Ask The GMs: Weather, Not Climate
How do you give your campaign realistic weather without overloading the GM with Admin tasks?
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Mike’s answer:
The problem:
Weather is never an easy subject. On its face, it looks simple, but let’s consider the real world that any game system would have to model. Weather is driven by Chaos Mathematics, which means that tiny changes can cascade into monumental consequences. A butterfly flaps its wings somewhere at the wrong place and time and you get different weather 2000 miles away and five days later. So the reality is difficult to reduce to a simple simulation, which is what you need for an RPG.
Of course, we’re not necessarily all that interested in accurately modelling real-world physics. It’s a game, and simulation verisimilitude can and should be sacrificed in the interests of playability as necessary. But even then, there are other problems that make weather a difficult subject to handle well.
Weather is a non-static system, where one day’s weather influences, but does not dictate, what happens tomorrow. That means keeping track of day-to-day events and ensuring that the trend, over many game seasons, reflects the climate that has been deemed by the GM to be appropriate to the geography in question, while still providing the degree of randomness that’s necessary to making it feel real.
So, with that in mind, here is a quick review of the different solutions I have used over the years, with their pros and cons:
1982: My First Weather System
One of the earliest House rules I introduced into the first campaigns I GM’d was a weather system. Each geographic region would be assigned a climatic model that specified seasonal baselines for temperature mean (both day and night), temperature variability, rainfall likelyhood, rainfall intensity, rainfall duration, and so on. A couple of die rolls then gave a random value within the indicated range of statistically likely results, with a slight chance of an extreme weather result. What made the system a little different to others that I had seen in The Dragon and in other campaigns and rules systems was that each die roll provided a modifier to the results of other die rolls relating to that particular day’s weather, and another to the rolls for tomorrow’s weather, and another to the weather for the day after, and one to the season overall. Some of the these modifiers acted to exaggerate the more extreme results in severity and likelyhood, some to bring it back towards the climatic baseline, and some introduced long-term biases. There was even a threshold limit that would indicate a climatic shift for the geographic region.
This system, with two competing feedback loops pushing weather toward extremes and toward conformity, respectively, worked a treat as a weather simulation system, but it was a lot of bookkeeping and a lot of work to maintain. And it wasn’t properly documented. So when there was a critical failure of the real-world weather around me, and the rules were reduced to soggy woodpulp, it was abandoned.
What happened? Well, it’s not really relevant, but I’m sure you won’t let me out of the building without an explanation so, in brief: I was unemployed at the time, and could not afford public transport both to and from gaming. One way, yes, but not the round trip. So I used to walk the 16km home each Saturday night, with a heavy backpack of rulebooks and notes, rain or shine, hot or cold. It took me between 4 and 6½ hours depending on conditions and load. So, one summer’s night, I got caught out in the open by a seasonal but unexpected storm which ripped my umbrella to shreds and thoroughly soaked anything in my non-waterproof backpack that wasn’t protected. The weather tables bore the brunt of it, but protected everything else, so I couldn’t (and can’t) complain too much.
This was in early 1982. In modern times, with spreadsheets and javascript-enabled web pages and the like, it would be relatively easy to take most of the work out of using the system, so I now regret losing the game mechanics that I had worked out more than I did at the time. But anyway, that’s what happened.
1983-2002: The Real World
For the next many-some years I largely ignored the question, or took whatever was happening outside the window, seasonally adjusted. A cold, wet, day in summer became a cold, wet day (or heavy snow day, if appropriate) in winter, as necessary. A simple solution, but one that my players quickly cottoned onto and started to take advantage of.
So I started inverting the pattern – a cold, wet day became a mild, dry day in winter. That took a little while longer for them to figure out, because sometimes I was lazy and didn’t swap things around. But within a few months, they could get it right 90% of the time.
So then I started using tomorrow’s forecast as today’s weather. That worked for 2 years. Then I started inverting tomorrow’s forecast – another year, but by now it had become a game-within-a-game to them, a challenge to get them warmed up for game time.
