Saturday, June 23, 2012

Why does Urban Developments Matter?

People who read Board Enterprises books will likely remember that I ask the question “So what?” quite often. I think it’s important. Why did you just read three paragraphs about wheat farms and millers? Because bread is the basis of the entire economy. That’s why it matters. So we wrote and published Urban Developments. Why does it matter? So what? First, it really is one of the most efficient ways to design cities (or towns, villages, hamlets, etc.) from the 10,000’ level. You can make them quicker, but you won’t know what you need to run them off the cuff. But in the back of the book is a huge amount of math. One of the main things it computes is: How much land do the farms needed by the city take up? For example, a city of 25,000 people requires in or around 725 square miles of land to feed it and the farmers. That means that the circle of “influence” around the town is out to about 15ish miles. I doubt anyone will really have an issue with that. But that’s only 25K folks in the city. Let’s go to 100,000 people. Does your world have any 100K people cities? Now you’re talking a circle that goes in every direction out for the city for 30 miles. (30.4 actually). What if the city is on the shore of the ocean? Well, some of the food will come from fishing, but that 30 mile circle is going to get a lot bigger. Let me give a specific example. Brinston is a coastal city and has 800,000 people in it. That means that they would need 86 miles in all directions to feed those folks (more than 23,000 square miles). But the elven forests are 20 miles north of the city. And the South Pot Mountains start about 50 miles south of the city. And obviously the ocean is parked right there, west of the city. So the farmlands that support the city of Brinston follow the river east for a lot more than 80 miles. In fact the food to sustain this great city is imported from all over the place. So what? Brinston is the center of trade throughout the world. So what if they need to import their food? Well, what if they get attacked? The barbarians didn’t wander up to Rome and sack it. They first messed with the capital of the greatest empire’s food. Read up on the Vandals if you want more details. With Brinston’s food supply stretched so far along the river, if someone wanted to besiege the city, they just need to stop the river traffic. What if eager nobles start cutting into the elven forests in order to plant more crops? Wow- can you say international incident, and all over a couple hundred trees. We touch on this in the book, but think about this one: OK, so the land required to feed the people extends out at least 60 miles in all directions (that’s feed, not clothe, etc). An ox cart moves at 15-20 miles a day (on a good road). That means that the majority of the food is coming from more than a day’s journey out, and some of it is at least three days on a cart before it hits the marketplace. Some things you can explain. You can lead livestock into the city and butcher them there. But you can’t have dairies in the city. Well, you can, but then you have to bring the feed to them, and there are a bunch of other issues. You probably can’t have orchards in the city. What’s my point? Well, it’s that the city folks might not have the slightest clue what fresh fruit is like. They’re eating potatoes and flour, maybe with some ham or salted beef, but they aren’t biting into a fresh peach. Even if they get peach preserves, they still don’t drink milk. Three day old milk - Do not include me on that one! We’ve just started to scratch the surface of the issues here. A lot more detail and explanation can be found in Urban Developments. We are also looking at developing a book that walks through the mundane and magical lives of people in a fantasy realm. It will get into a lot more of these types of things, but it isn’t going to be our next book. (Read, not likely 2012)


  1. That info is gold. However it does pose a bit of a quandry for me. I would love to run my homebrew setting through the numbers you've worked out and see just how badly it breaks and what consequences and/or changes result. The only (significant) obstacle for me is the imposing amount of math and effort all of this implies. Just how difficult would it be to put a setting through it's paces? Would it be work the effort?

  2. T formulas are set up so that you cn either do the math in about two minutes OR you can set up a spread sheet so you can dothe math instantaneously. The cool thing about both is that since the formulas are overly simplistic, you can change the assumptions if you want. One of the main assumptions is about fallow crops fields, and you can easily adjust for three field or two field rotations, for example. It isn't as difficult as it sounds!