1 to #3; and then you do you final polish for adventures #1 and #2.

The results can be labeled ‘just in time adventure creation’, but it’s not necessarily obvious what’s happening unless you see it in a diagram – so I’ve done one.

What you end up with is a situation in which adventure #1, after some final prep, is ready to run.

Adventure #2 needs only that final prep to be ready to run.

Adventure #3 needs only to have final polish and prep to be ready to run.

Adventure #4 needs NPCs and Locations and narrative to be fleshed out, as well as final polish and prep, and

Adventure #5 needs everything except the generation of the final idea.

After running adventure #1, look at the breakdown of what happens if the GM carries out the same tasks listed above for the next adventure that needs that work to be done:
 
 
 
 
 
 

• He generates one adventure outline (for adventure #6);
• He turns one adventure outline into a rough draft (adventure #5);
• He does descriptions, NPCs, etc for one adventure that’s already in rough draft form (adventure #4);
• He polishes one adventure whose NPCs etc have already been done (adventure #3);
• He then does final prep and revision of the next adventure to be played (adventure #2),
• Leaving it ready to run, and everything else further up the pipeline one step closer to being ready to run.

In other words, he does no more between-sessions prep than usual once the campaign is underway, but has multiple adventures in progress.

Why is this such a big advantage? The answer is, flexibility.

If the GM has underestimated how long it will take to create NPCs etc for an adventure, he can spend the extra time by cutting out adventure first draft and maybe adventure outline, and has four game sessions to get caught back up.

Every adventure is still ready to run just in time; every adventure can be given final tweaks to accommodate decisions made by player agency; he has sacrificed a little extra time getting the campaign ready, buying himself insurance for a future occasion when he gets caught short of sufficient prep time for whatever reason. Real life gets in the way? No problem. Something takes longer than expected? No problem. An idea simply doesn’t work and needs to be scrapped or heavily revised? No problem.

Flexibility. When the time comes that you need it – and it happens to all of us – it’s priceless.

If you don’t have it, your only solution is to improv something with little guidance for how it will fit in and no regard for the bigger picture. With this arrangement, you always have some work done on the next adventure, so you always have the big picture perspective and something that’s at least semi-playable up your sleeve.

The key is in that final polish stage, now incorporating anything that you didn’t foresee in the way of player priorities or decisions, and making sure that the adventure as run always builds out from whatever the players have decided they want to do next session.

But there’s a secondary advantage as well: it makes foreshadowing a breeze. Hints and background events can be seeded into adventures with the deliberate intention of having them pay off in a specified adventure “not long from now”. This is something that the basic flowchart does really poorly, so that’s definitely something to contemplate.

6 Sidebar: A grander Vision

There are two other variations that are worth considering. The first is to develop adventure outlines for the whole campaign, or for the next six months of it at least. This essentially employs the same “general summary” technique used to turn adventure outlines into broad stories for the whole campaign or a significant slice of it.

If you have a look at the posts that I made here about planning what was at the time my next Dr Who campaign (it’s now ongoing) – links below – you can see an example of this process. I also used a similar approach to the Zener Gate campaign.

My superhero campaign goes a bit further – it has a long list of plot threads that are fully outlined, essentially mini-campaigns of 5 or 6 (or less, or more) adventures and employs a concordance to schedule “the next part” of each of these plot threads into specific adventures.

You still have complete flexibility to modify things, bring them forward, delay them, even abandon them altogether. Your adventures are still completely responsive to player input. But you get the sense of a much bigger campaign because there are multiple things happening all the time – and sometimes these can interact in interesting ways.

6 Sidebar: More epic adventures

Under this heading, i want to actually talk a little bit about the current adventure in the Doctor Who campaign because it shows flexibility being applied within the process described, and not just because of it.

I outlined the adventure in several acts, each representing a day’s play. The first act integrated the basic plotline with the character’s stated intentions and priorities so that events emerged naturally from his attempting to achieve those goals. A crashed spaceship on Skaro, the Dalek home-world, needed rescuing.

Act II was all about getting what the ship needed in order for that rescue to take place. It delivered the broader, more campaign-level developments that justified the story’s inclusion in the campaign.

Act III dealt with the actual rescue / escape and introduced a new villain, one who was ultimately responsible for the ship needing to be rescued in the first place.

This villain then blackmails the doctor into doing his dirty work in Act IV, which was mostly deep background material, but which included a first attempt at said dirty work.

Had the player not flubbed a major roll, damaging his lungs in a toxic atmosphere, breaking an arm and smashing his spacesuit, Act V would have completed the adventure, taking down an established villain and completing most of said villain’s backstory. This was the game session played this weekend just past.

Instead, he landed himself in hospital for a period of time while various parts of his anatomy were repaired and the session was about campaign backstory and planning how to complete the mission more successfully on a second attempt, which will comprise Act VI.

The function of the story within the campaign is to push the Daleks and Time Lords into the Time War. In fact, once the new villain showed his hand, it became clear that every possible choice by the PC led, eventually, to such a war; only the interval between cause and effect would vary.

But the heart of the campaign’s overall story isn’t about how the Time War began, it’s about the 8th Doctor becoming the 9th, a version of himself dedicated to fighting the Time War. Almost every adventure has seen a small step in that direction result from the titular PC being himself in the situations the adventures orchestrated. Its central tenet is that putting the character into the situations that comprised the campaign made this transition inevitable, whether the character recognized the slippery slope that he was on or not.

The new Act V was another step in that direction, as the character employs painfully-acquired skills in tactics and military planning to solve the immediate problem of completing the mission without stuffing it up a second time. But here’s the key point of relevance so far as this article is concerned: until the character blew what should have been a reasonably easy roll in Act IV, the Act V just played did not exist. It was completely written and researched in the two weeks between the Act IV and Act V game sessions and inserted into the adventure as a consequence of that failure.

It broadened the campaign canon in several areas, most notably in the history of the robotic dog companion of earlier Doctor Who and the history of an organization from those earlier days, a history that explained the situations depicted in later seasons of the TV show when both that robotic companion and the organization would reappear within the canon, integrating the campaign even more solidly with the established series canon from both before and after the supposed events of the campaign, and continued the overall story of the campaign – and none of it could have been planned in advance, because the character should have been able to make that roll – but didn’t.

In terms of the process outlined above, the entire adventure was developed to fit into the overall plotline of the campaign; it was ready to run without the inclusion of the new Act V. The only activity between game sessions that was anticipated was the final polish / prep, which is all about revising the adventure to incorporate the latest in-game developments surrounding the PC. Because of the failed roll, the new Act V became logically necessary, but it wasn’t simply shoehorned in – it was used to further the overall story contained within the campaign, as explained above, making both the adventure and the campaign better for its inclusion.

There are GMs who only run adventures-as-written, without adapting and evolving those adventures as play proceeds, just as there are those who insist on Rules-As-Written. They tend to be inexperienced, but that’s not a defining trait. The better you are at the art of GMing, the more you can integrate in-play events with the unplayed-as-yet parts of the adventure.

This anecdote shows, by example, how extensive the revision phase of the process described in the flowchart can be.

Admittedly, it’s a relatively extreme example – the only thing that would have been more extreme would have been the complete junking and replacement of the planned Act V (which became Act VI); that wasn’t necessary in this case. I wasn’t originally going to even mention it – this entire section wasn’t in my outline of the article – but, as I wrote the preceding sections, an impression seemed to be conveyed that the final stage was little more than a quick skim through the adventure to fix significant elements in the mind of the GM.

Most of the time, there’s not a lot more than that involved; but the system has the capacity to permit more substantial revisions when they are warranted, and this section is intended to highlight that.

7. Run Adventure

How long is an adventure? I’ve run D&D sessions in which the entire day’s play was consumed by a single room in a 5-room dungeon. The relationship between adventure breakup into acts and playing time is loose and slippery. As a general rule, I’ll try end end each act on a cliffhanger or a moment of decision or commitment, and I’ll try to drop a lesser cliffhanger part way through the adventure.

Because I have it to hand, let’s look at text length vs playing time from the current Dr Who adventure:

• Adventure Outline: 260 words
• Additional Background reference: 731 words
• Act I: 4524 words
• Act II: 4025 words
• Act III: 3179 words, 1 critical diagram
• Act IV: 4566 words (a lot of prepared dialogue)
• Act V: (newly inserted) 3615 words, and ran a half-hour short
• Act VI (was act V): 90 words (outline only) plus 1613 words that can be re-used from Act IV.

If I posit that the critical diagram showing the tactical progression of the escape from Skaro is worth the metaphoric ‘thousand words’, Act III contains 4179 words. If I extrapolate a full session’s play for Act V (3.5 hrs vs 3 hrs), that rises to 4217.5 words.

The average over the acts that have actually been played is therefore 4302.3 words. As a general rule, 4200-4500 words gets a solid day’s play.

As soon as you introduce a combat situation, the planning gets messier. As a general rule, most combat sequences get allocated 10 minutes plus 5 minutes per protagonist (PC or NPC ally) or significant antagonist. This gives one ‘qauntized unit’ of combat.

• Simple battles = 1 unit.
• Moderately-complicated battles = 2 units.
• Complicated battles = 3-4 units.
• Extremely complicated battles = 5+ units.

If the battle needs to be spread over multiple sessions, add one unit per extra game session to each session’s play to represent setting up and documenting positions and statuses.

Let’s take an example most readers won’t know: the Grand Finale of the first Zenith-3 campaign involved 5 acts, three of them battles of increasing complexity and difficulty, plus an aftermath of about 1/4 of a game session. There were 5 protagonist characters, +3 in the first, and +1 in the second; and each battle was with a single enemy. There was also about 2000 words worth of roleplay in between each battle. Acts I and II were set-up and totaled about 4700 words from memory (and ran slightly overlong).

Let’s work the math:

Act I + Act II: 4700 words
Act III: 2000 words + Battle #1:

One Battle Unit = 10 + 5 x (5+3) + 5 = 15 + 40 = 55 minutes
Complexity Level: Complicated = 3-4 units
     = 55 minutes x 3-4 = 165 – 220 minutes
At the lower end of this scale, so use 165 minutes.

Act IV: 2000 words + Battle #2:

One Battle Unit = 10 + 5 x (5+1) + 5 = 15+ 30 = 45 minutes
Complexity level: Complicated = 3-4 unites
     = 45 x 3-4 = 135 – 180 minutes
At the upper end of the scale, so use 180 minutes

Act V: 2000 words + Battle #3:

One Battle Unit = 10 + 5 x 5 + 5 = 15 + 25 = 40 minutes
Complexity Level Extreme = 5+ units
     = 5 x 40 = 200 minutes or more

Aftermath (also part of Act V, effectively): 25% of the game session.

If I arbitrarily set the average length of a game session to 4250 words, except for Act V which I knew would run a little long, so 4750 words, I can calculate backwards to determine how many words each battle unit represented:

Act III Battle #1: 4250-2000=2250; 3 units, so each = 750 words; 750 / 55 = 13.6364 words per combat minute in a unit.

Act IV Battle #2: 4250-2000=2250; 4 units, so each = 562.5 words; 562.5 / 45 = 12.5 words per combat minute in a unit.

Act V Battle #3: 4750 – 25% x 4250 = 4750 – 1062.5 = 3687.5; -2000 words = 1687.5 words; 5 units, so each is 337.5 words; 337.5 / 40 = 8.4375 words per combat minute in a unit, less if more than 5 units.

I wasn’t expecting a consistent value across all three battles; they were intended to be bigger stakes and increasingly frenetic. And Battle #3 was deliberately simplified to fit the available time – without that, the words per combat minute would have been closer to 10. It was the stakes that were bigger, not the combat complexity per se.

If I put those numbers onto a chart, I get the above. The red line is a straight line between the high value at 3 and the low at 5 simplified and shows just how consistent this is as a method of guesstimating how many words equivalent a combat is going to represent in a day’s play.

Extrapolating back, I get 2 = 16 words per combat minute and 1 = 17.5 words per combat minute. In other words, the less climactic / complicated the combat, the more room there is for the insertion of roleplay into the battle narrative. As things become insanely complicated, the need to clarify the tactical situation becomes all-consuming.

The other piece of wisdom that can be gleaned from the chart is some idea of the margin of error. The straight red line fits 3 of the 4 points almost perfectly, but it cuts the 4 mark at about 12 words per combat minute, while the actual value was closer to 12.5 – so 100 x 0.5 / 12 = &PlusMinus;4.17%. Call it &PlusMinus;5%, because there’s no indication that this is an extreme case.

It’s only a rule of thumb, but it’s a good one to have around.

8. End Campaign?

How do you decide that a campaign has reached it’s end? Well, if there’s an overarching story that connects the whole campaign together, that’s fairly obvious. If the campaign is more open-ended, it can be a more difficult question.

I can see 6 – no, 7 – reasons for a campaign to end in addition to Plot Completion (which I will include in the list for the sake of being complete):

• Plot Completion – the story is over. You might tell another story with the same characters in a sequel campaign.
• TPK – everybody dies. This doesn’t have to spell the end of a campaign if the GM/players don’t want it to; there are ways around it. New characters taking up where the old ones left off, some form of resurrection, some combination of the two, a sliding doors moment that rewrites history, whatever. Another option is to pivot to a new-character sequel campaign in which the world is living with the consequences of the previous PCs failure. So sometimes this ends a campaign and sometimes it doesn’t.
• Player Interest – the GM should always be on the lookout for the subtle signs of waning player interest, bearing in mind that everyone will experience this to a different degree and will express it to a different degree. If the signs are clear, though, maybe it’s time to wrap up the campaign and do something fresh.
• Player Departure – when a player leaves the campaign, that can be the end of things – it doesn’t matter why they have gone. If you know that the situation is only temporary, putting the campaign on hold for a while and doing something else might be a viable alternative. Several of my campaigns did not survive the death of one of the key players. Some of them did. One was put on hold for more than a decade. It happens.
• Character Limits – Some game systems limit how far the characters can advance. Those limits may or may not be sufficient to fully encompass the planned plotline of the campaign. Personally, I never let such limits constrain my campaigns – if they have to go into “epic levels” to get the story told, so be it. Other GMs feel very differently about the question.
• GM Interest – when prep becomes a millstone around your neck and you keep finding reasons to not do the things that you know you should, when the campaign becomes a grind, the GM has lost enough interest in running it that he is better off either putting it on hold while he recharges his batteries or shutting it down altogether. It can be said that you should always leave the audience – the players, in this case – wanting more. I disagree, I think you should always leave them satisfied.
• Internal baggage – sometimes campaigns grow so convoluted and complicated that internal baggage starts making plots harder to come up with. Again, when it becomes a grind, putting it on hold or shutting it down are viable options that have to be considered.
• Repetitiveness – when you’ve run out of original plot ideas and things start to feel repetitive, the campaign has run its course. Note that this can occur if PCs develop faster than the GM intended – when there are no credible threats left to challenge the PCs, and they win every fight without breaking a sweat, something has to change – and retiring the campaign is one option under the heading of ‘something’.

If the campaign is ending, you can let it quietly retire, or you can activate a planned ‘big finish’ of some sort. My co-GM and I already know how the Adventurer’s Club campaign will end, even if we don’t know when we will pull that trigger – and even if one of the other campaign-ending reasons forces our hand.

If the campaign is ending, then it’s back to ‘square one’ and the development of a new campaign. If not, it’s move on to step 9.

9. Revise Campaign

Too many GMs don’t do this, but after every adventure, the GM should revise his campaign plans, first to incorporate the direction in which the players want the campaign to travel in (and to avoid the directions in which they don’t want to go), and second because the characters will have evolved in the course of the last adventure and the GM should take that evolution into account, going forward.