When they started getting too good at that, my TORG campaign was just getting underway. I decided to start using the weather as it was on the day I first drafted the scenario as a basis – whether it was a day, a week, a month, or six months in the past.
These techniques all had the additional advantage that I didn’t have to tie the daily weather to a specific season, just document conditions relative to whatever I was expecting.
That worked for more than 5 years, until that campaign came to an end, and I found that when starting a new campaign, the system didn’t confer enough variation from day to day, because so many scenarios when a campaign are starting out are gestated simultaneously, or close to it. So it was back to the drawing board, and a search for a new solution.
2003: Weathergen 2.1
In 2003, when I started running my original Fumanor Campaign, I came across an online program called Weathergen. You specified the climate and the season and it generated a full month’s weather for you as a web page. It was not as sophisticated as the customised solution that I had developed years earlier, but it was a lot less work, and I used it exclusively for that campaign. I would still be using to this day if it were still available, but it’s not. When I went to generate weather for the opening session of the One Faith Fumanor campaign, I got a 404 – website not found.
2007: The Quest Begins
So I started searching all over the place for alternatives. There are weather generation software packages out there – a Google search for “+RPG +Weather +Generator” finds 32,800 results – and I’ve downloaded a heap of them to trial. None of the ones that I’ve tried have quite satisfied me, but that hasn’t bothered me, because I’ve found a new solution based on modern technology.
2008-9: The Internet Beckons
With the advent and modern ubiquity of the internet, many countries have official websites devoted to their bureaus and departments of meteorology. These not only provide current forecasts, they also frequently have historical information. Supplementing these are the many newspapers who have online archives, which sometimes include weather forecasts. So these days, I draw up a shortlist of “terrestrial equivalent” locations and use the appropriate forecasts for the season. It can require a little planning ahead – if, for example, I know that the PCs are about to be in an Athens-like climate in summer, and it’s currently winter there, then I really need the forecasts from six months ago; there are only two ways to get those, either through an archive of some sort, or by collecting the information that I need six months in advance.
Derailing The Plot Train
That need obviously tends to encourage plot trains, if the GM doesn’t take precautions. To guard against that, I try to look not at where I expect the PCs to be, but at a subset of places they might be and prepare accordingly. After all, if I gather information that I turn out not to need, I can always put it in a drawer until I DO need it. I also like to declare a secondary source in the other hemisphere if I can find one that can be used if I need something unexpected at short notice. If I have to, I can take a semi-appropriate forecast and tweak it to my needs – I might take temperatures from New York and rainfall from Sydney to simulate an area that is bone-chillingly cold in winter but receives only widely-dispersed heavy snowfalls.
Ultimately, all you need is a starting point for inspiration and the rest can be faked.
Johnn’s answer:
You ask a great question, because weather in RPGs is a chronic under-achiever as a game element (pun not intended). I agree with Mike’s advice. Here are a few additional thoughts:
Build Your Weather a Year in Advance
If the location of the story is going to be fairly predictable, then determine your weather a year in advance, or for as long as you think PCs will be in the region. (I once calculated weather for a whole decade because I was GMing a home base campaign.) This not only gives you an answer for every day of the campaign for a long period of time, but it helps you do this bit of campaign planning in one short sitting.
If the location isn’t predictable, you’ll need to create weather on a shorter term basis, or possibly mid-session.
Weather Should Affect Gameplay
Make the weather affect the game. How does it impact the PCs? How does it impact their foes, locations, encounters, and plot points? If you’re going to put thought and effort into generating weather, then put it to use during encounters and situations.
- Weather for pure flavour is great and is a minimum requirement. Use weather as another way to provide detail and description. Yesterday the smithy was where the PCs dropped off gear for repairs. Today it’s a wet and cold place because a chill wind is blowing rain under the awning and into the work area, and wide streams of water flowing off buildings and through the middle of streets makes everyone clutch capes and hoods tightly as they dash between places, leaving no room for identification, much less chatter.
