Despite how dull that seems, I think that some of what I found may be interesting!
D&D demographics are post-industrial
D&D and derived d20 fantasy games give us a bunch of settlement types / names to work with, as I mentioned last time:
- Metropolis, large city, small city, large town, small town, village, hamlet, thorp
Notice that we only have three types of rural settlement, and 5 types of urban.
When I studied urban development and settlement theories at school, one of the key theories was Christaller's central place theory. (I suspect I remember it so well through a combination of this topic being one that my father helped me understand by getting me to explain it to him, and the fact that it lays out settlements on a hex grid...)
I'll not bore you with all the details, but simply put, he proposed (and then to some extent proved in the real world) that settlements grow according to their place in a hierarchy - the settlements that provide the most important or unique services grow largest and influence a wider area, while those with common services are less influential and grow less. That is: there are many farms (small settlements), but only a few seats of government (probably in a metropolis).
You can look up more details, of course, but the practical issue I want to talk about here is that he said that each order of settlement would be served by on average six of the next lower order: a town would be surrounded by six villages, roughly equidistant, and those villages by six hamlets, each, and so on.
When I applied this idea to the categories from the d20 fantasy rules, I found that for 1 metropolis, I had:
- 6 large cities,
- 36 small cities,
- 216 large towns,
- 1 296 small towns,
- 7 776 villages,
- 46 656 hamlets and ...
- 279 936 thorps
- metropolis, 25000+
- large cities, 10001 - 25000
- small cities, 5001 - 10000
- large towns, 2001 - 5000
- small towns, 201 - 2000
- villages, 61 - 200
- hamlets, 21 - 60
- thorps, 20 or fewer
When I put those population data into my numbers of settlements, I got the following average:
- metropolis, 37500
- large cities, 105 003
- small cities, 270 018
- large towns, 756 108
- small towns, 1 426 248
- villages, 1 014 768
- hamlets, 1 889 568
- thorps, 5 598 720 or fewer
That gave me a total urban population of 2,594,877, total rural population of 8,503,056 (rural being anything smaller than a town), in a total population of 11,097,933. In other words, a 23.4% urban population.
(This is of course based on a relatively small "metropolis" - bigger metropolises will tip the balance even further.)
Now, when I looked at real world data, I found that this level of urbanisation only started after the industrial revolution. Before that, there just weren't the transport links to make massive urban centres sustainable. We couldn't get fresh food to the city markets fast enough to support city dwellers on a large scale.
Prior to the industrial revolution, the split of urban to rural population was more like 1%, rising to 10% over the first hundred years of the agricultural revolution and early industrial era.
A 23% urban population is more like the level we saw in Europe around the mid to late Victorian era.
Urban sprawls need magic or technology
So it seems that the top heavy set of settlements that the standard rules give us means that the d20 fantasy setting is out of kilter with its usual pseudo-medieval idyll. It's a more modern balance, based on a time of technological advancement, railways and mechanised farming.
Of course, maybe a wizard did it.
In some high fantasy settings, magic can take the place of industrialisation, so that the early industrial or even modern distribution might be appropriate. Consider the level of magic, and the ability to rapidly travel. Food production might even be magically achieved. It might even be possible to exceed our real-world modern level of urbanisation.
But I think it's important that if you decide to have a wizard do it, you know what they have to do.
Next: Population density
Back to my intended schedule, in which I put some of this research into practice.