Procedurally generated content is a great way to prep for a game session in a hurry. Early D&D is rife with procedural rules; the earliest rulesets contained wandering monster tables for generating opponents and treasure tables to determine what phat loots those monsters have. The 1e DMG goes even farther by presenting a set of tables for generating a random dungeon map!
Computers, of course, are great for speedily generating random content. Community-oriented players have put up all sorts of free web applications for DMs. One such is “donjon”, a program that generates dungeon levels to your specifications in the blink of an eye. Not only can you set the parameters for how the place should be laid out, you can populate the place with monsters and treasures as well.
Computer-generated procedural content is not without flaws, of course. One is its lack of flexibility. If you’re sketching a dungeon map by making random rolls on a table, you’re free to diverge from the table results and interject your own ideas while drawing the map. A computer-generated map is not so flexible. Nonetheless, you can make changes—if you have the right software.
It was the day before the session and one of the players had decided to bite on a plot hook involving a group of Chaos worshippers congregating in the sewers of Glantri City. After a desultory attempt at sketching a map for a section of the city’s sewers, I decided to try an online map generator. After several minutes of fiddling with donjon and learning its settings, I came up with the map on the left. Since I wanted a short dungeon (as per David Bowman’s “One Page Dungeon”), I’d made a map with only a handful of rooms, but they were encircled by lots of winding tunnels to give that “lost in the sewers” vibe. (Click for a better view.)
But I was unsatisfied with the map as it was. It was too flat, too static. It also needed connections to the rest of the sewer system. So I started up Adobe Photoshop and started tweaking.
First, I filled in the sewer tunnels with gray to represent sewage. Several rooms and corridors remained white to indicate that they were above-water cellars, and I added stairway segments where they connected with the sewers proper. With only a few more water squares, I joined up some otherwise unconnected tunnels and provided links at the borders to the rest of the sewer network. The dark gray gridmarks in the sewer system’s dead ends indicate street access points via drainage gratings. Lastly, I added a couple of new rooms, including a large “sump” room (#7 on the modified map on the right) designed for a dynamic fight scene against Chaos-tainted frog monsters, with a walkway around the edge of the water and a treasure on the stump of a big broken support pillar in the center.
The whole mapping project took less than two hours from start to finish. Another one would go faster now that I’ve gotten a feel for how to go about it. I think, though, that my next map will be completely procedurally generated, as I’m looking forward to being stuck with a premade map and having to find a way to use it as-is. Limitations and restrictions are important for any creative endeavor!