This can take quite a bit of time and effort; the earlier it happens that the characters diverge from their anticipated path through the campaign, and the larger the campaign, the more significant the effort that is required.

Most of the time, it’s a lot more straightforward – so much so that GMs don’t see how critical it is. NEVER skimp on this step unless performing it would require shutting down the campaign for a period of time because the job is SO large.

When that is the case – for example, in my Zenith-3 (superhero) campaign – campaign revisions have to happen at the adventure outline stage. This complicates the adventures, but they tend to run for multiple game sessions – the current adventure has been running for a year of actual play (and been shut down for a year following my move).

That means that the overall campaign plan has to be robust enough to survive changes in direction and PC plans / goals / ambitions unscathed, while still letting those plans / goals be significant within the scope of individual adventures – and that’s a lot harder to pull off than it sounds. Plot Trains are inevitable in this situation unless you actively work to derail them – one of the limitations of the big sprawling campaign plan.

But either way, the campaign plan needs to be revisited and revised to accommodate the consequences of player agency. Whether it happens as a standalone step in the campaigning process (Step 9 as show) or gets folded into a more localized set of events / developments, it still has to happen.

10. Evolve Characters

The GM often doesn’t get to see how the key characters of the campaign – the PCs – are evolving until after it has happened, and there’s at least one game session lag between that evolution and the GM’s capacity to incorporate the evolution into the campaign; the evolved characters simply show up ready for play in an adventure that was written and prepped without knowing what they had become.

Inevitably, this makes the characters more capable and competent than the GM had anticipated, sometimes markedly so. The adventure as written will almost always seem easier than expected.

There are a number of potential solutions to this problem.

• Ignore it / live with it – my preferred option most of the time.
• Require player foreshadowing of evolution – I’ll discuss this below, it’s too complicated to put in a bullet-point.
• Anticipate character evolution and make the adventures harder to compensate for it – this is hard to get right, but very satisfying when you do. Beware of over-estimating how far the characters will evolve.
• Tweaking adventures on-the-fly to incorporate the evolution in the characters – sometimes, you have no choice but to do this, because the character evolution is adventure-wrecking; sometimes, you can get away with paying lip service to the changes at times and mostly going with the first answer offered in this list. If character evolution makes the planned adventure a walk in the park, it’s not always a good idea to prevent that. That’s answer #1 in its purest form.

Require foreshadowing of character evolution

In my Fumanor campaigns, whenever a character gained a level, I always required them to tell me what they intended their next character level to be.

Players were free to change their minds as the campaign played out – sometimes, a planned diversification down a character evolution side-path would be delayed or brought forward because the player felt that the change would better prepare the character for what they foresaw happening in the campaign.

This let me add little scenes here and there into an adventure showing the character trying to master certain skills or abilities that would lead to the planned evolution.

It gets a little more complicated when you don’t have the limitations of condensing evolution into a simple headline using character classes, but the general principle still works – foreshadowing what skills or abilities the player intends for the character to improve next is still possible.

When you are writing adventures, it can sometimes become obvious that characters are going to be pushed out of their comfort zone, and players may elect to evolve their characters in response to that eventuality – or they can decide that staying true to the character concept / personality requires them to accept that such situations will remain outside of their comfort zone. This also lets you anticipate and foreshadow such evolution.

So long as the decision is not binding until the character actually gets to evolve – i.e. gains a level or gets a certain amount of banked experience to spend – this can add greatly to the verisimilitude of the campaign.

My personal preference, when possible within the overall campaign plan, is to both foreshadow the next step in a character’s evolution AND let their last evolutionary development play some significant role in the next adventure, even if it’s only one small scene or a difference in the narrative that takes it into account without making a huge difference to the story.

These let the players sense that their character’s in-game experiences are being shaped by their evolutionary choices and implies that the campaign is evolving in response to their actions – in other words, they are a public demonstration of player agency, implying that other player choices are also having an impact, even if it’s not always obvious.

The rewards for making this little bit of extra effort are far in excess of the costs incurred in terms of GM time and prep.

Again, this all plays into the business of revising and polishing adventures; it’s another element within step 6e. Quite often, the only significant changes or additions to an adventure are a direct consequence or expression of character evolution.

The other thing that needs to be highlighted under this heading is that NPCs should evolve, too – either to further their goals / plans, or in response to in-game events that show a weakness or vulnerability or even an opportunity. Where PC evolution gets publicly displayed (a character exhibits a new ability), when an enemy gets to hear about this, they should revise both their own plans and their own future evolution to take it into account.

Back To 6a

I consider these post-adventure steps to be a permanent attachment to the act of running an adventure. When they are complete, the GM has them to employ as context within the campaign for their game prep – so it’s back to step 6a and the development of the next adventure.

Final advice

Prep requirements always expand to fill the available time plus 20% – or more. That’s just a reality that GMs have to get used to.

Ideally, prep can be spread out so that some of it gets done in advance. A number of scenes / adventures in the Zenith-3 campaign exist for no other reason than to introduce an NPC who will be a building-block for future adventures, or who will trigger the development of such building blocks.

The metagame benefit of doing so is that the character creation gets separated out from that NPCs campaign-significant appearance, making both that bit less work-intensive. On top of that, the GM gets to see what works and what doesn’t, and can fine-tune the character to make them more effective when it matters.

Campaign Activities: A sidebar

I have a little time up my sleeve, so I’m going to invest some of it in a sidebar at this point. Campaign events, from a meta-perspective, can be categorized as:

• Introducing new campaign elements – people, places, things
• Developing existing campaign elements and contexts
• Introducing new narrative threads / subplots
• Advancing existing narrative threads / subplots
• Interactions between existing and/or new narrative threads / subplots
• Concluding existing narrative threads / subplots

Six categories, in all. If a chart is drawn up showing the life of a complex campaign over time, the % of game content that each of these represents provides an interesting set of patterns over the lifetime of the campaign:

The image is a little hard to read, you can click on it to see a larger version in a new tab (so that you can switch back and forth between it and the text).

This chart breaks a campaign into 4 divisions – Early, Mid-campaign, Late, and End. Each of the first three is subdivided into three smaller periods the same size as End, to get 10 equal spacings and End is subdivided into two. In reality, there is virtually no chance that a campaign’s phases would be of the same duration, but the regularity helps with interpretation.

• At the start of the campaign, it’s divided 50-50 between introducing characters and introducing plotlines.
• 1/3 of the way through the early campaign, and these have shrunk to make room for advancing some of those existing plot threads and 5% in resolving early plot threads. This is necessary to give players a sense of accomplishment, of making progress.
• 2/3 of the way through the early campaign and 5% of the total is now devoted to developing existing campaign elements, while resolving plot threads is up to a little more than 10%. These take equal chunks out of the new campaign elements introductions and new plot threads – advancing existing plot threads remains consistent at about 15%.
• At the end of the early campaign, as it transitions to mid-campaign, plot resolutions remains about the same, developing existing characters and related campaign elements is up to about 10%, advancing existing plot threads is up to about 20%, and introducing new elements and plotlines continues to fall steadily to make room.
• 1/3 of the way through the mid-campaign, and a key characteristic of the mid-campaign is now a noteworthy component: interactions between plot threads. Advancing existing plot threads has again grown in significance, and plot resolutions have also grown. Steady falls in both new campaign elements and new plotlines continue in order to make room for these changes.
• 2/3 of the way through the mid-campaign is actually the half-way mark of the whole. Plotline resolutions and advancing existing plotlines have both grown as a share of the content while interactions and developing existing characters have remained about the same. The same steady reduction in new plots and campaign elements continues, now down to 20% each.
• As the campaign transitions from mid-campaign to late campaign, there are dramatic changes. Advancing plotlines grows again, and interactions between plot threads triple; there is actually a reduction in resolutions as a result, in addition to the steady drop in new content introduction. For the first time, advancing existing plotlines is SUBSTANTIALLY higher than new campaign content. This is a key feature of the late campaign.
• 1/3 of the way through the late campaign, and only 10% of the campaign is new character elements, and the same for new plotlines; advancing existing plotlines is now more than both of these combined. Developing existing campaign elements grows, and so does resolution of plotlines. In fact, more plotlines get resolved than get introduced.
• 2/3 of the way through the late campaign, and everything starts to come together in terms of narrative, resulting in a massive spike in plotline interactions. Character evolution becomes extremely important because that’s the trigger for subsequent plot developments. The big picture is starting to resolve itself into something definite. There’s neither an increase nor decrease in the emphasis placed on advancing plot threads outside of these interactions, and there’s another big drop in plot resolutions. Things begin to stack up on the PCs, in other words.
• The conclusion of the late campaign is the beginning of the End. Plot interactions collapse, because things have come together. Character evolution both results from the previous interactions and drives the next phase of the campaign. New campaign elements are almost non-existent, but there are a few new plotlines still being introduced – mostly in the form of short adventures of no campaign significance in between the more campaign-oriented material.
• Half-way through the End, there’s one final burst of thread interactions and the development of existing campaign elements. Advancing plotlines all but collapses because there are so few plotlines left outside of the main campaign plotline. Almost everything else has been resolved at this point, there’s only the Big Finish to come (and anything leading up to it).
• The End of the End is the end of the Campaign. There’s a little bit of interaction as all the existing plot threads coalesce into one plotline, there’s one or two isolated adventures to give that a little time in which to happen, there’s a tiny bit of plot advancement, and it all leads into the Big Finish. There’s also allowance made in the “New Plot threads” for an epilogue or even a prologue to a sequel campaign, building on anything not resolved. And, if you add up all the “New Narrative Threads”, 50 + 40 + 35 + 30 + 25 + 20 + 15 + 10 + 5 + 5 + 5 = 240; and the Resolutions add up to 5 + 12 + 12 + 18 + 22 + 20 + 25 + 10 + 20 + 45 + 85 = 394, it becomes apparent that the two aren’t to scale; there’s a significance factor in play. if resolutions are twice as important as new plotlines at the moment the latter are introduced to the campaign, 240 – (394 / 2) = 240 – 197 = 43, or roughly 18% of the campaign. If resolutions are even more important, this percentage only goes up. And those numbers assume that plot resolution is in the PCs’ favor – which might not be the case. Sometimes, a victory is simply stopping an explosion for long enough that it becomes somebody else’s problem.

Okay, where was I? Oh, yes.

The ideal of introducing everything before it becomes plot-significant can’t always be met. There will always need to be some measure of compromise and corner-cutting when it comes to prep. The goal is never for prep to be complete and comprehensive – fine detail takes a lot of time for often minimal gains – its to have the next adventure be ready to run effectively. If there’s time up your sleeve once that’s accomplished, you can spend it on incorporating fine details and nice-to-have adventure elements.

I try always to be aware of the best places to cut corners – juggling maximum gain in prep time for minimal impact on the adventure. This comes back to planning and scheduling campaign prep and the art of knowing what’s possible in the available time and what’s not – while keeping things loose enough that you can occasionally indulge yourself.

The campaign flowchart, and the process that it depicts, is an ideal, a guideline, something to be varied at need. This is especially true when it comes to adventure creation.

The closer to game play that you can leave the creation of an adventure, the better that adventure will be in terms of fitting into the existing and established continuity and context of the campaign – but the further from that point it takes place, the better an adventure will be in fitting into the overall campaign plotline and context. Both are necessary and desirable – and mutually contradictory.

There’s a saying in Computer Programming: “You can have it fast, you can have it cheap, or you can have it functional. Pick two.” Of course, that’s an oversimplification; these points define a three-dimensional solution space in which any point is a valid one to aim for. But it gets non-IT people thinking along the right lines, deciding what needs to get compromised and what can’t be – and identifying the costs associated with those specifications. If one function requested is going to be 70% of the development effort and associated expense, you have to at least think about whether or not that’s an essential, or just a ‘nice to have’ – is there some practical workaround that lets you do without it, slashing the development time and expense in the process?

This is a similar situation, the right answer is to compromise both just a little. But breaking the adventure development process up into discrete steps means that the compromise point can be adjusted within different phases of that process, maximizing bang-for-buck in terms of the development time invested by the GM.

There is no one right answer, there are innumerable wrong answers and even more poor ones. A campaign process that flows activities lets you ask the right questions and make the most effective plans for the utilization of your prep time. That reality is the best that you can realistically hope for, and its not to be sneezed at.

Starting and Running a campaign is a lot easier if there’s a clearly understood process that maximizes the opportunities for success and avoids the largest traps and pitfalls.

As usual, I worked on the next part of Trade In Fantasy until it became clear that it wasn’t quite going to be ready in time, then shifted gears. This article was originally intended to be the next time-out entry in the sequence, but it’s been preempted by the need to have something ready to publish in short order. In fact, it’s likely that I will have so much to say on the subject of today’s post that I will split it in two.

Inspiration

Today’s article was inspired by an article at EnWorld by Charles Dunwoody – a shout-out to him – entitled “Joyful GMing: RPG Success Strategies”. Overall, it seemed a solid enough article, if a little on the shallow end at times – but then, most blogs are, compared to the standards set for Campaign Mastery.

At it’s heart is a process for successful GMing which Charles polished and slip-streamed into a very simple workflow.

As I read the article, my first thought was that it really needed a flowchart to pull it all together, so I started to sketch one out, finding as I did so that I had something to say about each of the stages. The flowchart that you can see on the right was the result.

It’s nice, neat, and simple, and at the time, that was the full intention of this article – to supplement Charles’ article with my own advice.

But, as I started contemplating what that advice would be, part of it was that ‘this step really should be subdivided this way’ or ‘there’s something that’s been left out, here’. I found myself thinking, in the end, that the process may have been over-simplified, that there was room for some solid advice that would not fit the simpler structure.

Revision

So my first step was to revise the process and the flowchart by the inversion of steps 1 and 2 and the addition of steps 2a and 5a. Steps 9 and 10 followed, and then step 6 got subdivided into 5 sub-steps in a third wave of revisions. And, by now – as you can see to the left, the result didn’t look very much like the process described by Charles at all.

Make no mistake though – his original is still at the conceptual heart of things. I’ve just added a few things and complicated some others.

This flowchart is your road map to today’s article, your table of contents if you will. You don’t really need it to read and use the content, but it helps put the process into context.

I’m also going to do my best not to repeat Charles’ advice; his article is still relevant and it might even be useful to read it before continuing. So here’s that link again (opens in a new tab).

0. Start

Some people struggle with this step. A lack of confidence saps their willingness to accept the responsibility and workload. I can sympathize with that; there have been times when I was caught in a time-crunch by the real world and didn’t think I could spare the time / effort / creativity to run another campaign – and even had to put existing campaigns on hold, for a while.

But there’s a big difference between not having enough time and not having enough ability.

No GM starts with the complete skill-set that they need to run a successful campaign. It’s like a degree in computer science – from the moment the still-wet ink gets deposited on the page, your skills start to atrophy, and the world around you starts to evolve to date what you know. You can combat the first by actively using everything that’s relevant from what you’ve learned (and occasionally casting a refresher glance over the rest); to combat the second, you need to self-educate. Regularly and frequently, even constantly.

GMing is a little more forgiving, but when you are starting out, there will be mountains to climb. Fortunately, there are many sherpas out there to guide you, and none of the mountains is as forbidding as they seem.

It does help if your players have a similar level of experience to your own – they will be more forgiving of any lapses if they can’t do any better. It can also be helpful in the long run if your players are more experienced than you are – for a while, they may ride roughshod over your efforts (and that can be fun for them), but you will learn more quickly be being thrown in the deep end.

