RDG: Filling in Corridors

Another post on the topic of Random Dungeon Generators… Previously, I mused about generating megadungeons zone by zone, starting with zone themes I previously described, with a central feature acting like a hub, and filling in the area around the hub with more generic rooms and passages, stocked randomly. One problem you encounter with a lot of random dungeon generators is that they tend to be very slow, filling only a small area at a time. This may seem to be irrelevant when using an RDG for prep instead of generating as you play, solitaire or otherwise; however, when you need to fill large areas, such as in a megadungeon, it’s very tedious. It makes more sense to generate multiple passageways first, then generate the rooms or other features you discover as you explore the passageways.

Imagine a tic tac toe board. One of the squares, selected randomly, is the location of a special feature in a zone (evil shrine, drawbridge, prisoner pit, king’s throne room, etc.) If using an RDG for random prep, number the squares clockwise from the top center and roll a d10 to place the special feature (9 or 0 both indicate the center square.) If you are generating a dungeon during play, roll a d10 as you enter each region; on a 1-2, it’s the special feature. All the other squares are random passageways. what kind depends on the zone structure type:

• Caverns: irregular tunnels that snake and fork, occasionally widening into caves
• Warrens/Maze: lots of twisty, narrow tunnels, with only the occasional room or wider area
• Tombs: maze with sporadic clusters of rooms
• Ruins: more frequent room clusters
• Fortified Area: mostly adjacent rooms connected by short passageways

I’ll leave Caverns and Forts for later, but Mazes, Tombs and Ruins share some features and can be dealt with as a group. You need a lot of standard corridors sprawling through the area, sort of like streets in a city, which suggests that you could use leximorphs – words with the letters written close together – to define the tunnels. We can use the method Zak describes for neighborhood street maps in Vornheim: roll a d20 and spell out the numeral rolled.

However, to keep the patterns from becoming too stale, roll a d6 with pips at the same time as the d20. This represents (a) how many letters of the number’s name to use; and (b) the arrangement of the letters. Thus, one dot means only use the first letter; two or three dots means the first 2-3 letters, arranged horizontally, vertically or diagonally as indicated by the orientation of the dots on the d6; four or five dots means arrange the letters clockwise around a square or diamond, starting at the top and ending in the center (for a Five;) and six dots is a clockwise rectangle of six letters. The strokes of the letters are five-foot or ten-foot-wide corridors.

For mazes, each end-point that doesn’t touch another corridor potentially ends in a room. For tombs, they potentially end in room clusters (d6 with pips, dots represent location of rooms.) For ruins, each end-point and each juncture of two or more strokes potentially has a room cluster. Roll on the following table:

1. Archway(s) with Room(s) beyond
2. Door(s) with Room(s) behind
3. Arrow Trap (at juncture only), otherwise passage continues to next area
4. Falling Rubble, passage continues to next area
5. Pool of Liquid
6. Spike Trap (at juncture only), otherwise passage continues to next area
7. Pit Trap, passage continues to next area
8. Dead End

Roll a d8 for Ruins, d12 for Tombs, and d20 for Mazes and Warrens; any result over 8 means a Dead End in a Tomb or a passage that continues in a Maze. If the Maze is a lair for wild beasts, Door results will be archways or openings.
I’ll cover adding rooms in the next installment.

Written with StackEdit.