- It also is a good tool for generating hazards and boons. Consider the risks of being cold and wet, the benefit of having the wind at your back, and the boon of clear skies for direction. As a bonus, weather can be dropped anywhere outside and provides temporary dangers to make common routes interesting again.
- Game mechanics for weather effects are good too, for some games, such as D&D. They can reward character building choices (such as outdoor skills). They can also present the group with interesting options. Is heavy rain coming? If so, should they chance the valley to shave a day off travel time, or take the ridge to avoid flooding, landslides, and other dangers?
So, while you’ve requested realistic weather, please do consider in-game consequences your system of choice presents to characters, encounters, adventures, and campaigns.
Use Earth Patterns
Here are some additional resources to add to Mike’s advice on using real-world weather. (By the way Mike, great tip of basing game weather on the weather currently outside.)
- Roleplaying Tips Issue #237 offered this historical weather website: http://www.wunderground.com/
- And Issue #156 featured several Earth weather links.
- In Issue #128 a reader suggests using a Farmer’s Almanac for RPG weather, and Google has many options for online Farmer’s Almanacs.
Use Supernatural Weather to Liven Things Up
If your setting permits, be sure to add weird, extreme, supernatural, or magical weather to your calendar. Such weather adds a lot of storytelling potential to campaigns, keeps the players on their toes, and gives you interesting new encounter backdrops.
Random weather Table
Note that Roleplaying Tips reader Rick Heron devised a random weather table for his campaign that you can download and try out.
The Weather Track
To borrow from D&D 4E mechanics for a minute, how about building a weather track? The thing with many weather generators is they do not take into account season or duration. You could easily build weather tracks per season, or even per month, to provide daily patterns that seem realistic to your players.
And duration is a feature often overlooked by generators. One day it’s sunny, the next there’s a storm, the third day is cold, and the fourth is stormy again. The weather feels random because it bounces around so much at the whim.
I’ve lived in Vancouver, BC where the weather arrives and lingers forever, like a relative who can’t take a hint. Last year I noticed Vancouver set a record for over a month of getting rain every day! Whereas my current home, in Edmonton, sees the weather change quickly, and some days hourly.
Using the D&D 4E track system (ala disease and poisons) lets you mimic a weather system approaching and either settling in or clearing out. Instead of a disease, it’s a weather event. Each day, or hour, make a roll to see if the event strengthens, stays the same, or weakens.
Complement the weather track with a random table of possible events, weighted by chance of occuring in any particular month. Don’t forget to add supernatural events. For each day, roll on the table, and if a weather event occurs, switch to the monthly or seasonal weather track.
In addition, for each month in your game calendar, set a default day. This day represents normal temperature, precipitation, wind, sunrise time, and sunset time for that time of year. When a weather event isn’t triggered, or when one clears up and another hasn’t triggered, the weather reverts to the default day for the current month.
Final Thought
If I had to choose one method over anything else, it would be to generate a year’s weather in advance. I would use a generator or do it by hand, but with a forecast in place, you can smooth out any unbelievable anomalies, change mid-game if desired, and re-use for future years (another tip for another day) and future campaigns.
Cheers,
Johnn
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April 7th, 2009 at 12:42 am
Great answers! I truly admire the thought and time you put into your answers.
Another possibility for the lazy and/or unprepared DM (who me?) is the online random weather generator Dire Press have on their website (http://direpress.bin.sh/tools/weather.html). It generates random weather for one day based on season and three climate alternatives and also has an option for supernatural weather effects.
I found this generator via Google when one of my players caught me off guard during a gaming session asking what the weather was like, and since then it has saved me several more times.
The advantage of this generator is that you can produce random weather on the spur if needed, and it also includes the effects weather has on certain skill checks (spot, search, listen), ranged attacks, mobility, and light sources. These effects are tailored for Dungeons and Dragons, but they are easily adapted to fit other game systems.
The downside is that it only generates weather for one day, and thus can produce very different results from day to day. While this can be okay on short term basis, it will deminish the credibility of your game world over time.