The biggest danger comes from having players with significantly less experience than you have – because they will be looking to you for guidance, and things can devolve into the blind leading the blind. Nevertheless, that is going to happen from time to time – and, when it does, your duty is clear: throw them in the deep end, but be prepared to guide them out if absolutely necessary. This sharpens their learning curve, just as experienced players do yours – but that only accelerates them getting ‘up to speed’. The one essential is for them to know that the GM has their back.

Of course, the time will come when you need to start loosening the apron-strings and letting the players sink or swim on their own. How much to pull back, and when, are as much a part of your campaign planning as anything else – or should be.

One technique that’s especially useful is to supplement the PCs with an NPC member of the team. This lets you speak to the players through that NPC, offering suggestions, demonstrating the right way to role-play, and so on. Don’t play this NPC as-written, at least at first; it’s a mouthpiece for you to use to get the PCs out of trouble, or headed in the right direction when they grow lost or confused. As the players become more experienced, you will naturally start adopting a harder line in terms of the character-as-written because the players will be less reliant on the outside input and advice. If you want to (there’s no real need), you can even mark ‘graduation day’ by killing off the NPC, symbolically telling the players “‘you’re on your own, now”.

One trap that I have seen multiple new (potential) GMs fall into is judging themselves by the standards set by more experienced GMs. I’ve lost track of the number of times someone has reached out to me to say “I thought I was ready to GM but I don’t understand half of the advice that you offer on Campaign Mastery” – I rarely write these articles for beginners; they are aimed at experienced GMs and poke into all sorts of nooks and crannies within the art. Some of the resulting advice will be useful to a particular GM, and some of it won’t be. My advice is always, bookmark anything that doesn’t make sense and come back to it a year or so later; eventually, your skills will grow to the point where you can make an informed and educated decision about the usefulness of what’s offered. Until then, if you don’t understand it, ignore it.

The same practice should be applied by beginner GMs to every experienced GM they encounter. Those experienced GMs will be able to do things that you can’t, and will do things that you might not – before you can take any lessons from them, you need to understand not only what they are doing, and how they are doing it, but why they are doing it. Only then can you judge whether or not it’s a practice that you should attempt to emulate. Don’t expect to run before you can crawl – design your campaigns and adventures with your own limitations in mind, while carefully pushing yourself to improve, and that’s all that anyone can ask or expect of you.

One final piece of advice before I move on – it’s okay to compromise on ideals and standards of GMing if you have to. Don’t expect to have all the answers, and do expect to have to diverge from your prepared plans when the players do something unexpected or expose a shortcoming in those plans. If you don’t have time to do everything that you would ideally like to do, have a plan B and execute it. If that compromises your prep, so be it. GM over-commitment is a mistake that we all make from time to time. It’s more important, most times, to deliver something playable than to dot every i and cross every t.

1. Campaign Concept

The campaign concept is the central idea at the heart of the campaign, painted in the broadest possible strokes. It focuses on what will make this campaign different from the one run by Joe Bloggs down the street. It’s the conceptual cornerstone that should inspire everything else.

As GMs grow in experience, they will often invert the sequence of Charles’ original steps 1 and 2 – they will have an idea for a campaign and then choose a game system that seems to suit it. Beginners tend to do it in the sequence he describes, in which they have a rules system and devise a campaign to fit into it.

The reason for the change is that the rules system inherently constrains the campaign concepts. If those constraints simply reinforce the intentions of the campaign, they are an advantage, not a liability; but when that isn’t the case, an alternative game system may be a better fit.

My first Fumanor campaign was designed and intended to be an AD&D campaign. The players persuaded me to make it a 2nd Ed campaign, but the differences between system and expectations grew until they became intolerable. So I converted it to Rolemaster, trying to put a little more grit into the mechanics. That didn’t work very well, and didn’t last very long. Finally, we adopted D&D 3.0 (and later, 3.5) and never looked back; it had the right balance between rules crunch and fantasy, between PCs and capabilities, at least for my taste. Your mileage, of course, may vary.

2. Choose Rules / 2a. House Rules

No rules system adapts perfectly to suit a campaign concept. There is, in modern times, a movement to running games with RAW – “Rules As Written”. I come from the old school, where if a rule didn’t work for any reason, changing it was not only acceptable but best practice.

I’m not going to dig into that particular debate; suffice it to say that both approaches have their benefits and their drawbacks. Instead, let’s talk about bad house rules for a minute.

Just because you can change something, doesn’t mean that you should. Yes, a revised rule might better implement your vision of the campaign, but that alone isn’t always enough to justify changing it; the rest fall into the category of other consequences. Before you can change a rule, you need to understand why the rule is as it appears, and why it will be advantageous to change it, and whether or not there are alternatives to consider, and what the ramifications and consequences outside of the purpose of the change are going to be. Only then can you determine whether or not the price is worth paying.

In the bad old days, GMs rarely made such detailed assessments. “I want X” was justification enough – and, as a result, some truly appalling rules were foisted onto players and campaigns.

Sometimes, even doing all that analysis isn’t enough – see the Woes Of Piety & Magic article published way back when under the heading of Greatest GMing Mistakes. In the case of the Piety system, the intentions were both noble and respectable, and the implementation seemed like a good idea at the time. Suffice it to say that it bogged everything down, it broke game balance, and it didn’t achieve it’s intended goals.

Not all house rules are like that. Most fall into two categories: rules that cover areas that the RAW overlooked, and rules that change the way the RAW function within the campaign context. The first are always easier to justify than the latter, but both have their place.

I remain perfectly happy to change the rules if I deem the change necessary. I’m just a little more cautious about what changes I make. They exist to better fit the game system to the campaign, and to patch holes in the RAW.

3. Campaign Overview

A campaign overview is a brief synopsis of what is going to make the campaign different / unique. It’s a hook, a broad breakdown of the how the central concepts of the campaign will be introduced to the players and how they will make a difference to the story of the campaign. It’s the bait with which you lure potential players into playing it.

In effect, it is a summary of what you expect to occur within the campaign, in general terms.

Every house rule that doesn’t simply patch a hole or problem within the game mechanics needs to be highlighted in the campaign overview – there needs to be an element of the campaign that does nothing but bring the central tenets of the campaign to the players’ attention and show how they will impact the overall story.

A lot of GMs skip the campaign overview stage, and that’s never a good idea. Even where you expect the campaign to be responsive to player choices and demands, you need an overview to place what the players want to do into context, and to restrict players choices where they do not fit the campaign concept.

There are two basic approaches to campaign overviews: the PC-driven and the Existential.

In a PC-driven overview, the GM is committing to arranging in-campaign circumstances that will force or require the PCs to achieve certain things, which will mitigate or undo those circumstances. This forces them to earn their player agency, starting with small amounts at the beginning of the campaign and ending with near-total agency at the end. This type of structure works very well when PCs present at the table with goals or motivations spelt out, as for example in a superhero campaign. All the GM has to do is find a way to conflate each PC’s goals with the bigger campaign picture.

My superhero campaign is a PC-driven one; there are multiple plot threads running concurrently. At least one, and often several, for each PC, at least one for some significant NPCs that will affect the PCs, at least one that will reshape / is reshaping the campaign world, at least one for a major organization, and even a couple that revolve around enemies of the group. Not all of these advance at once; everything is geared at building to a crescendo – in 10-15 years. My Dr Who campaign is another example.

In an Existential campaign, the PCs don’t even get mentioned in the campaign overview; instead, it’s all about the world around them and how it is going to change (unless, perhaps, something is done to stop this from happening). These events provide context and boundaries for whatever the players want to do; there is no expectation that the PCs will solve all the world’s problems, only that they will seek to survive and advance themselves in the face of whatever challenges get thrown in their way.

The Adventurer’s Club campaign is an existential one. We know how we have reshaped world history, we know how we have reshaped the world history that is yet to unfold, and we know how that will affect the parent and titular name of the organization to which the PCs belong. Those things all happen in the background, occasionally providing flavor and context, but generally not playing a pivotal role in the adventures themselves, which tend to be more standalone affairs.

Both approaches work; the key difference lies in what the GM expects from PCs in the campaign, and hence what they expect from players. This has to be spelt out in no uncertain terms as part of the initial briefing for potential players.

4. Attract Players

There are three ways of grouping potential players – open, closed, and a hybrid of the two.

The Open approach means that there are lots of potential players out there and you only have to make the existence of the forthcoming campaign known to attract some of them. Advertising a campaign on a University noticeboard or a Facebook group, for example, or at a games store.

The Closed approach means that you already have contact with a group of players and are trying to devise a campaign that will appeal to them.

The Hybrid approach means that there are one or two specific pre-selected players that you want to satisfy / attract, but that you are openly advertising for others to adventure alongside them.

There are significant ramifications to the different options. The closed and hybrid approach mean that if your campaign concept doesn’t appeal, you have to set it aside and start over. The friends with whom I game have no interest in a Star Trek -based RPG for example, and only one of them is really into Doctor Who. But I could count on at least two of them and maybe three or all four if I came up with a Babylon-5 based campaign. The structure and content of the campaign are dictated by the preferences of the players.

An open campaign, on the other hand, operates on the “Build It And They Will Come” principle. Your proposed campaign might only appeal to 1 in 1000 gamers, but you only need 3-5 of them – so if there are 3-5,000 players who learn of it’s proposed existence, all will be well. The more popular your campaign concept is, i.e. the broader its appeal, the more easily you will attract players – and the more of them you may have to turn away for lack of space.

When do you propose playing? The majority of my games happen on a Saturday because that’s when people are neither working nor studying. I used to belong to another group that gathered on Friday Nights and the occasional long weekend. I know of two groups – one meeting on a Friday and one on a Tuesday – because that’s when the players are available. I used to run regular but occasional games on Sundays as supplementary to the Saturday game sessions.

With a closed or hybrid model, you are already constrained in terms of when, but you probably already know what those restrictions are. Players joining up will have to be available at times that suit. With the open and hybrid models, any restriction of time also restricts the compatibility of possible players and campaign. Pick an unpopular day and time because it suits you and you may find that you attract no player interest.

Picking a popular time can also be problematic, as potential players are more likely to already have a game to go to!

Ultimately, attracting players is an exercise in Marketing. That means that there are a number of stages to the process, and you need a plan for each of them. These are: Awareness, Appeal, T’s & Cs, and Responsiveness.

Awareness: Before someone can consider becoming a player in the proposed campaign, they need to know that it exists. The more places you advertise its existence, the broader the potential pool of players – but the better you focus you advertising presence, the less effort you will waste on those who will never be interested. For about $5 a week, I can sponsor a radio show on local community radio; this produces advertising that will reach thousands upon thousands of listeners – but most of them won’t be gamers. Placing an advert on a noticeboard at my local library will only be seen by a few hundred people, but there will be a slightly higher response rate because there’s already a gaming group that meets there regularly. Placing an advert on a noticeboard at the local games store may also only be seen by a few hundred people a week – but they will all be gamers, and they will all know other gamers.

Appeal: Once a gamer knows that the campaign exists, the next thing that has to happen is that it has to appeal to them. That means describing it in an accurate but appealing way and in a way that can be comprehended in a very short space of time. People don’t have time to, and won’t, read an entire paragraph. You’re lucky if you can get them to read a full sentence and not a sound bite. My best advice: think like a spammer. Yeah, you heard me right. Construct a clickbait headline that will attract people strongly enough that they will then read a slightly longer descriptive passage of the proposed campaign. I would also direct your attention to the Secrets Of Stylish Narrative series, which is all about compressing text to make it shorter and more comprehensible while not skimping on the flavor. And practice – lots of practice.

T’s & C’s: I don’t know if this term has gone as viral in advertising elsewhere as it has here in Australia. It stands for “Terms and Conditions” – but only takes half as long to say, and is generally something that people can figure out from context even if they’ve never heard it before. In terms of your advertising for players, it means specifying where and when play is proposed, and what level of flexibility there is. There may be other restrictions like “No Power Gamers”, or “University students / graduates preferred”. Finally, a content guideline is probably appropriate – “G” or “NRC” or “Mature Concepts” or even “Occasionally Explicit Language Tolerated”. The goal is to avoid wasting your time and the time of a prospective player.

Responsiveness: Finally, a call to action – while making that action as easy as possible for the prospective player to complete. You don’t have to go as far as “Scan this QR Code to phone the GM” – but the easier it is to respond, the better. But there is a downside – this information is going to be open to the public, and that means open to potential abuse. I don’t know that you need to go as far as a burner phone, but using a disposable email address might prevent a LOT of grief.

5. Character Generation

So you’ve attracted a group of players who are willing to at least give the campaign a go. If you’re exceedingly lucky, you may even have a standby list to back them up. You’ve gathered them together for the purposes of character generation. Which means they need a more extensive campaign briefing in order to make good choices for their characters. I’m a big believer in collaborative concept selection – for example, when generating characters for the Zenith-3 campaign, I specified six or seven broad categories of PC archetype – the equivalent of character classes & race – and let the players choose in sequence of them signing up for the campaign. That didn’t prohibit two of them choosing the same thing, but it encouraged them to pick a slot that hadn’t been filled on the team – and, since there were more slots than players, they collectively decided what parts of the campaign they were going to find more challenging.

There are two different approaches to character generation – all together, or individually / piecemeal. “All together” means everyone at the same time and the same place. “Individually / piecemeal” means one-on-one sessions with the GM. The second is more realistic in that the PCs will have no knowledge of each other; the first ensures that there are no secrets between the PCs.

Under certain circumstances, there is also a lot to commend in adopting a hybrid approach – a trusted, pre-selected, player who knows both the game system and your campaign style can be a lifesaver if the other players don’t know the rules, acting as an assistant GM. But you need to be able to trust them implicitly because they will be generating their PC separately from the others.

The other big advantage of the “all together” approach is that it turns the character generation process into a social occasion. You should play into this, especially if there are players that don’t know each other already.

The GM needs to be on-hand during character generation to answer questions. And, if you are taking the “all together” approach, they should also observe the emerging group dynamic closely. What are the rough spots? Who gets along immediately? How are these personal dynamics likely to affect the way the PCs interact in-game? Are there any red flags that suggest someone may not last as a player in the campaign? Or any black flags that suggest you might need to actually expel someone from the group?

It’s far too early at this point to make any such decisions, but it’s never too early to start watching out for potential unpleasant surprises.

5a. Player Commitment

Another subject that requires thought in advance of the first session – even if that’s only for the purposes of character generation – is an answer to the question “What are you asking the players to commit to?” and the related question, “What are you committing to?”

I ask new players to commit to playing 2-3 sessions before pulling out if they don’t enjoy it, and to give me at least one session’s notice that they will be doing so. At the same time, only a fool doesn’t recognize that circumstances can change, and novices may not have any idea of what sort of time commitments they are actually signing up for. If you expect players to do something in between game sessions, that needs to be spelt out, as well. I commit to giving players a little latitude to modify or tweak their characters for the first few game sessions. I require all players to be friendly toward each other and myself, and to telephone (preferably a day in advance) if for some reason they can’t attend – and commit to making allowances for genuine emergencies and general ill-health.

Some groups have an expectation that they will go together to buy lunch / dinner; others have social contracts like ‘phones off during play’. Some groups demand that people take it in turns to buy drinks or snacks for the group, or that everyone will pitch in to help clean up afterwards.

I know at least one group that permits no-one but the GM to crack open a rulebook other than the player’s book at the game table during play and another that won’t even permit that much.

