{"id":21200,"date":"2017-10-24T00:30:37","date_gmt":"2017-10-23T13:30:37","guid":{"rendered":"http:\/\/www.campaignmastery.com\/blog\/?p=21200"},"modified":"2017-10-19T14:32:17","modified_gmt":"2017-10-19T03:32:17","slug":"the-impact-of-urban-migration","status":"publish","type":"post","link":"https:\/\/www.campaignmastery.com\/blog\/the-impact-of-urban-migration\/","title":{"rendered":"The Impact Of Urban Migration On Fantasy Games"},"content":{"rendered":"
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Image provided by FreeImages.com \/ Gabor Palla<\/p><\/div>\n

Documentaries are supposed to educate and enlighten, to Document<\/em> and explain.<\/em> There is little so irritating as a documentary that ignores or commits errors in basic facts to present a myopic, distorted, or one-sided view that provides only half the story.<\/p>\n

This evening I started watching just such a documentary. One segment was discussing the great migration of humanity from rural to an urban setting, and it made a number of points worth recapitulating and interpreting from a fantasy RPG perspective. But then it committed a vital sin of omission of the type described above, and from that point on, became increasingly unwatchable as irritation over the fact tainted the experience.<\/p>\n

This article will aim to correct that, and point out the true story. It will veer this way and that in the course of examining its subject matter, but always with the goal of helping fantasy GMs more accurately visualize their fantasy settings and the infrastructure needed to make them viable and believable.<\/p>\n

Static Until About 1800<\/h3>\n

We’re so used to a booming urban population that it requires a profound adjustment in our thought processes to appreciate the fact that cities were rare.<\/p>\n

Until about 1800, only 10% (at most) of the population resided in an urban community of any<\/em> size, and between 9\/10ths and 99\/100ths of those were in small communities of no more than a few hundred people. A city of half-a-million was overwhelmingly extreme and improbably, and only the largest in the world could even approach that number. London at this time had not even hit the 1,000,000 mark.<\/p>\n

Most of the population was rural, living on the land in what were essentially extended family units, frequently in the employ or service of a landowner.<\/p>\n

It was the steam engine that changed this situation; it made factories possible, and factories provided employment, while at the same time, the steam engine made it possible for fewer laborers to produce the same or greater quantities of food more efficiently. (The documentary emphasized the first half of that statement while completely ignoring the second, and that was its great faux pas).<\/p>\n

And food supplies define the size of a city, far more than disease or trade or anything else. If more food can’t be brought in, the city can’t grow, and if it does, the excess population will quickly starve.<\/p>\n

A plague that wiped out 1\/3 of the urban population would be a dreadful one indeed – worse than the Black Death – but, if adequate nutrition is available, those numbers would be replaced in but a single generation.<\/p>\n

It was not until the steam revolution that it became possible to bring in sufficient food for a city to really grow in size. And, even then, it was not until 2016 that – for the first time ever – there were more people living in urban communities of noteworthy size<\/em> than there were living in a rural setting, distributed and dispersed.<\/p>\n

The economics of City Populations<\/h3>\n

Let’s say – and I don’t have access to the correct figures – that the typical well-fed individual in a medieval society consumes about 4lb of food per day, the adequately-nourished half that, and the ragged underclass, half that again.<\/p>\n

If you have a population of 300,000, of whom 20% are adequately fed, and 3% are well-fed, that leaves about 77% at the edge of starvation. In fact, about 2\/3 of this number would be<\/em> starving most of the time, though they would all gain sufficient food to stave off death – often just in time. That’s the way populations work.<\/p>\n

So that’s 60,000 getting 2lb of food a day, 9,000 getting 4lb, 77,000 getting 1lb, and 154,000 who average 0.3 lb overall by going hungry most of the time but getting 1lb of food every 2-4 days.<\/p>\n

Multiply those food consumptions out, and you get 120,000lb + 36,000lb + 77,000lb + 46,200lb = 279,200 lb per day, or about 101,908,000 lb per year. Near enough to 51,000 tons. If the average wagon can bring in 10 tons of food per trip, that’s 5,100 wagon-loads, or about 14 per day.<\/p>\n