The compromise I’ve found is to generate results for one month (in the case of my world 28 days) at a time, and then hand tailor any results I feel don’t fit. This may involve rearranging some of the results and completely regenerating weather for some days. The end result is a pretty consistent weather system I feel fits my campaign, with just enough randomness to keep it interesting.
Tor Martin Pedersen’s last blog post..Players and Dungeon Masters
April 7th, 2009 at 1:19 am
Lovely weat……post! This covers alot of ground on the subject and it has shine on a few spots that needs to be taken into consideration when using weather in the game.
Don’t mind me showering you with praises like this.
Questing GM’s last blog post..Word of Wizards – Tell Us What You Think!
April 7th, 2009 at 8:39 am
If you’re interested in generating a randomized model, you can do a Markov chain.
Set a probability that it rains tomorrow if it rains today – say, 40%, a probability that it is sunny tomorrow if it rains today, say 55%, and a probability that it snows tomorrow if it rains today, 5%. Do the same for if it’s sunny or if it’s snowing, and maybe alter them around according to season – more likely to be snowy tomorrow regardless if it’s winter time.
That way you don’t have to think too hard about it.
April 7th, 2009 at 9:12 am
@Tor: Thanks for the link. Useful contribution.
@Questing GM: Thanks from both of us for the kind words!
@BGG: That was the foundation of the original weather tables that I put together back in the early 80s. But instead of drawing a line through the seasons, there were progressive modifiers so that you couldn’t really say where one ended and the next began, and so that if you had rain on two successive days it was a little less likely that you’ld have rain on the third, and so on. I don’t know Markov chains from fence-link chains, but I did understand the concept of feedback loops, both positive and negative, so that was what I used.
April 7th, 2009 at 11:41 am
Without intentional advertising, I’ll still recommend dm genie for this purpose, it’s very unfortunate that dm genie’s creator has stopped any further updates a while ago, but the tool still has plenty of resources for all staying with 3.5/Pathfinder… It’s just great for timekeeping and has an integrated weather generator that in my experience works best and is able to satisfy the need of most dungeonmasters.
That said, thanks for the headsup on weather. I can only second the opinion on supernatural weather. Make sure you don’t use this too often – but it tends to create an exceptional atmosphere when used with good preparation. (at least my players are very susceptible).
TheLemming’s last blog post..Rashemen and Beyond (Session 7 / Session 2 with a Lemming as DM)
April 8th, 2009 at 1:09 am
Wither the weather?
I feel I’m somehow less than respectful for the excellent quality of the above words for saying this, but I feel that my point of view may also have merit for some so I’ll present my philosophy on weather/climate in RPGs.
Adding massive amounts of detail to your game-world can be great. It can also be a time-sink.
Basically, for me, the climate is “background” information to add flavour text in my description of the gaming world, nice, but I don’t spend too much time on it. A general and brief mention at the beginning of each scenario helps get the players “into” their roles. The weather is what hits players in the face if I decide to include it. The decision is based on my objectives for the scenario: if the team is in a hostile environment, and logically overcoming the hazards of heat/cold/rain/storm/waves, etc is a part of the thrill, then yes I’ll include it. If I feel I have a short space of time that can profitably be used to spice up the “living, breathing” feeling of the world with a short burst of unusual weather, ditto. Giving players a chance to shine (show off their characters skills and gain the applause of their peers) is also worthy of our gaming time.
Otherwise it gets the “hand-wave” treatment of a brief description and we move on to something else (see Johnn’s recent articles on “hand-waving” past the (ahem) unimportant stuff).
The overriding criteria for including weather/climate thus break down into two aids towards two sub-objectives.
Sub-objective one : the GM presents his world in terms that helps the players visualise it easily.
Sub-objective two : elements that present challenges for the player characters to overcome, and chances for them to shine.
The over-arching objective is, of course, “All for fun, and fun for all!”
So, I won’t try to kill off players with the weather, but I might challenge them to survive under difficult circumstances… occasionally. Being informed that your character has pneumonia once is an interesting even potentially enriching gaming experience. Five times in a row and it’s just a drag….