The variety if social contract that can be found in an RPG group are incredible. As a general rule of thumb, these things are only problems if they aren’t clearly communicated to the participants. That communication is your responsibility, as is the leading of any discussion of what the social contract terms should be within the group.

And with that, I’m about half-way through, and right out of time. To be continued….

Today’s post focuses on Rafts and small boats like Kayaks and Canoes. The defining trait of such vessels is that while they can have sails, their primary motive power derives from the use of oars or paddles.

It’s taken quite a bit longer than I intended, due to a fundamental truism of publishing, at least to Campaign Mastery: Tables Take Time – and this post needed 9,877 lines of hand-coded HTML tables, completely on top of the effort needed to generate the content of those tables.

Even now, I’m more than a little concerned that Table 3 has too many columns and may need to be split in two – a task that there is not enough time to complete prior to deadline. But we’ll see how we go – if you’re reading these words, then all is well; if I’ve had to rewrite them, you’ll be reading about that, instead!

Table Of Contents: In part one of this chapter:

Chapter 4: Modes Of Transport

4.0 A Word about Routes

4.0.1 Baseline Model
4.0.2 Relative Sizes
4.0.3 Competitors
4.0.4 Terrain I
4.0.5 Terrain II
4.0.6 Multi-paths and Choke Points

4.0.6.1 Sidebar: Projection Of Military Force

4.0.7 Mode Of Transport

4.1 Backpack / Litters / Shanks Pony

4.1.1 Capacity
4.1.2 Personalities / Roleplay

4.2 Horseback

4.2.1 Capacity
4.2.2 Requirements
4.2.3 Personalities / Roleplay

4.3 Mule Train

4.3.1 Capacity
4.3.2 Requirements
4.3.3 Personalities / Roleplay

4.4 Wagons

4.4.1 Capacity
4.4.2 Requirements
4.4.3 Other Exceptions – Animal Size

4.4.3.1 Sidebar: Road Trains

4.4.4 Fodder / Food & Water Needs

4.4.4.1 People
4.4.4.2 Horses
4.4.4.3 Mules
4.4.4.4 Oxen / Cattle
4.4.4.5 Elephants
4.4.4.6 Other

4.4.5 Personalities / Roleplay

In Part 2:

4.5 River Boats & Barges

4.5.0 A Splice Of Maritime History

4.5.0.1 Dugouts & Canoes
4.5.0.2 Rafts
4.5.0.3 Boats
4.5.0.4 Poled Rafts & Barges
4.5.0.5 Oars
4.5.0.6 Land-based motive power
4.5.0.7 Sail
4.5.0.8 Better Sails
4.5.0.9 Trading Ships
4.5.0.10 Warships & Pirates
4.5.0.11 Beyond the age of sail
4.5.0.12 Riverboats
4.5.0.13 Sources

4.5.1 Riverboat Capacity
4.5.2 Favorable Winds

4.5.2.1 The Beaufort Wind Scale

4.5.3 Favorable Currents
4.5.4 Unfavorable Winds / Currents – Oarsmen Requirements
4.5.5 Unfavorable Winds / Currents – Sail Solutions
4.5.6 Extreme Weather Events
4.5.7 The Tempest Scale
4.5.8 Vessel Rating
4.5.9 Weather Cataclysms

In today’s post:

4.6 Rafts

4.6.1 Rowing Time & Exhaustion
4.6.2 The basics of vector sums

4.6.2.1 An Example
4.6.2.2 A better example
4.6.2.3 With Maths
4.6.2.4 Simplified Vector Sums
4.6.2.5 Multi-hour Vector Sums


4.6.3 Raft Design & Operation

4.6.3.1 Buoyancy
4.6.3.2 Raft Calculation Process
4.6.3.3 Why all this matters
4.6.3.4 Category 1 Raft Table
4.6.3.5 Category 2 Raft Table
4.6.3.6 Category 3 Raft Table
4.6.3.7 Category 4 Raft Tables
4.6.3.8 Category 5 Raft Tables
4.6.3.9 Category 6 Raft Tables


4.6.4 Overloaded Rafts
4.6.5 Raft Breakup
4.6.6 Construction Time
4.6.7 A final word on Overloading Capacities

4.7 Canoes etc

4.7.1 Proportions
4.7.2 Frontal Dimension
4.7.3 Base Speed

And next:

4.8 Seagoing Vessels

4.8.1 Capacity
4.8.2 Favorable Winds
4.8.3 Favorable Currents
4.8.4 Unfavorable Winds / Currents – Oarsmen Requirements
4.8.5 Unfavorable Winds / Currents – Sail Solutions
4.8.6 Extreme Weather Events
4.8.7 Vessel Rating
4.8.8 Weather Cataclysms

4.9 Exotic Modes Of Transport

4.9.1 Flight
4.9.2 Teleport
4.9.3 Magic Gates & Portals
4.9.4 Capacities

In future chapters:

5. Land Transport
6. Waterborne Transport
7. Spoilage
8. Key Personnel
9. The Journey
10. Arrival
11. Journey’s End
12. Adventures En Route

4.6 Rafts

So far as this system is concerned, vessels come in three main types – rafts,. canoes & rowboats, and ships. Further, canoes and the like can be treated as a special sub-type of Raft, enabling a common set of rules for the definition of their traits and characteristics.
.
For this reason, Canoes and any other form of vessel whose primary motive power comes from oars or poles, are considered a sub-variety of rafts, though I have separated them out into a small section of their own.

I have to stress that these are not the pleasure-rafts that many people grew up with. These are rafts designed and assembled to be able to handle sea travel. They have to be sturdier, heavier, and better built than the home craft created by lashing a few branches together. There will be some overlap but it won’t be as great as you might think.

It should also be pointed out that a raft of 10 square meters or more is enormous! In modern times, we’re used to thinking of large life rafts of this size that can hold anywhere from fifty to a couple of hundred people while they await rescue; the larger end of this range of rafts are of comparable size, but made of timber, not inflated plastic. That makes a pretty huge difference. So much so that it’s fair to expect the upper end of these craft to only exist in a fantasy world.

4.6.1 Rowing Time & Exhaustion

Crews can row for 2 hrs maximum before resting for at least 1 hour.

If need be, a tired crew can continue for another hour, but will only achieve 3/4 of their normal speed. This hour also has to then be added on to their recovery time, which increases to two hours.

A further hour at 1/2 speed then becomes possible, but this ads 2 more hours to the recovery time.

An exhausted crew can manage one last hour at 1/4 speed, at the price of needing +2 more hours recovery.

It can be helpful to visualize this in terms of distance covered, rather than speed:



I’m sorry that the diagram is hard to read, it was a lot harder to fit everything in than I thought it was going to be.

Two hours rowing and 1 of rest is clearly the most efficient unless you have a second crew to take over the rowing while the first one rests.

But, if 3 hrs rowing will carry you to a destination, it’s worth keeping on, even though the crew will need additional rest at the end of it.

Two hours rowing, 1 of rest, and another hour of rowing get you 12x in distance (where x is 1/4 of your best speed). So there are only two circumstances where you might contemplate a fourth straight hour of rowing – where you are attempting to outrun some threat (an enemy, a hurricane, whatever), or where the additional total distance (13x compared to 12x) was enough to get to a destination.

Only the first of those scenarios justifies a fifth hour of rowing – and even then, the distance covered by a 2 row, 1 rest, 2 row pattern is actually greater. It’s that hour of rest that is the critical deciding factor – if the menace is so imminent that you don’t think you can afford that delay, then pushing on beyond the point of exhaustion if necessary, is the only option.

4.6.2 The basics of vector sums

There are three factors that control the movement of vessels: currents, rowing, and wind.

If you have no sails, wind is 1/4 effect. If you have no rowers, but rely on sails for motive power, wind has 4x effect.

To chart the actual motion of a vessel, you need to convert these into the same units and then perform a vector sum operation.

A vector is “speed in a specific direction”. To perform a vector sum, you simply mark out a straight line in the indicated direction that is of a length that corresponds to the speed on whatever scale you’re using. And that makes it sound much more complicated than it really is.

But we complicate matters by then remembering that most of the time, we want to proceed in a specific direction, not simply track what direction we are actually traveling.

To make life simpler, I recommend using “X” as the units – which is a distance per hour equal to 1/4 of your best speed. So if your best speed is 4 mph, you would use mph as your unit scale; if your best speed was 6 mph, you would use units of 1.5 mph.

4.6.2.1 An example

Currents in this part of the world flows 30 degrees to the east of due north at a speed of 6 knots. Winds are currently averaging 14 knots from 20 degrees south of east. Your vessel’s best speed is 4.6 mph.

For a first take, let’s assume we head due west at full speed for an hour.

     1. 6 knots = 6.90467 mph.
     2. 14 knots = 16.1109 mph.
     3. Units = 1/4 of 4.6 = 1.15 mph.
     4. Current = 6.90467 / 1.15 = 6.004 units.
     5. Wind (no sails) = 16.1109 / 4 / 1.15 = 3.502 units.
     6. Hourly vector sum:
     6.1 Currents, 6 units 30°E of N
     6.2 Winds, 3.5 units 20°N of W
     Net effect: almost exactly Due North
     6.3 Rowing: 4 units due West
     6.4 Vector Sum: 33.7°W of North at 7.6 units

6.1 – 6.4 are illustrated below. Each step starts where the last one ends.



4.6.2.2 A better example

The above is all well and good if you actually wanted to travel roughly 35 degrees West of North.

If, as seems more likely, you actually wanted to head due west, the conclusion from the first example is that it isn’t possible – rowing due south would result in a measurable drift north and very little westerly progress.

So, a second example: Same currents, but winds are now 22 knots 20°South of West, and instead of calculating where we would end up by rowing due west, let’s actually try and head due west.

     1. 6 knots = 6.90467 mph.
     2. 22 knots = 25.3171 mph.
     3. Units = 1/4 of 4.6 = 1.15 mph.
     4. Current = 6.90467 / 1.15 = 6.004 units.
     5. Wind (no sails) = 25.3171 / 4 / 1.15 = 4.22 units.
     6. Hourly vector sum:
     6.1 Currents, 6 units 30°E of N
     6.2 Winds, 3.5 units 20°S of W
     Net effect: Drift Movement is mostly North with a slight Westerly element.



From this point, the two examples differ in procedure as well as details.

6.3 From the endpoint of 6.2, drop a southerly line. Since our initial travel is 4 units an hour, draw a circle 4 units in radius. Anywhere on (or in) that circle is reachable with 4 units of rowing. Note that the circle must cut the original line to the west for “Due West” to be a valid outcome. In this example, that is true, but by so little that it’s easy to see why a slight shift in the wind vector was enough to prevent it.
This redefines the objective – we want the vector that cancels out the Northern tendency as efficiently as possible (so that unused movement can be added to the resulting westward drift). That’s what the circle defines for us – at the point where it crosses the east-west line.

6.4 Draw a line from the endpoint of 6.2 through the point where the circle crosses the East-West line. That is the vector direction (we already know the length, 4 units, by definition). I measure that as 27.5° degrees West of South.

The net effect is that the combination of currents and winds move us 1 unit west, and the rowers – after overcoming the tendency to drift north – add another 2 units of motion in that direction. So this particular arrangement is a net 75% efficient.

4.6.2.3 With Maths

It’s possible to use trigonometry to take each of these vectors apart into a North-South component and an East-West component. We know the length of the hypotenuse of the triangle each makes with its starting point and either the angle or 90° minus the angle. Naturally, this is a lot more precise, and if people want or need to go to that much trouble to be precise, more power to them.

4.6.2.4 Simplified Vector Sums

Except in extraordinary circumstances, though, that’s wasted effort chasing unnecessary precision. Heck, even the examples I’ve given above are overkill, only relevant for explaining the technique to someone who has never seen it before.

Do you really think that despite the craft being in motion, with a component of that motion not coming from the elements, that the current it experiences won’t change in the course of an hour? That the winds won’t change direction, or intensity, or – more likely – both? That the wave-tossed craft permits a precise course to be set?

Every value used is an estimated average over the course of the hour. And the ‘estimated’ part restricts the level of precision. In real life, then, this is closer to what I would do:



Vector Directions are about right, and so are quantities. That gets me to the endpoint of 6.2 in 2 calculations and 2 strokes of the pencil – usually with a ruler, but sometimes I won’t even bother with that.

I don’t need the whole circle, either – just the arc, which I can get using the ruler – set the 0 measurement on the 6.2 endpoint and rotate it until the 4 crosses the east-west line. Mark that point and estimate the angle – using the ruler as a temporary north-south line or east-west line. By eye, even without that, I can say that the line is something close to 30 degrees west of south – and the 2.5° difference to the real error is small enough to be swallowed by the other sources of error.

4.6.2.5 Multi-hour Vector Sums

That simplicity is needed because most of the time, one hour won’t be enough to get you where you want to go, as noted earlier. Below are four diagrams, each covering 5 hours of time in different ways, and comparing the net results of each.

The first is obviously the most effective – Five hours continuous rowing, spread amongst two crews (so that each has time to rest while the other rows).

Hour 1: as per Example 2 above. Rowers make some gains to the west but spend most of their efforts combating drift.

Hour 2: Current slightly more northerly and noticeably weaker. Winds weaker and more westerly. Rowers gain even more to the west, but still spend most of their efforts opposing the drift.

Hour 3: Current slightly stronger and more northerly. Winds due West. Rowers spend the entirety of their efforts opposing the current’s northward push, with less than complete success. The only westward movement is from the wind.

Hour 4 Current weaker but more westerly; winds much weaker, but more Northerly. Rowing is the same as Hour 3, and is almost enough to maintain an overall westerly heading.

Hour 5: Current weaker and more westerly, Winds much stronger and more Northerly. Rowers efforts now have to oppose both wind and current, and don’t even come close to complete success.

The chart below the vector sums is what you get when you plot each hour’s end-point. In total, the 5 hours of continuous rowing carried the craft 14.25 units westward (desirable) and 2 units north (undesired). Still, being within only 3 miles (2 units) of the desired destination isn’t bad – wind changes and weaker currents near the coast should permit that to be overcome.



The second figure adjusts the first insofar as it shows the effects of a single crew doing all that rowing, until – at the end of the five hours – they have reached the point of total exhaustion.



Hours 1 and 2 are unchanged.

Hour 3, the rowers only manage three units of movement, and finish considerably more North of the comparative position.

Hour 4 only amplifies the drift to the north,, but they do manage some progress.

Hour 5, and they are really helpless to battle the conditions. In fact they make so little headway that they might have been better off using that hour to rest – it would not have been enough to restore them to full effectiveness, but it would have reduced the need by an hour,.

But, when you measure it out, the crew manage the exact same 14.25 units west – at the price of being pushed 8.5 units north of due west. As usual, if that’s where they really wanted to go, the Navigator is a genius – and if not, he’s close to worthless, or so it might seem to the unhappy crew.

Which brings me to the third figure, below. Instead of forcing the crew to keep rowing, this lets the craft drift while they rest in Hour 3. In Hour 4, they just about master the conditions, halting the northward drift, but in Hour 5 the combination gangs up on them. If, In hour 6, the currents shift to due west or close to it – a bigger shift than has been seen so far – or simply weaken to the point of near insignificance (more likely), the crew would probably be able to hold their losses in a third continuous hour of rowing; they wouldn’t get much further to the west, but they would get maybe a unit more, while not losing anything more to the north.



Again, when you measure it out, you end up with a total westward movement of 14.25 units – something that I doubt people would believe if the diagrams weren’t right there in front of them.