An acre of wheat can produce perhaps 1 ton of wheat, 1\/2 of which has to be conserved to sew next year’s crop, and 30% of which at least<\/em> goes to the landowner and in various tithes and taxes. The remaining 20% feeds those who produce that acre of wheat.<\/p>\n

So those 10 tons going into the city are only 30% of what the land produces – and that’s with one of the most efficient crops. Animals and Fruit and other forms require more area to produce a given quantity of food, sometimes a lot more. So let’s assume that the average is actually going to be half as efficient (and that’s being generous) – to get to 10 tons of food, you need about 67 acres of agricultural land.<\/p>\n

Most land is not as productive as the best – let’s double the requirement to allow for that. 134 acres per 10 tons. And that makes no allowance for spoilage – let’s be generous and only add 50% for that. 200 acres per 10 tons. It also makes no allowance for bad years – so let’s add another 25% for that. 250 acres per 10 ton wagon-load.<\/p>\n

The more agricultural land you have, the greater the distance that food from the outlying areas has to travel, increasing the spoilage rate, but that can be countered by various forms of food preservation – pickling and smoking and what-have-you – before the food sets out, or at some convenient location part-way to the market.<\/p>\n

51,000 wagon-loads of 10 tons each thus represents the production of 12,750,000 acres, or about 19,922 square miles of average agricultural land – if the assumptions are correct. They aren’t of course; the real situation is far more complicated. That’s a radius of about 80 miles in all directions doing nothing but feed both itself and the city.<\/p>\n

Wait – that all assumes that the ruler of the city doesn’t have anyone else to whom he has to pay taxes and tithes. If 30% of what the city gets in has to go elsewhere, we’re talking roughly 18,215,000 acres, or 28,461 square miles, or 95.2 miles in every direction. There’s more than enough fuzziness about some of these guesstimates to say that everything in a radius of between 80 and 400 miles goes into feeding this one city.<\/p>\n

Yet, when most GMs picture a fantasy city, they think of something akin to the steam age cities in scale, a million people.<\/p>\n

Making Urban Populations Practical<\/h3>\n

There are four things that can make urban populations of the 300,000+ size practical in medieval terms. The first is that they will inevitably be situated wherever the best land is. The second is that they will be situated on rivers, and river transport can easily carry produce faster, farther, and in greater quantity than any wagon. The third is that most animals can be conveyed ‘on the hoof’ and slaughtered on arrival, or after a suitable period of replenishment; that’s a lot more efficient than carrying that much dead weight in food, even though it will take longer. And finally, most major cities will be on or near the coast, because the sea adds a third dimension to the land-use – depth.<\/p>\n

20 square miles of fishing area with a usable depth of 30′ is 6 times the size of 20 square miles that can only use the top 1′, even allowing for the fact that fish are not as densely-packed as vegetables can be. If a city can pull 1\/3 or half it’s food supply straight from the oceans, it needs to bring in that much less via other means.<\/p>\n

So you could have a city of 500,000 or 1,000,000 if you really want one. But the city has to support that level of population.<\/p>\n

And it may not be able to do so, indefinitely.<\/p>\n

Waste Disposal<\/h3>\n

It’s not a pretty subject, but it is an important one. Let’s say that 1\/3 of the food consumed becomes human waste. That’s 1\/3 of 51,000 tons a year, or 17,000 tons. It all has to go somewhere, and fantasy games are generally set in an era where sewerage processing is at its most primitive.<\/p>\n

That river comes in handy once again, because that’s where it will all go – regardless of the medical dangers that this might pose, or the long-term effects on the fishing off the coast.<\/p>\n

There must necessarily be an ongoing drive to improve the size and efficiency of the fishing fleet, because they will – over time – have to go further and further away from the city to find untainted food sources.<\/p>\n

But here, the power of pi-r-squared comes to the rescue. a semicircle of 10 miles radius would represent an area of about 157.08 square miles. If that gets fished out or tainted, how much further out would your fleet have to travel to maintain the same fishing area? Well, we’re talking about doubling the area, which means we have to multiply the radius by the square root of 2, which is 1.414 – so between ten and 14.14 miles out to sea, there is as much surface area as there is within that 10 mile radius. And that’s assuming that you don’t get any more depth to play with, which is also unlikely.<\/p>\n