Note that this implies that I’ve decided in advance the climate of the various regions of the world (based on geographical principles, during the world creation process) and all local variations are decided on a case-by-case basis when I’m in the throes of the *scenario* creation process. Should I be using one of the game systems I’ve invented, this is also the time to check over my rules decisions for how to handle the effects of the weather on the players. Again, I follow what to me is an important principle: “Keep It Simple”. You’re not really obliged to print out bundles of weather tables and roll on them in real-time in-game (I’d automate this under excel anyway :) ). A few simple preparations and decisions ahead of time save you tons of delays during you precious game-time. You only need to describe what is relevant to the gaming party, anyway…
So, a basic principles recap:
Keep It Simple (Prior Prep helps!)
All for fun, and Fun for All!
If it *aids* you, include it:
Climate helps present your world
Weather is a tactical element to eventually spice up your scenarios.
…. otherwise, mention it briefly and move on to better stuff.
April 8th, 2009 at 3:14 am
I couldn’t agree more with what you’ve said, Loz. But the problem is to be offer up a realistic variety of weather even when you only ‘handwave’ at it. That’s what our article was primarily intended to address.
April 8th, 2009 at 5:13 am
“Realistic” and “fantasy”… Perhaps “plausible” would be a better word? Given the requirement of Suspension of Disbelief needed to fully enjoy RPGs, I see your point. Too many irregular spasms of weather change would tend to jolt players out of their mind-set (“Huh? What…?”), and spoiling the fun for everybody. Hence the seeking for ways to randomly generate specific weather events within a given subset of *plausible* climactic possibilities. My counter-point would be : If you’re into dice-rolling on tables, and sub-tables, and sub-sub-tables (the Rolemaster system lumbers to mind here….) then go for it. My idea was to propose a much less onerous method for those (like myself) who dislike having to constantly handle this level of detail. “Onerous” being of course somewhat subjective… As a GM you’re there to enjoy yourself as well : if this is too much of a time-sink and/or harshing your enjoyment, then back off to a lesser level of detail/commitment.
Minor point : I feel that randomly ceding control of this kind of decision to a program, may leave you stuck with random unpleasant consequences (“A level 5 superstorm lasting four days?!. Curses… Now there’s *no* way the Characters can get to Badguyopolis in time to prevent the Ritual of Apocalypticaly Bad Consequences…”). The possibility of tweaking the output would therefore be a very desirable trait and as such programs proposing this option should be preferred.
April 8th, 2009 at 8:45 am
Good comments, everyone.
@Loz: I agree, it comes down to priority and GMing style. A GM should do the work first that makes the game most fun to play for him and his players.
April 9th, 2009 at 7:30 pm
Johnn,
I really like your suggestion how to turn an underachiever element such as weather into a powerful flavor piece. While I would also agree that GM/player style and preference should determine the how much time we meddle on issues of weather, I think that your sample flavor text for the sodden city shows how something as simple as steady rain fall can really change the aural landscape of a village – I could see weather as a great tool for the GM to ‘get the most’ out of the players’ senses and imagination with minimal effort and no ‘new’ material that wasn’t on the fly.
WarlordGDX’s last blog post..The Warpath: Is Hasbro/Wizards of the Coast Smoking Crack?
April 10th, 2009 at 10:56 am
@WarlordGDX: “how to turn an underachiever element such as weather into a powerful flavor piece” – that’s a nice way of putting it. Thanks!
April 15th, 2009 at 11:05 pm
[…] a sunnier note, Johnn and Mike over at Campaign Mastery put up an interesting piece about weather last week. The pair offer several different realistic weather models and random generators. It is a […]
June 9th, 2010 at 2:35 am
I really like your suggestion for achieving the flavour element of weather.
Thanks for sharing :)
.-= Desiree Zara´s last blog ..Jun 8, Virtual Bookkeeper =-.
January 7th, 2011 at 8:44 pm
http://www.serg.soton.ac.uk/ccworldweathergen/index.html
Here is a program for doing weather made by the IPCC