The total northward drift is only 5.6 units – if a unit is 1.5 miles, that’s about 8 1/2 miles in total. I’ve left the “8.5 unit” mark from the previous example to give visual reference for the gains – about 1/3 of the losses are wiped out, and the crew may be tired but they are nowhere near exhausted. Should conditions then change into something more favorable, they could easily regain those 5.6 units in an hour or two.



To round out this section, there is one more scenario worth considering – the one where whoever’s doing the navigating is too clever by half and decides that if a slight drift north is inevitable, they should aim to push south of their destination while they are able.

The figure above shows the results. In total, the crew manage to move about 0.6 units south – but that’s still enough to wipe out twice that much in northward drift. The craft will end the 5 hours about 1.25 miles north of their intended destination.

But what this really illustrates is how you don’t need a lot of precision in your vector sums. Note that this would have negligible impact under either of the other scenarios – resting or one crew working to exhaustion – and that it sacrifices quite a lot of Westerly movement in the process. If the craft was 14.25 units east of port, they will still be 3.35 units out to sea at the end of the five hours. With the first crew only half-way through their second stint at the oars, if conditions are favorable, they might get there in another hour – but if they aren’t much different, the change in final-hour movement will be negligible; they will end up in something close to the same position as the basic two-crew 5-hour continuous rowing result, they’ll just have sweated through an extra hour of hard work for no good reason.

4.6.3 Raft Design & Operation

Rafts are either square or (effectively) rectangular (outriggers don’t count). They have a maximum length to width of 8:5 and a minimum width of 1 foot. If they fall outside those dimensions, they have to be considered a canoe-type vessel.



Generally, the squarer they are, the more stable, and the greater the surface area relative to the length of the sides. However, even square rafts are unstable if too small.

Adding length makes the craft stable front-to-back at some speed – the longer the craft, the lower this speed tends to be. However, if they are too narrow, they remain prone to roll fro one side to the other, sometimes at the slightest provocation. Some sports take advantage of this fact to create single-person craft that are more maneuverable. At that stable speed, even the sideways roll tends to be reduced, so they are only ‘somewhat unstable’ or ‘slightly unstable’.

Increase the size of a square design sufficiently, and it becomes stable in both directions once again. There comes a point at which a new factor becomes increasingly important – the interval between wave crests and troughs. These create, corner to corner or front to back or side-to-side stress that tries to tear the raft apart – which one depends on the angle of motion relative to the direction of the waves, and the line of stress will be at right angles to the direction of the waves relative to the raft.

There are construction techniques that increase the strength of rafts, such as using whole logs for the entire length of the raft. The downside is that as these gain resilience, they also gain weight, and the latter faster than the former (because weight is based n volume and the structural resilience on the cross-sectional area). The rules below will assume that a raft has always been designed in the optimum manner.

Crew that aren’t rowing, provisions, tools, and salvaged cargo occupy the central space. Cargo etc is handled by weight, with the average crewman assigned a nominal weight of 200 lb – so 1 ton of ‘extras’ reduces a raft’s capacity by (1 short ton / 200 lb) crew carried.

It may be possible to rig a small sail on a raft, handling this is left to the GM to improv. No raft will ever be faster than Incredibly Slow.

Above the largest size indicated, the weight of load required to hold a raft together is enough to overcome its buoyancy and it will sink, unless magic is somehow used to prevent this – I leave such variations in the capable hands of the individual GM and their creativity.

4.6.3.1 Buoyancy

Which means that I had better explain buoyancy before I go much further.

Buoyancy is not quite as simple a subject as people think. To explain it more fully, especially with reference to the different configurations of raft permitted under the rules above, I’ve out together the diagram below (I didn’t really want to, but judged it to be necessary).



Water and sky derive from Message In A Bottle from Pixabay.

In the diagram above, we first have a raft consisting of a single row of logs – this is the basic design that most people will immediately think of when hearing the term “raft”. The critical design factor is always the strength with which those logs are held in line – try picking up a number of pencils at the same time, and they will naturally bunch up; viewed end-on, the natural shape is round. That’s what the logs in a raft try to do, too; so they tend to be weaker side-to-side than front-to-back IF single logs / beams run the entire length of the raft.

Typically the buoyancy of wood is only a little more than the force of gravity trying to pull them down. But there is a second buoyancy factor – the resistance to being submerged. This is (essentially) additional buoyancy that only comes into effect when a log is actually submerged. So the raft rides the waves with the upper surface not far above the waterline – and waves will regularly break over that waterline, and the sides of a raft, especially at sea.

Adding a second row of logs doesn’t increase the native buoyancy by much because it also increases the weight. But it does reinforce the strength, and it does increase the secondary buoyancy because the weight forces the bottom row of logs under the surface. As a result, the raft rides a little higher, and is a lot stronger.

The buoyancy can be further increased by hollowing out some or all of the logs, even though this compromises their strength somewhat. This not only reduces the weight but increases the buoyancy and resistance, to the point where the upper row of logs may be completely above the waterline.

Adding a third row increases the weight again, but also increases buoyancy, resistance, and strength. As a result, far greater loads can be supported.

One might think that adding a fourth row would also bring about an improvement, but there are a number of complications – not least of which is that you will now have up-down stresses also trying to tear the raft apart, and reinforcement to prevent this essentially takes you back to the two-log situation, even if the logs are hollowed, or worse. There’s a limit to how far you can go.

Overcoming that limit involves using beams and caulking to seal gaps and removing the logs from the center of the raft – at which point it ceases to be a raft and becomes a ship.

4.6.3.2 Raft Calculation Process

In the course of developing the tables given below, a structured process of raft specification emerged. I wasn’t going to bother sharing this, just the results, but then realized that GMs would need to understand the basis for the different restrictions and limitations placed on rafts.

1. Area in sq feet

This is the key characteristic specified by the person creating the raft.

2. Area in sq meters.

Divide by 10.764 to get area in square meters.

3. (area sq m) ^ 0.5 = minimum rowers per side to achieve full speed.

4. (area sq ft) ^ 0.5 / 3 = minimum width (‘).

5. Creator specifies actual width of this raft.

6. (area sq ft) / min width = length (‘)

7. length / 2 and round down = maximum rowers on each side.

It’s possible for this to be higher than the maximum possible number of people on board (= area /2, see [18] below). This indicates insufficient buoyancy to carry the indicated number of rowers.

This requires a design adjustment – either increasing the buoyancy through [8] below, or reducing the number of pairs of rowers, or both.

8. 5.5 m^2 – 8 m^2 – double row of logs needed. 8.1- 16 m^2 – triple row needed. Above 4 m^2, these are usually hollowed out and the ends sealed to create a buoyancy chamber. Multiply the indicated # of rows by 0.75 if logs are hollowed to get a timber multiplier (value of 1 if not specified).

Hollow Logs reduce the weight of the craft. Additional Rows of logs effectively reduce the effective weight for the purposes of [17] as well.

9. If you have the less than the minimum # of rowers, base speed is 0 and you are at the mercy of the currents. If you have the exact minimum #, actual speed is 10% base speed. If you have the maximum # of rowers indicated then you achieve 100% of base speed. If you have something in between, use

     100 x (rowers – min) / (max – min)

to get the % of base speed this particular raft is capable of. Don’t worry about being too precise, there are too many fudge factors under GM control for this to be anything more than a guideline.

10. ( [7]-[3] ) x 5 = extra base speed from additional rowers (%).

11. width (‘) x 2 + 0.1 and round up = minimum number of logs in a row.

It’s usually more convenient & realistic to round up to the next even number, but sometimes I’ll increase the # of logs to a multiple of 3 (for 3′, 6′, 9′, and 12′ widths). The higher this number, the smaller the diameter of the trees used. This sets the maximum diameter of those trees to 0.5 m (1’ 7.7″) which is quite a big tree.

12. [5] x 5 = base speed lost to water resistance (-%). x0.87 if logs are hollowed, x 1.414 for two rows of logs, x 1.732 for three rows of logs

13. width (‘) / number of logs in a row = average diameter of logs used (‘)

Big trees are heavier than smaller ones but have more buoyancy. If you want that level of realism, you can decide the actual average diameter of the trees used and multiply both weight and capacity by the ratio of (actual / calculated); I’ve simply used the calculated value 99% of the time.

14. Area (sq ft) x log width x [8] = volume of wood in cubic feet.

14a. / 31.315 = volume of wood in cubic meters.

Area is the net of two axes of the theoretical wooden ‘cube’. Log Width x [8] gives the third axis, depth, so this is as simple as this calculation can be made.

15. Multiply [14a] x 550 = Wt (kg).

Raft weights are calculated using estimated volumes and an assumed density of 550kg/m^3, which is the generally accepted value when it comes to the flotation of raw wood. It is assumed that whole logs were used in the construction. Larger rafts (classes 5 & 6) are assumed to have hollowed cores, reducing the weight 25%. Rafts in classes 4 & 5 assume a double row of tree trunks, class 6, a triple row.

Technically, in multi-row designs, the top row is not hollowed so that it can provide greater support and structural integrity, but I have decided that accuracy in this respect is more trouble than it’s worth. I mention it so that you can adjust the results if you disagree.

16. Although it isn’t actually used in the raft system, comparison to sea vessels needs this weight in long tons. So / 1016 to get this if you need it.

17. Solid Logs: (log [Wt (kg)] / 0.30103 [ / (Rows of Logs) ^ 0.5] x 5 = base speed loss to weight (-%)

17a. Hollow Logs: 0.7071 x Solid Log Value (-%)

All sorts of factors cancel out in this calculation or it would be a lot more complicated.

It’s normal to calculate this two ways – the craft with nothing but rowers (maximum possible speed, shown above) and the value with full weight of passengers / cargo included. The latter is the loss at maximum safe load; when an actual load is determined, it will almost always be something either higher or lower. But this gives a useful guideline.

Steps 18-20 determine the absolute maximum number of people that can be safely aboard the craft and converts that into a maximum safe cargo weight (assuming no passengers).

18. Area (sq ft) * (rows of logs^0.5) / 2 (/ 0.75 if hollow logs) = people aboard (safe limit).

People lying down require about 6 sqr ft of area. People sitting up, knees drawn up a little, need 2 sqr ft. People huddled together need 1 sqr ft each. People standing up and squashed together as closely as possible need 0.75 sq ft each. The system uses 2 sqr ft / person to calculate loads because most people are sitting up when they row, but you can squeeze more onto a raft, overloading it.

19. [18] – (2 x [7]) = passenger space.

20. 200 x [19] = cargo space (kg).

The system uses an average weight of 200 kg per person, representing both the individual, the additional weight of water in wet clothing, arms, equipment, etc. I thought about using a smaller value but found that the system works better when using something close to a ‘worst case’ value.

Note that passengers occupy, and count as, cargo space. [19] is not ‘in addition to’ them, it includes them.

You can squeeze extra people on board a raft in complete safety – if everybody sheds enough weight. It might mean that there isn’t enough room for everyone to sit down at once.

21. [19] / 907.2 to get cargo space in short tons, if needed, or / 1000 to get it in tonnes – whatever makes conversion to trade units most convenient.

22. Raft base speed is based on 3 mph* = 4.828 km/h* = 264 ft/min* = 4.4 ft/sec = 80.47* m/m = 1.34 m/sec. The values marked with an asterisk are the ones most commonly used for practical purposes.

4.6.3.3 Why all this matters:

Nonhumans. Halflings, Ogres, Dwarves, Elves, you name it. Anything that doesn’t fit standard human silhouettes, size, weights, etc

For actual ships, I’ve got a relatively simple solution, it can even cater for mixed-race crews. But for some reason, it just doesn’t work properly for rafts.

That means that GMs are going to have to fudge the adjustments that are necessary for themselves. Earlier chapters have given you all the specifications about the races that you need, and enabled you to customize them to your world. Now you get to put that work to good use.

4.6.3.4 Category 1 Raft Table

Category #		1
Name		Raft / Canoe 1
Area m^2		0.5017	0.65		0.65		0.65	0.799
Area sq ft		5.4	7		7		7	8.6
Width ft		2‘	1‘		1.75‘		2.64’	4‘
Length ft		2.7‘	7‘		4‘		2.65’	4.3‘
Min Rowers		0.22	0.806		0.806		0.806	0.894
Max Rowers		1	1 †	2	1 †	2	1	2
Logs / Row		5	4	4	5	5	6	8
Factor		1	1	0.75	1	0.75	1	1
Row Depth ft		0.4‘	1 / 4‘	1 / 4‘	0.35‘	0.35’	0.4417‘	0.25‘
Volume cu ft		2.16 cu ft	1.75 cu ft	1.31 cu ft	2.45 cu ft	1.84 cu ft	3.092 cu ft	4.3 cu ft
Volume m^3 (/31.315)		0.069 m^3	0.05 m^3	0.0375 m^3	0.07 m^3	0.06 m^3	0.08756 m^3	0.122 m^3
Wt kg		37.95 kg	27.5 kg	20.625 kg	38.5 kg	33 kg	48.16 kg	67.1 kg
Wt lt (/1016)		0.0375 lt	0.027 lt	0.02 lt	0.038 lt	0.0325 lt	0.0474 lt	0.066 lt
Max Pass		0.7	1.5	0.67	1.5	0.67	1.5	0.3
Max Cargo kg		140 kg	300 kg	134 kg	300 kg	134 kg	300 kg	60 kg
Max Cargo t (/907.2)		0.15 tons	0.33 tons	0.15 tons	0.33 tons	0.15 tons	0.33 tons	0.07 tons
Max Cargo T		0.14 Tonnes	0.3 Tonnes	0.134 Tonnes	0.3 Tonnes	0.134 Tonnes	0.3 Tonnes	0.06 Tonnes
Spd Rowers		+7.8%	+1.94%	+11.94%	+1.94%	+11.94%	+1.94%	+11.06%
Spd Width		-10%	-5%	-4.35%	-8.75%	-7.61%	-13.2%	-20%
Spd Weight		-26.2% – -37.4%	-23.9% – -41.8%	-15.4% – -25.7%	-26.3% – -42%	-17.8% – -26.1%	-27.9% – -42.2%	-30.3% – -34.9%
100+Tot Mod		71.6% – 60.4%	73.04% – 55.14%	92.18% – 81.89%	66.89% – 51.18%	86.53% – 76.23%	60.84% – 46.54%	60.76% – 56.16%
Max Spd	x264	189 ft/min	192.8 ft/min	234.4 ft/min	176.6 ft/min	228.4 ft/min	160.6 ft/min	160.4 ft/min
	/ 3.281	57.62 m/min	58.78 m/min	74.19 m/min	53.83 m/min	69.63 m/min	48.96 m/min	48.89 m/min
	/ 26.82	2.148 mph	2.191 mph	2.766 mph	2.007 mph	2.596 mph	1.825 mph	1.823 mph
	x1.609	3.457 km/h	3.526 km/h	4.451 km/h	3.229 km/h	4.178 km/h	2.937 km/h	2.933 km/h
Fully Loaded Spd	x264	159.5 ft/min	145.6 ft/min	216.2 ft/min	135.1 ft/min	206.5 ft/min	122.9 ft/min	148.3 ft/min
	/ 3.281	48.6 m/min	44.37 m/min	65.9 m/min	41.19 m/min	62.95 m/min	37.45 m/min	45.19 m/min
	/ 26.82	1.812 mph	1.654 mph	2.457 mph	1.536 mph	2.347 mph	1.396 mph	1.685 mph
	x1.609	2.916 km/h	2.662 km/h	3.954 km/h	2.471 km/h	3.777 km/h	2.247 km/h	2.711 km/h

† Craft could have more rowers by length but does not have sufficient buoyancy to hold them.
 