That’s why improving the efficiency and effectiveness of the fishing industry is so important to a city achieving the sort of population scales that we’re talking about.<\/p>\n

An Arcane Economy<\/h3>\n

A lot of this restriction goes out the window if industrial-scale magic is a factor, but few GMs go down that path, especially when it comes to Agriculture. Most of us don’t like the implications – mass-produced wands of Cure Light Wounds, a Sleep<\/em> spell for every mugger, +1 swords on every street corner…. and even fewer are capable of working out the economic impact of all this. Certainly, the prices given in any game supplement don’t reflect this sort of industrial application of magic.<\/p>\n

But, if you truly want a steam-era London for your capital, approaching 5 million citizens, with its thousands of beggars and poor and criminals, that’s what you have to embrace.<\/p>\n

Even without going that far, any<\/em> enhancement to the agricultural productivity of a region
\n through the use of magic – Divine, Clerical, Druidic, or whatever – can have a profound impact. Contemplate, even given the rough-and-unreliable numbers used, the impact of turning away the worst storms, and especially those at the wrong times of year, or of being able to guarantee good rainfall each and every year. Or, equally, sparing crops from insects and blight.<\/p>\n

50% improvement means that 25% less land is needed to support a given population. 100% improvement – double the yields – means that half the land is needed. Or, to put it more appropriately, those would increase the size of the city population 25% and 50%, respectively, at a conservative estimate.<\/p>\n

The more such intervention is routine, the more viable it is to have vast cities. Another mathematical property of numeric functions becomes significant – the exponential growth function. Let’s say that you have three such factors, and each improves agricultural productivity by 50%. The same area would then support a city of 1.5 x 1.5 x 1.5 = 3.375 times the size. 300,000 becomes more than a million.<\/p>\n

If those three factors doubled production – still a relatively conservative estimate of what would be possible – the city swells to 2 x 2 x 2 times it’s size – 300,000 becomes 2.4 million.<\/p>\n

The question then becomes, “What are the social and economic adjustments that are required to make such improvements sustainable?”<\/p>\n

For the sake of argument, let’s suggest that all this is possible through Clerical Magic. The maximum number of acres that a given individual Cleric of a certain character level can care for would be carefully calculated, and there would be a massive industry set up to recruit, train, disperse, and support those Clerics.<\/p>\n

If you assume that half the increase in population – or 2\/3, or whatever seems reasonable – are employed in this manner, you can actually work backwards from the population increase in the cities to determine the number of acres each “practitioner” can support.<\/p>\n

Farmers would have no choice in the matter. If they refused this Divine Aid, their efficiency would be so poor relative to their neighbors that they would immediately fail to meet the quotas that were set up on the assumption of such aid; they would be taxed off the land, and the farm turned over to someone more…. enlightened.<\/p>\n

Social & Economic Dominoes<\/h3>\n

Ignoring entirely the question of magic for a moment, consider the impact of a city so dependent on its fishing fleet that a refusal to serve brings the city to its knees. Seamen would inevitably advance a step or two on the social ladder. They would be economically far more prosperous, able to afford nice homes. Law enforcement would almost certainly learn to look the other way when it came to minor offenses – like public drunkenness.<\/p>\n

Whatever the justification for the population is that you choose to employ, it will inevitably have social, economic, and even theological implications. These must also be considered carefully; while they may be secondary effects, they are nevertheless tangible differences that should be apparent to the players.<\/p>\n

The Size Of Fantasy Cities<\/h3>\n

As you can see, you can have cities of any size you desire in your fantasy world; but there is a necessity for cities to “justify” their sizes or the setting’s credibility will always limp. Your players might not know quite what is wrong, but something about the setup simply won’t seem right to them.<\/p>\n

Decide the size you want your cities to be, then set up the social, political, economic, and agricultural demands that are required to sustain cities of that size. And that’s all there is to it!<\/p>\n","protected":false},"excerpt":{"rendered":"

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