Last-Minute GM: City Street Mapping Options

I was thinking about how to handle city street maps after reading a blogpost I can no longer find concerning improv streetcrawls, where you only pre-generate the major streets and save side streets and alley ways for when you actually need them. But what about those major streets? How do you generate those, if you don’t feel like drawing them out?

There’s a couple ways it could be done:

• Use the Sketchbox Dice Tool: The Quarters roll has you roll a d6 with pips for every town quarter (or every city district.) The pips represent neighborhoods, so the spaces between the pips represent streets.
• Use leximorphs (letter-shapes): Pick a word in some random way, or roll on the Random Random Table or equivalent for individual letters in each city district. Strokes in each letter represent streets.
• Use routes or “clock-paths”: This a new name for something I’ve described before: rolling several d12s and interpreting each as a clock direction (12 o’clock = North, 3 o’clock = East, etc.)

Option 1 generates some fairly grid-like streets that don’t feel very organic, although you can get a little less rigid if you are reading the orientation of the d6 as well as the number and placement of the pips. Option 2 is better for generating maze-like city maps, but needs extra info about orientation for each letter if you don’t want it to be too obvious.

However, I want to expand on Option 3. In a couple of my random wilderness posts, I talked about navigation by landmark and creating random routes from one point to another. This seems the best approach for a city with a more organic feel.

1. Start by defining the central features of each city quarter (the palace, the main temple or marketplace, etc.) Place those on your rough city map, perhaps using a roll on the Sketchbox Dice Tool as a guide to position.
2. Each pair of major features can potentially be connected by a major thoroughfare. Decide which ones, or roll 1d6 for each pair: 5+ = connection. These are the main streets of the city.
3. Each quarter contains five city districts, each of which will have a major landmark of some kind as its hub or central point: fountains, statues, unusual buildings, parks. Place these landmarks as you would place a central feature.
4. For major streets, first check if a major landmark is connected by a street to the next closest landmark (5+ on 1d6.) Then, roll 3d12 for each landmark for additional major streets, using the result as the clock direction. Only unique results on the d12 count, so triples mean one extra street instead of three.
5. City districts may also share major streets with neighboring districts (border streets) Roll 5d6 on the Sketchbox Dice Tool and treat any result of 5+ as a border street along the border indicated (north, south, east, west) on the tool.

This creates your city framework. What comes next depends on whether you are mapping one or more (or all) city districts beforehand or doing it as players explore. For the former, you would roll 1d6 for the minimum number of neighborhoods in each district and place those, using the existing streets as much as possible to define neighborhood borders, adding minor streets if necessary. Follow this by rolling 1d6 for the number of blocks in each district and arrange those as desired, separating blocks with more minor streets. The Town and City Block Tool can be used for building and alley way placement.

If you need to know the orientation of any border street or minor street, roll 2d12. Read each die as a clock direction for one endpoint, relative to the center of a block, neighborhood, or district. If this seems to make a street double back on itself, make it a curve. When a minor street would cross another street, roll 1d12 for another clock direction. If this result would double back, the minor street ends instead. Otherwise, it crosses the other street, possibly changing direction.

Mapping city districts as players explore would resemble techniques I described in various wilderness hexcrawl posts, but I will have to describe this later.

This work is licensed under a Creative Commons
Attribution-NonCommercial-ShareAlike 4.0
International
(CC BY-NC-SA 4.0) license.