4.6.3.5 Category 2 Raft Table



Image by Gordon Johnson from Pixabay

Category #		2
Name		Raft / Canoe 2
Area m^2		0.8	1.115	1.115	1.115	1.115	1.5	1.5
Area sq ft		8.6	12	12	12	12	16.15	16.15
Width ft		2′	2′	2.5′	3′	3.46′	2.5’	3′
Length ft		4.3′	6′	4.8′	4′	3.47′	6.46 ’	5.38’
Min Rowers		0.894	1.056	1.056	1.056	1.056	1.225	1.225
Max Rowers		2	3	2	2	1	3	2
Logs / Row		6	6	6	6	8	8	8
Factor		1	1	1	1	1	1	1
Row Depth ft		1/3′	1/3′	0.417′	0.5′	0.4325′	5/16′	3/8′
Volume cu ft		2.87 cu ft	4 cu ft	5.004 cu ft	6 cu ft	5.19 cu ft	5.05 cu ft	6.05 cu ft
Volume m^3 (/31.315)		0.08 m^3	0.11327 m^3	0.1417 m^3	0.17 m^3	0.147 m^3	0.143 m^3	0.1713 m^3
Wt kg		44 kg	62.3 kg	77.94 kg	93.5 kg	80.85 kg	78.65 kg	94.2 kg
Wt lt (/1016)		0.043 lt	0.06 lt	0.0767 lt	0.092 lt	0.796 lt	0.0774 lt	0.093 lt
Max Pass		0.3	0	2	2	4	2.08	4.08
Max Cargo kg		60 kg	0	400 kg	400 kg	800 kg	416 kg	816 kg
Max Cargo t (/907.2)		0.07 tons	0	0.44 tons	0.44 tons	0.88 tons	0.46 tons	0.9 tons
Max Cargo T		0.06 Tonnes	0	0.4 Tonnes	0.4 Tonnes	0.8 Tonnes	0.416 Tonnes	0.816 Tonnes
Spd Rowers		+11.06%	+19.44%	+9.44%	+9.44%	-0.57%	+17.75%	+7.75%
Spd Width		-10%	-10%	-12.5%	-15%	-17.3%	-12.5%	-15%
Spd Wt		-10.7% – -30%	-29.8%	-31.4% – -44.5%	-32.7% – -44.7%	-31.7% – -48.9%	-31.5% – -48.9%	-32.8% – -49.2%
100+Tot Mod		90.36% – 71.06%	79.64	65.54% – 52.44%	61.74% – 49.74%	50.43% – 33.23%	73.75% – 60.45%	59.95% – 43.55%
Max Spd	x264	238.6 ft/min	210.2 ft/min	173 ft/min	163 ft/min	133.1 ft/min	194.7 ft/min	158.3 ft/min
	/ 3.281	72.71 m/min	64.09 m/min	52.74 m/min	49.68 m/min	40.58 m/min	59.35 m/min	48.24 m/min
	/ 26.82	2.711 mph	2.389 mph	1.966 mph	1.852 mph	1.513 mph	2.213 mph	1.799 mph
	x1.609	4.363 km/h	3.845 km/h	3.164 km/h	2.981 km/h	2.435 km/h	3.561 km/h	2.894 km/h
Fully Loaded Spd	x264	187.6 ft/min	210.2 ft/min	138.4 ft/min	131.3 ft/min	87.7 ft/min	159.6 ft/min	115 ft/min
	/ 3.281	57.18 m/min	64.09 m/min	42.2 m/min	40.03 m/min	26.74 m/min	48.64 m/min	35.04 m/min
	/ 26.82	2.132 mph	2.389 mph	1.573 mph	1.492 mph	0.997 mph	1.814 mph	1.307 mph
	x1.609	3.431 km/h	3.845 km/h	2.532 km/h	2.401 km/h	1.604 km/h	2.919 km/h	2.103 km/h

4.6.3.6 Category 3 Raft Table



Image by ktuec from Pixabay

Category #		3
Name		Raft / Canoe 3
Area m^2		1.5	2.508	2.508	2.508	2.508	2.508	3.5	3.5
Area sq ft		16.15	27	27	27	27	27	37.7	37.7
Width ft		2 ‘	1.75 ‘	2 ‘	3 ‘	4.5 ‘	5 ‘	4 ’	6.14 ‘
Length ft		8.075 ‘	15.43 ‘	13.5 ‘	9 ‘	6 ‘	5.4 ‘	9.425 ’	6.14 ‘
Min Rowers		1.225	1.584	1.584	1.584	1.584	1.584	1.871	1.871
Max Rowers		4	6 †	6	4	3	2	4	3
Logs / Row		6	4	6	8	10	12	10	15
Factor		1	1	1	1	1	1	0.75	1
Row Depth ft		1/3 ‘	0.4375 ‘	1/3 ‘	0.375 ‘	0.45 ‘	0.417 ‘	0.4 ‘	0.409 ‘
Volume cu ft		5.38 cu ft	11.81 cu ft	9 cu ft	10.125 cu ft	12.15 cu ft	11.3 cu ft	11.08 cu ft	15.42 cu ft
Volume m^3 (/31.315)		0.1523 m^3	0.3345 m^3	0.255 m^3	0.2867 m^3	0.344 m^3	0.32 m^3	0.354 m^3	0.492 m^3
Wt kg		83.77 kg	184 kg	140.25 kg	157.7 kg	189.2 kg	176 kg	194.7 kg	270.8 kg
Wt lt (/1016)		0.082 lt	0.18 lt	0.14 lt	0.155 lt	0.186 lt	0.173 lt	0.192 lt	0.267 lt
Max Pass		0.07	1.5	1.5	5.5	7.5	9.5	17.13	12.85
Max Cargo kg		14 kg	300 kg	300 kg	1100 kg	1500 kg	1900 kg	3426 kg	2570 kg
Max Cargo t (/907.2)		0.02 tons	0.33 tons	0.33 tons	1.21 tons	1.65 tons	2.09 tons	3.78 tons	2.83 tons
Max Cargo T		0.014 Tonnes	0.3 Tonnes	0.3 Tonnes	1.1 Tonnes	1.5 Tonnes	1.9 Tonnes	3.426 Tonnes	2.57 Tonnes
Spd Rowers		+27.75%	+44.16%	+44.16%	+24.16%	+14.16%	+4.16%	+21.29%	+11.29%
Spd Width		-10%	-8.75%	-10%	-15%	-22.5%	-25%	-17.4%	-30.7%
Spd Wt		-31.9% – -33.1%	-37.6% – -44.6%	-35.7% – -43.9%	-36.5% – -51.5%	-37.8% – -53.6%	-37.3% – -55.1%	-26.9% – -41.8%	-40.4% – -57.4%
100+Tot Mod		85.85% – 84.65%	97.81% – 90.81%	98.46% – 90.26%	72.66% – 57.66%	53.86% – 38.06%	41.86% – 24.06%	76.99% – 62.09%	40.18% – 23.18%
Max Spd	x264	226.6 ft/min	258.2 ft/min	259.9 ft/min	191.8 ft/min	142.2 ft/min	110.5 ft/min	203.3 ft/min	106.1 ft/min
	/ 3.281	69.08 m/min	78.71 m/min	79.23 m/min	58.47 m/min	43.34 m/min	33.68 m/min	61.95 m/min	32.34 m/min
	/ 26.82	2.576 mph	2.934 mph	2.954 mph	2.18 mph	1.616 mph	1.256 mph	2.31 mph	1.206 mph
	x1.609	4.145 km/h	4.722 km/h	4.754 km/h	3.508 km/h	2.6 km/h	2.021 km/h	3.717 km/h	1.94 km/h
Fully Loaded Spd	x264	223.5 ft/min	239.7 ft/min	238.3 ft/min	152.2 ft/min	100.5 ft/min	63.5 ft/min	163.9 ft/min	61.2 ft/min
	/ 3.281	68.12 m/min	73.07 m/min	72.63 m/min	46.4 m/min	30.63 m/min	19.36 m/min	49.96 m/min	18.66 m/min
	/ 26.82	2.54 mph	2.724 mph	2.708 mph	1.73 mph	1.142 mph	0.722 mph	1.863 mph	0.696 mph
	x1.609	4.087 km/h	4.384 km/h	4.358 km/h	2.784 km/h	1.838 km/h	1.162 km/h	2.998 km/h	1.12 km/h

† Craft could have more rowers by length but does not have sufficient buoyancy to hold them.

4.6.3.7 Category 4 Raft Tables



Image by Natalia K from Pixabay

Category #		4a
Name		Raft / Canoe 4 table 1
Area m^2		3.5	3.5	3.5	4.645	4.645
Area sq ft		37.7	37.7	37.7	50	50
Width ft		2.05 ‘	3 ‘	4 ‘	2.36 ‘	4 ’
Length ft		18.4 ‘	12.23 ‘	9.425 ‘	21.19 ‘	12.5 ‘
Min Rowers		1.871	1.871	1.871	2.16	2.16
Max Rowers		9	6	4	10	6
Logs / Row		6	8	10	7	10
Factor		1	1	1	1	1
Row Depth ft		0.3417 ‘	0.375 ‘	0.4 ‘	0.337 ‘	0.4 ‘
Volume cu ft		12.882 cu ft	14.138 cu ft	15.08 cu ft	16.85 cu ft	20 cu ft
Volume m^3 (/31.315)		0.411 m^3	0.451 m^3	0.482 m^3	0.538 m^3	0.639 m^3
Wt kg		226.05 kg	248.05 kg	265.1 kg	295.9 kg	351.3 kg
Wt lt (/1016)		0.2225 lt	0.244 lt	0.261 lt	0.29 lt	0.35 lt
Max Pass		7.13	6.85	10.85	5	13
Max Cargo kg		1426 kg	1370 kg	2170 kg	1000 kg	2600 kg
Max Cargo t (/907.2)		1.57 tons	1.51 tons	2.39 tons	1.1 tons	2.87 tons
Max Cargo T		1.426 Tonnes	1.37 Tonnes	2.17 Tonnes	1 Tonne	2.6 Tonnes
Spd Rowers		+71.29%	+41.29%	+21.29%	+78.4%	+38.4%
Spd Width		-8.92%	-15%	-20%	-11.8%	-20%
Spd Wt		-27.7% – -37.8%	-39.8% – -53.3%	-40.3% – -56.2%	-41% – -51.7%	-42.3% – -57.6%
100+Tot Mod		134.67% – 124.57%	86.49% – 72.99%	60.99% – 45.09%	125.6% – 114.9%	76.1% – 114.9%
Max Spd	x264	355.5 ft/min	228.3 ft/min	161 ft/min	331.6 ft/min	200.9 ft/min
	/ 3.281	108.37 m/min	69.6 m/min	49.08 m/min	101.07 m/min	61.24 m/min
	/ 26.82	4.04 mph	2.595 mph	1.83 mph	3.768 mph	2.283 mph
	x1.609	6.502 km/h	4.176 km/h	2.945 km/h	6.064 km/h	3.674 km/h
Fully Loaded Spd	x264	328.9 ft/min	192.7 ft/min	119 ft/min	303.8 ft/min	160.5 ft/min
	/ 3.281	100.24 m/min	58.74 m/min	36.28 m/min	92.46 m/min	48.93 m/min
	/ 26.82	3.737 mph	2.19 mph	1.353 mph	3.447 mph	1.824 mph
	x1.609	6.014 km/h	3.524 km/h	2.177 km/h	5.547 km/h	2.935 km/h

‡ Reducing the number of rowers would slow the craft but add 400kg cargo capacity per pair of rowers eliminated.

Category #		4b
Name		Raft / Canoe 4 table 2
Area m^2		4.645	4.645	5.5	5.5	5.5
Area sq ft		50	50	59.2	59.2	59.2
Width ft		6 ‘	7 ‘	3 ‘	4 ‘	5.92 ‘
Length ft		8.33 ‘	7.143 ‘	19.73 ‘	14.8 ‘	10 ‘
Min Rowers		2.16	2.16	2.345	2.345	2.345
Max Rowers		4	3	9	7	5
Logs / Row		15	16	9	10	12
Factor		1	1	1	1	1
Row Depth ft		0.4 ‘	0.438 ‘	1/3 ‘	0.4 ‘	0.493 ‘
Volume cu ft		20 cu ft	21.9 cu ft	19.73 cu ft	23.68 cu ft	29.12 cu ft
Volume m^3 (/31.315)		0.639 m^3	0.7 m^3	0.63 m^3	0.756 m^3	0.93 m^3
Wt kg		351.3 kg	384.6 kg	346.5 kg	415.8 kg	511.5 kg
Wt lt (/1016)		0.35 lt	0.38 lt	0.341 lt	0.41 lt	0.5 lt
Max Pass		17	19	11.6	15.6	19.6
Max Cargo kg		3400 kg	3800 kg	2320 kg	3120 kg	3920 kg
Max Cargo t (/907.2)		3.75 tons	4.19 tons	2.56 tons	3.44 tons	4.321 tons
Max Cargo T		3.4 Tonnes	3.8 Tonnes	2.32 Tonnes	3.12 Tonnes	3.92 Tonnes
Spd Rowers		+18.4%	+8.4%	+66.55%	+46.55%	+26.55%
Spd Width		-30%	-35%	-15%	-20%	-29.6%
Spd Wt		-42.3% – -59.4%	-42.9% – -60.2%	-42.2% – -56.9%	-43.5% – -58.9%	-45% – -60.6%
100+Tot Mod		46.1% – 29%	30.5% – 13.2%	109.35% – 94.65%	83.05% – 67.65%	51.95% – 36.35%
Max Spd	x264	121.7 ft/min	80.5 ft/min	288.7 ft/min	219.3 ft/min	137.1 ft/min
	/ 3.281	37.1 m/min	24.54 m/min	87.99 m/min	66.83 m/min	41.8 m/min
	/ 26.82	1.8383 mph	0.915 mph	3.281 mph	2.492 mph	1.559 mph
	x1.609	2.226 km/h	1.473 km/h	5.279 km/h	4.01 km/h	2.508 km/h
Fully Loaded Spd	x264	76.6 ft/min	34.8 ft/min	249.9 ft/min	178.6 ft/min	96 ft/min
	/ 3.281	23.34 m/min	10.62 m/min	76.16 m/min	54.44 m/min	29.25 m/min
	/ 26.82	0.87 mph	0.396 mph	2.84 mph	2.03 mph	1.091 mph
	x1.609	1.4 km/h	0.638 km/h	4.57 km/h	3.266 km/h	1.755 km/h

4.6.3.8 Category 5 Raft Tables



Image by Heike Frohnhoff from Pixabay

Category #		5a
Name		Raft / Canoe 5 table 1
Area m^2		5.5 m^2	5.5 m^2	7.43 m^2	7.43 m^2	7.43 m^2
Area sq ft		59.2	59.2	80	80	80
Width ft		2.565 ‘	3.37 ‘	3 ‘	4.5 ‘	6 ‘
Length ft		23.08 ‘	17.57 ‘	26.7 ‘	17.78 ‘	13.33 ‘
Min Rowers		2.345	2.345	2.726	2.726	2.726
Max Rowers		11	8	13	8	6
Logs / Row		8	8	8	10	15
Factor		x1.5	x1.5	x1.5	x1.5	x1.5
Row Depth ft		0.293 ‘	0.421 ‘	0.375 ‘	0.45 ‘	0.4 ‘
Volume cu ft		26.02 cu ft	37.385 cu ft	45 cu ft	54 cu ft	48 cu ft
Volume m^3 (/31.315)		0.8309 m^3	1.194 m^3	1.437 m^3	1.725 m^3	1.533 m^3
Wt kg		457 kg	656.7 kg	790.35 kg	948.75 kg	843 kg
Wt lt (/1016)		0.45 lt	0.646 lt	0.778 lt	0.934 lt	0.83 lt
Max Pass		56.93	62.93	80.67	90.67	94.67
Max Cargo kg		11 386 kg	12 586 kg	16 134 kg	18 134 kg	18 934 kg
Max Cargo t (/907.2)		12.55 tons	13.87 tons	17.78 tons	19.99 tons	20.87 tons
Max Cargo T		11.386 Tonnes	12.586 Tonnes	16.134 Tonnes	18.134 Tonnes	18.934 Tonnes
Spd Rowers		+86.55%	+56.55%	+102.74%	+52.74%	+32.74%
Spd Width		-15.78%	-20.73%	-18.46%	-27.68%	-36.91%
Spd Wt		-22.1% – -33.8%	-23.4% – -34.2%	-24.1% – -35.1%	-24.7% – -35.5%	-24.3% – -35.7%
100+Tot Mod		148.67% – 136.97%	112.42% – 101.62%	160.18% – 149.18%	100.36% – 89.56%	71.53% – 60.13%
Max Spd	x264	392.5 ft/min	296.8 ft/min	422.9 ft/min	265 ft/min	188.8 ft/min
	/ 3.281	119.63 m/min	90.45 m/min	128.9 m/min	80.76 m/min	57.56 m/min
	/ 26.82	4.46 mph	3.373 mph	4.805 mph	3.011 mph	2.146 mph
	x1.609	7.178 km/h	5.428 km/h	7.733 km/h	4.845 km/h	3.453 km/h
Fully Loaded Spd	x264	361.6 ft/min	268.3 ft/min	393.8 ft/min	236.4 ft/min	158.7 ft/min
	/ 3.281	110.22 m/min	81.77 m/min	120.05 m/min	72.07 m/min	48.39 m/min
	/ 26.82	4.109 mph	3.049 mph	4.475 mph	2.687 mph	1.804 mph
	x1.609	6.613 km/h	4.906 km/h	7.702 km/h	4.324 km/h	2.903 km/h

Category #		5b
Name		Raft / Canoe 5 table 2
Area m^2		7.43 m^2	7.43 m^2	7.43 m^2	9.5 m^2	9.5 m^2	9.5 m^2
Area sq ft		80	80	80	102.26	102.26	102.26
Width ft		7.5 ‘	8 ‘	8.9 ‘	3.37 ‘	5.8 ‘	10.11 ’
Length ft		10.67 ‘	10 ‘	8.97 ‘	30.34 ‘	17.63 ‘	10.15 ’
Min Rowers		2.726	2.726	2.726	3.082	3.082	3.082
Max Rowers		5	5	4	15	8	5
Logs / Row		16	18	20	8	12	25
Factor		x1.5	x1.5	x1.5	x1.5	x1.5	x1.5
Row Depth ft		0.469 ‘	0.444 ‘	0.445 ‘	0.421 ‘	0.483 ‘	0.4044 ‘
Volume cu ft		56.28 cu ft	53.28 cu ft	53.4 cu ft	64.575 cu ft	74.085 cu ft	62.03 cu ft
Volume m^3 (/31.315)		1.797 m^3	1.7 m^3	1.705 m^3	2.062 m^3	2.366 m^3	1.981 m^3
Wt kg		988.5 kg	935 kg	937.75 kg	1134 kg	1301.3 kg	1089.55 kg
Wt lt (/1016)		0.973 lt	0.92 lt	0.923 lt	1.116 lt	1.281 lt	1.0724 lt
Max Pass		96.67	96.67	98.67	100.35	120.35	126.35
Max Cargo kg		19 334 kg	19 334 kg	19 734 kg	20 070 kg	24 070 kg	25 270 kg
Max Cargo t (/907.2)		21.31 tons	21.31 tons	21.75 tons	22.12 tons	26.53 tons	27.85 tons
Max Cargo T		19.334 Tonnes	19.334 Tonnes	19.734 Tonnes	20.07 Tonnes	24.07 Tonnes	25.27 Tonnes
Spd Rowers		+22.74%	+22.72%	+12.74%	+149.18%	+49.18%	+19.18%
Spd Width		-46.14%	-49.21%	-54.75%	-20.73%	-35.68%	-62.18%
Spd Wt		-24.9% – -35.8%	-24.7% – -35.8%	-24.7% – -35.8%	-25.4% – -35.9%	-259.9% – -36.6%	-25.2% – -26.7%
100+Tot Mod		51.7% – 40.8%	48.81% – 37.71%	33.29% – 22.18%	203.05% – 192.5%	87.6% – 76.9%	31.79% – 20.29%
Max Spd	x264	136.5 ft/min	128.9 ft/min	87.9 ft/min	536.1 ft/min	231.3 ft/min	83.9 ft/min
	/ 3.281	41.6 m/min	39.28 m/min	26.79 m/min	163.39 m/min	70.49 m/min	25.58 m/min
	/ 26.82	1.551 mph	1.464 mph	0.999 mph	6.092 mph	2.628 mph	0.954 mph
	x1.609	2.496 km/h	2.357 km/h	1.607 km/h	9.803 km/h	4.229 km/h	1.535 km/h
Fully Loaded Spd	x264	107.7 ft/min	99.6 ft/min	58.6 ft/min	508.3 ft/min	203 ft/min	53.6 ft/min
	/ 3.281	32.83 m/min	30.35 m/min	17.86 m/min	154.94 m/min	61.88 m/min	16.33 m/min
	/ 26.82	1.224 mph	1.131 mph	0.666 mph	5.777 mph	2.307 mph	0.609 mph
	x1.609	1.97 km/h	1.821 km/h	1.071 km/h	9.296 km/h	3.713 km/h	0.98 km/h

4.6.3.9 Category 6 Raft Tables



Image by Mike Goad from Pixabay

Category #		6a
Name		Raft / Canoe 6 table 1
Area m^2		9.5 m^2	9.5 m^2	11.15 m^2	11.15 m^2	11.15 m^2	11.15 m^2
Area sq ft		102.26	102.26	120	120	120	120
Width ft		3.37 ‘	4.4 ‘	3.65 ‘	5 ‘	6 ‘	8 ‘
Length ft		30.34 ‘	23.24 ‘	32.876 ‘	24 ‘	20 ‘	15 ‘
Min Rowers		3.082	3.082	3.34	3.34	3.34	3.34
Max Rowers		15	11	4	15	8	7
Logs / Row		8	10	10	12	15	20
Factor		x1.5	x1.5	x2.25	x2.25	x2.25	x2.25
Row Depth ft		0.42125	0.44	0.365	0.417	0.4	0.4
Volume cu ft		64.616 cu ft	67.49 cu ft	98.55 cu ft	112.59 cu ft	108 cu ft	108 cu ft
Volume m^3 (/31.315)		2.063 m^3	2.06 m^3	3.147 m^3	3.6 m^3	3.45 m^3	3.45 m^3
Wt kg		1134.9 kg	1132.67 kg	1730.88 kg	1977.5 kg	1896.85 kg	1896.85 kg
Wt lt (/1016)		1.117 lt	1.148 lt	1.704 lt	1.946 lt	1.867 lt	1.867 lt
Max Pass		106.35	114.35	232	210	224	226
Max Cargo kg		21 270 kg	22 870 kg	46 400 kg	42 000 kg	44 800 kg	45 200 kg
Max Cargo t (/907.2)		23.45 tons	25.21 tons	51.15 tons	46.3 tons	49.38 tons	49.82 tons
Max Cargo T		21.27 Tonnes	22.87 Tonnes	46.4 Tonnes	42 Tonnes	44.8 Tonnes	45.2 Tonnes
Spd Rowers		+119.18%	+79.18%	+6.6%	+116.6%	+46.6%	+36.6%
Spd Width		-51.92%	-44.46%	-29.06%	-56.27%	-41.09%	-38.44%
Spd Wt		-14.8% – -54.5%	-13.1% – -54.9%	-7.6% – -58.8%	-14.8% – -58.2%	-11.4% – -58.6%	-10.6% – -58.6%
100+Tot Mod		152.46% – 112.76%	121.62% – 79.82%	69.94% – 18.74%	145.53% – 102.13%	94.11% – 46.91%	87.56% – 39.56%
Max Spd	x264	402.5 ft/min	321.1 ft/min	184.6 ft/min	384.2 ft/min	248.5 ft/min	231.2 ft/min
	/ 3.281	122.68 m/min	97.87 m/min	56.28 m/min	117.11 m/min	75.73 m/min	70.46 m/min
	/ 26.82	4.574 mph	3.649 mph	2.098 mph	4.366 mph	2.823 mph	2.627 mph
	x1.609	7.361 km/h	5.872 km/h	3.377 km/h	7.026 km/h	4.544 km/h	4.227 km/h
Fully Loaded Spd	x264	297.7 ft/min	210.7 ft/min	49.5 ft/min	269.6 ft/min	123.8 ft/min	104.4 ft/min
	/ 3.281	90.74 m/min	64.23 m/min	15.08 m/min	82.18 m/min	37.75 m/min	31.83 m/min
	/ 26.82	3.383 mph	2.395 mph	0.562 mph	3.064 mph	1.407 mph	1.187 mph
	x1.609	5.444 km/h	3.854 km/h	0.905 km/h	4.931 km/h	2.265 km/h	1.91 km/h



Image by Juliano from Pixabay

Category #		6b
Name		Raft / Canoe 6 table 2
Area m^2		11.15 m^2	12.08 m^2	12.08 m^2	13.47 m^2	13.47 m^2	13.47 m^2
Area sq ft		120	130	130	145	145	145
Width ft		10 ‘	6.5 ‘	10 ‘	4.02 ‘	5 ‘	8 ‘
Length ft		12 ‘	20 ‘	13 ‘	36.07 ‘	29 ‘	18.125 ‘
Min Rowers		3.34	3.476	3.476	3.67	3.67	3.67
Max Rowers		6	10	6	18	14	9
Logs / Row		24	15	25	10	15	20
Factor		x2.25	x2.25	x2.25	x2.25	x2.25	x2.25
Row Depth		0.417	0.433	0.4	0.402	1/3	0.4
Volume cu ft		112.59 cu ft	126.65 cu ft	117 cu ft	131.2 cu ft	108.75 cu ft	130.5 cu ft
Volume m^3 (/31.315)		3.595 m^3	4.045 m^3	3.736 m^3	4.188 m^3	3.473 m^3	4.167 m^3
Wt kg		1977.5 kg	2224.5 kg	2054.9 kg	2203.5 kg	1910 kg	2292 kg
Wt lt (/1016)		1.95 lt	2.19 lt	2.023 lt	2.267 lt	1.88 lt	2.256 lt
Max Pass		228	240	248	254	262	272
Max Cargo kg		45 600 kg	48 000 kg	49 600 kg	50 800 kg	52 400 kg	54 400 kg
Max Cargo t (/907.2)		50.26 tons	52.91 tons	54.67 tons	56 tons	57.76 tons	59.96 tons
Max Cargo T		45.6 Tonnes	48 Tonnes	49.6 Tonnes	50.8 Tonnes	52.4 Tonnes	54.4 Tonnes
Spd Rowers		+26.6%	+65.24%	+25.24%	+143.3%	+103.3%	+53.3%
Spd Width		-35.59%	-47.82%	-37.04%	-67.73%	-59.73%	-47.89%
Spd Wt		-9.8% – -58.7%	-12.6% – -58.9%	-9.8% – -59.1%	-15.8% – -59.3%	-14.4% – -59.4%	-12% – -59.6%
100+Tot Mod		81.21% – 32.31%	104.82% – 58.52%	78.4% – 29.1%	159.77% – 116.27%	129.17% – 84.17%	93.41% – 45.81%
Max Spd	x264	214.4 ft/min	276.7 ft/min	207 ft/min	421.8 ft/min	341 ft/min	246.6 ft/min
	/ 3.281	65.35 m/min	84.35 m/min	63.09 m/min	128.57 m/min	103.94 m/min	75.17 m/min
	/ 26.82	2.436 mph	3.145 mph	2.352 mph	4.7963 mph	3.875 mph	2.802 mph
	x1.609	3.921 km/h	5.061 km/h	3.785 km/h	7.714 km/h	6.236 km/h	4.51 km/h
Fully Loaded Spd	x264	85.3 ft/min	154.5 ft/min	76.8 ft/min	307 ft/min	222.2 ft/min	120.9 ft/min
	/ 3.281	26 m/min	47.09 m/min	23.42 m/min	93.56 m/min	67.73 m/min	36.86 m/min
	/ 26.82	0.969 mph	1.756 mph	0.873 mph	3.488 mph	2.525 mph	1.374 mph
	x1.609	1.56 km/h	2.825 km/h	1.405 km/h	5.614 km/h	4.064 km/h	2.212 km/h

Category #		6c
Name		Raft / Canoe 6 table 3
Area m^2		13.47 m^2	13.47 m^2	14.86 m^2	14.86 m^2	14.86 m^2	14.86 m^2
Area sq ft		145	145	160	160	160	160
Width ft		10 ‘	12 ‘	4.3 ‘	5 ‘	8 ‘	10 ‘
L ft		14.5 ‘	12.083 ‘	37.21 ‘	32 ‘	20 ‘	16 ‘
Min Rowers		3.67	3.67	3.855	3.855	3.855	3.855
Max Rowers		7	6	18	16	10	8
Logs / Row		24	25	12	12	20	25
Factor		x2.25	x2.25	x2.25	x2.25	x2.25	x2.25
Row Depth		0.417	0.48	0.358	0.417	0.4	0.4
Volume cu ft		136.05 cu ft	156.6 cu ft	128.88 cu ft	150.12 cu ft	144 cu ft	144 cu ft
Volume m^3 (/31.315)		4.344 m^3	5.001 m^3	4.116 m^3	4.794 m^3	4.6 m^3	4.6 m^3
Wt kg		2389 kg	2750.44 kg	2263.68 kg	2636.6 kg	2529.1 kg	2529.1 kg
Wt lt (/1016)		2.352 lt	2.707 lt	2.228 lt	2.6 lt	2.489 lt	2.489 lt
Max Pass		276	278	284	288	300	304
Max Cargo kg		55 200 kg	55 600 kg	56 800 kg	57 600 kg	60 000 kg	60 800 kg
Max Cargo t (/907.2)		60.85 tons	61.29 tons	62.61 tons	63.49 tons	66.14 tons	67.02 tons
Max Cargo T		55.2 Tonnes	55.6 Tonnes	56.8 Tonnes	57.6 Tonnes	60 Tonnes	60.8 Tonnes
Spd Rowers		+33.3%	+23.3%	+141.45%	+121.45%	+61.45%	+41.45%
Spd Width		-42.24%	-39.1%	-71.15%	-67.08%	-53.03%	-47.43%
Spd Wt		-10.6% – -59.7%	-9.8% – -59.7%	-15.8% – -59.9%	-15.2% – -59.9%	-12.6% – -60.2%	-11.4% – -60.2%
100+Tot Mod		80.46% – 31.36%	74.4% – 24.5%	154.5% – 110.4%	139.17% – 94.47%	95.82% – 48.22%	82.62% – 33.82%
Max Spd	x264	212.4 ft/min	196.4 ft/min	407.9 ft/min	367.4 ft/min	253 ft/min	218.1 ft/min
	/ 3.281	64.75 m/min	50.87 m/min	124.33 m/min	111.99 m/min	77.11 m/min	66.48 m/min
	/ 26.82	2.414 mph	2.232 mph	4.635 mph	4.175 mph	2.875 mph	2.479 mph
	x1.609	3.885 km/h	3.592 km/h	7.459 km/h	6.719 km/h	4.626 km/h	3.989 km/h
Fully Loaded Spd	x264	82.8 ft/min	64.7 ft/min	291.5 ft/min	249.4 ft/min	127.3 ft/min	80.3 ft/min
	/ 3.281	25.24 m/min	19.72 m/min	88.84 m/min	76.02 m/min	38.8 m/min	27.21 m/min
	/ 26.82	0.941 mph	0.735 mph	3.312 mph	2.834 mph	1.447 mph	1.015 mph
	x1.609	1.514 km/h	1.183 km/h	5.33 km/h	4.561 km/h	2.328 km/h	1.633 km/h



Image by hyfs2012 from Pixabay

Category #		6d
Name		Raft / Canoe 6 table 4
Area m^2		14.86 m^2	16 m^2	16 m^2	16 m^2	16 m^2	16 m^2
Area sq ft		160	172.22	172.22	172.22	172.22	172.22
Width ft		12.5 ‘	4.4 ‘	5 ‘	8 ‘	12 ‘	13.12 ‘
Length ft		12.8 ‘	39.14 ‘	24.6 ‘	21.5275 ‘	14.35 ‘	13.1265 ‘
Min Rowers		3.855	4	4	4	4	4
Max Rowers		6	6	18	16	10	8
Logs / Row		30	15	15	20	36	40
Factor		x2.25	x2.25	x2.25	x2.25	x2.25	x2.25
Row Depth		0.417	0.293	1/3	0.4	1/3	0.328
Volume cu ft		150.12 cu ft	113.54 cu ft	129.17 cu ft	155 cu ft	129.17 cu ft	127.1 cu ft
Volume m^3 (/31.315)		4.794 m^3	3.626 m^3	4.125 m^3	4.95 m^3	4.125 m^3	4.06 m^3
Wt kg		2636.6 kg	1994.1 kg	2268.6 kg	2722.3 kg	2268.6 kg	2232.3 kg
Wt lt (/1016)		2.6 lt	1.963 lt	2.233 lt	2.68 lt	2.233 lt	2.2 lt
Max Pass		308	332.44	308.44	312.44	324.44	328.44
Max Cargo kg		61 600 kg	66 488 kg	61 688 kg	62 488 kg	64 888 kg	65 688 kg
Max Cargo t (/907.2)		67.9 tons	73.29 tons	68 tons	68.88 tons	71.53 tons	72.41 tons
Max Cargo T		61.6 Tonnes	66.488 Tonnes	61.688 Tonnes	62.488 Tonnes	64.888 Tonnes	65.688 Tonnes
Spd Rowers		+21.45%	+20%	+140%	+120%	+60%	+40%
Spd Width		-41.08%	-42.62%	-73.82%	-69.6%	-55.02%	-49.21%
Spd Wt		-9.8% – -60.3%	-9.8% – -60.7%	-15.8% – -60.3%	-15.2% – -60.4%	-12.6% – -60.6%	-11.4% – -60.7%
100+Tot Mod		70.57% – 20.07%	67.58% – 16.68%	150.38% – 105.88%	135.2% – 90%	92.38% – 44.38%	79.39% – 30.09%
Max Spd	x264	186.3 ft/min	178.4 ft/min	397 ft/min	356.9 ft/min	243.9 ft/min	209.6 ft/min
	/ 3.281	56.79 m/min	54.38 m/min	121.01 m/min	108.8 m/min	74.34 m/min	63.89 m/min
	/ 26.82	2.117 mph	2.027 mph	4.511 mph	4.056 mph	2.771 mph	2.382 mph
	x1.609	3.407 km/h	3.263 km/h	7.26 km/h	6.527 km/h	4.46 km/h	3.833 km/h
Fully Loaded Spd	x264	53 ft/min	44 ft/min	279.5 ft/min	237.6 ft/min	117.2 ft/min	79.4 ft/min
	/ 3.281	16.15 m/min	13.42 m/min	85.2 m/min	72.42 m/min	35.71 m/min	24.21 m/min
	/ 26.82	0.602 mph	0.5 mph	3.176 mph	2.7 mph	1.331 mph	0.903 mph
	x1.609	0.969 km/h	0.805 km/h	5.112 km/h	4.345 km/h	2.143 km/h	1.453 km/h

4.6.4 Overloaded Rafts

(Actual Weight – Craft Weight – [19]) ^ 0.5 / 3 = % chance per hour of capsize.

1 in 3 capsizes are total, 2 in 3 are partial. For partial, roll d% / 2 to get the percentage of people / goods that end up in the water.

[8] x 1.25, round down = % chance of raft breakup in a partial capsize.
[8] x 2.5, round down = % chance of raft breakup in a total capsize.

4.6.5 Raft Breakup

If the capsize result indicates that the raft has broken up, here’s the procedure:

Roll d20 x 5. If you roll high, this is the % of the raft that survives the breakup ‘intact’. If you roll low, this is the % of the raft that is lost. If you roll close to the middle, choose as above; a second raft consisting of (result-10) per cent of the original also survives.

When assessing / describing the results, which are (essentially) one or two rafts with different configurations, think about the construction of the raft, as shown below:



Notches are basically cuts into the timbers , no more than half-way through and preferably less. Because logs tend to narrow at one end, the direction the narrow ends point alternates from end to end; this makes it more difficult to get the notches to line up, but this is critical to the structure of a raft.

Into the notch is placed a crossbeam – usually a 1/4 or 1/3 ‘wedge’ from another tree. This should fit pretty perfectly as a result of matching the angle of the wedges removed from the main structure.

Note that these are at right angles to the main logs of the raft. This matters.

Nails are then used to secure the crossbeam to each of the logs. Note that these nails are at right angles to both the main logs and the crossbeams, i.e. up and down. The more nearly true this is, the stronger the construction – but the reality is that they will almost always be at a slight angle, one way or another.

This design means that no matter which direction a force impacting the raft is coming from, there is something that is resisting it and distributing that force across the whole structure.



Water and sky derive from Message In A Bottle from Pixabay.

This side-view should not only make this a little clearer, but also shows how multiple rows of logs are joined and how the structural strength is compromised by hollowing out the lower logs – but it has to be done.

Notice how the notches are staggered so that no two nails should ever meet head-on, which would introduce additional points of weakness.

Damage by natural forces is going to proceed from the outside inwards. First, a crossbeam will come loose; second, one or two logs held by the crossbeam will break away; third, what’s left may break into two pieces.

People and cargo can easily be lost overboard, and that can be a good thing because two smaller rafts do not have the same capacity as a single larger one. However, it can also be catastrophic because the sides that initially break free? That’s where your rowers are, and your oars. You might be able to replace the first, but the second severely compromises your situation.

Crews should build these rafts like their lives depended on them – because they very well might.

4.6.6 Construction Time

Construction time is determined simply by working out how long each part of the task takes. For example:

• Find a suitable tree
• Saw down the base
• Saw off the unwanted crown
• Saw off any large limbs flush with the trunk
• Trim any smaller limbs
• Hollow the log if you are going to
• Carve any notches being very careful with measurements

Repeat for each log needed. Construct the crossbeams from an additional log. (You might think that if you’re using 90-degree wedges, you will get 4 of them per trunk. You won’t; you will get three and some leftover wood, because you need to be on the better side of the inevitable margin of error).

• Assemble the raft.
• Launch the raft.
• Stock the raft.
• Mount the raft.
• Navigate, Row the raft.

The diameter of the logs is obviously a critical question in terms of the first group of tasks – especially since the larger the tree-trunk, the larger any branches will be, relatively speaking.

Divide 550 x the (average) diameter of the tree trunk by the lift capability of the characters doing the work to get the base time for carrying each of the tasks. Then halve the result as the result is the number of half-hours it takes.

If the wood is denser than the average used, it will be stronger and heavier – so apply a fudge factor to allow for this (and don’t forget the impact on the raft specifications).

Some tree types will have bigger, stronger limbs than others – compare oak trees and pine trees for example. So you need another fudge factor for that.

Having the right tools makes a huge difference. If using ‘adequate’ replacements, double the work; if using ‘inadequate make-dos’ multiply it five-fold.

Hollowing out a tree trunk is a LOT of work. And external holes into the hollow have to be plugged, probably with a mixture of sawdust and wood sap. The usual method is to start at the thick end, set it alight while repeatedly moistening the parts that you don’t want to burn, and – as soon as it chars – digging out the part that’s burning to create a hollow. Set a fire within the hollow, and repeat – again and again. Then plug the end, possibly with a sawn-off tree cross-section.

Even under the best of circumstances, with the right tools, this takes the base time per foot of length to be hollowed.

Some tree saps are more volatile / flammable than others. This can speed the work but make it more dangerous and frustrating – Australian gum trees, for example, can explode when burned. So apply a relevant fudge factor for the tree type.

Beyond these guidelines, use your own best judgment. But note that a lot will depend on the scarcity of suitable timber. Emphasis on the word “suitable” – the trunk has to be considerably taller than the intended length of the raft. If not, the raft will have to be shorter.

It’s also worth noting that rafts are so inefficient as a means of cargo transport that only being marooned and having no other choice makes it viable. That’s a factor that’s been at the back of my mind throughout this section, and it should be in the back of your mind whenever rafts are discussed in-game, too.

But there are times when a raft is the best possible solution. When the knights need to transport both themselves and their horses to the scene of a confrontation in Edding’s “Tamuli” series, the only practical solution is for the Knights to ride on board ships with the horses on rafts that are either pushed or towed by the ships – the stories give the impression of pushing, but towing makes more sense. From memory, this action starts in book 2, The Shining Ones, and concludes in book 3, the hidden city, but don’t quote me on that!

Ultimately, it’s not up to the GM to decide when the PCs will take a raft to sea – it’s a choice that the PCs have to make. While he may be able to predict it as a possibility, there may be other solutions to the needs of the moment. The goal of this section of the series is to give the GM the tools that are needed to accommodate the choices made by the PCs.

4.6.7 A final word on Overloading Capacities

Done properly, this is a reasonable risk to take. Done improperly, it’s not.

Overloads in the form of consumables are – as a general rule – worth the risk, because those consumables will disappear over time, mitigating the risk – and avoiding the risk of running out of food (or, more importantly, potable water).

However, there are limits to this sort of thing, and the players and GM will need to be very wary of those limits.

How long it is going to take the characters to get somewhere where they can do better for themselves is a critical question. The Vector Sum rules are presented very early in this discussion, and in considerable detail, for a reason.

I should also emphasize that threats are magnified several-fold if you are stuck on a raft. Think about a shark or two – one need only nudge the raft until it capsizes, even if it isn’t damaged, for lunch to end up in the water. A single shark can be as menacing as a while school of them would be in a ship, and then some.

Rafts may not be anyone’s first choice of seagoing vessel – but they are sometimes the necessary choice.

4.7 Canoes etc

Canoes and small boats are basically rafts which trade dimensional constraints (inherent in the basic hull shape) for additional speed. They are often at the smaller end of the raft scale because they are essentially either a single hollowed out log or a wooden or metal frame with some material – leather or cloth – stretched over the frame and treated to make it waterproof.

The latter are a lot more delicate work to construct, while the former are simpler, requiring less expertise, but involving more manual labor.

4.7.1 Proportions

All small boats have the proportions of either 1-to-x or 1.5 to X, where X is always at least twice the base of the ratio.

So 1:2 is valid. So are 1:3, 1:4, 1:5, and so on, even up to 1:12 or 1:14 – which violates the basic dimension restrictions for rafts. Some rowboats use 1.5 as the base of the ratio, 1.5:3 is obviously the same as 1:2, but 1.5:4 or 1.5:5 are also legitimate. And again, you can go all the way up to something like 1.5:16 or more.

4.7.2 Frontal Dimension

Boats usually taper to a point at the front, just like ships, making this a non-existent dimension in reality, but for the purposes of construction and calculation, the width at the front is assumed to be the same as the width of the boat at it’s widest point, and the area is assumed to be that of the resulting rectangle.

Unlike rafts, however, the frontal dimension can be as small as 1′.

Each rower or oarsman is assumed to occupy a space, sitting down, of 1′ x 2′. That means that the narrowest vessels in this category only support rowers in a single line, and not pairs of rowers.

However, if the craft is 2′ or more wide, 2 rowers can operate side-by side – and you can actually have extremely wide vessels with up to three oarsmen on each side per 2′ of length.

Because of the narrowing of the hulls, the front 2′ of hull are not permitted to have rowers, however.

Examples of the combinations that are possible when all these restrictions are taken into account are shown below.



Figure 1 illustrates the point made about shape – the system assumes that the three shapes are equivalent, and then offsets the error with a higher base speed for shapes 2 and 3. What matters are the dimensions of width and length.

Figure 2 shows a 1;:5 ratio boat with 1′ width. Because of the (invisible) tapering of the hull, there is no room for a rower in the front 2′. That leaves 3′ of room for rowers – but since each occupies 1′ x 2′ of space, there can be just one rower. That leaves 1′ of space at the back that could be used for cargo or for one person standing up. The one rower could either use a small oar that they moved from side to side with each stroke, or two oars that they employed simultaneously.

Figure 2a shows a 6:1 ratio boat with 1′ of width, showing that this creates enough room for a second rower.

Figure 3 keeps the same ratio of width to length, but doubles the width to 2′ – enough for rowers to operate in pairs side-by-side. This means that 8 rowers can be operating, or 4 rowers with 4 resting at any given time.

Figure 4 doubles the width of the craft without increasing it’s length. Now, you can have 16 rowers – or 8 rowers with 8 resting – or 8 rowers and 4 passengers (the raft configuration). There are multiple possible 8-rowers-and-8-resting configurations, as well, but they all amount to the same thing in within the game mechanics.

Not shown (there wasn’t enough room) is a 1.5′ x 10′ ratio – basically, Figure 3 with an extra half-rower’s width. This requires the rowers to be staggered, but leaves room next to each rower for a small amount of possessions or cargo.

There are other possibilities as well – Figure 3 with 4 rowers and cargo / passengers in positions 3, 4, 7, and 8, or with someone manning a tiller at the back with a passenger / cargo beside them.

4.7.3 Base Speed

Just calculate the speed of the vessel as though it were a raft, using the correct number of rowers (and remember that on a raft, these are all configured in pairs).

Then adjust the base speed from 3 mph as follows:

Base Speed = 1/2 x ([Length / Width] – 1)

The raft system then spits out correct answers for these small boats, taking into effect everything that matters..

It’s that simple.

Thuings I didn’t get to do / finish:

(1) An example in the raft generator, worked step-by-step. That will have to wait until I edit all this into an e-book.

(2) A spreadsheet that does it all for you. What, you thought I calculated all those table entries manually? No chance! But it needs some tidying up before it’s ready for anyone else to use. Depending on how quickly the rest of the next part flows (and it’s part-done already), I may or may not get time to finish it for a bonus freebie. If I can, I will – I would rather do it while it’s still fresh in my head.

Next time, the seriously maritime: Ships of many shapes and sizes, plus exotic modes of transport, to wrap up this chapter of Trade In Fantasy.