Everyone likes random dungeons! Here’s a simple system for making randomized dungeons that give you some feedback to make them feel like liveable spaces. This is effectively for making dungeons that monsters are currently using as group homes or city-based compounds that the players need to infiltrate.
The first step is to determine how many rooms your dungeon is to have. Is it a relatively simple 6 room complex or a sprawling collection of 20 or more rooms?
Once you get your room number, subtract four and choose the next highest die size (e.g., an 11 room complex gives you a d8). You can vary the size of the die if you want bigger or smaller rooms: the assumption is that smaller dungeons also have smaller rooms and bigger ones have bigger rooms.
Now make a list to fill in of all of your rooms.
If you want more variation, select the first rough 1/3 of your rooms and assign the next smallest die (e.g., a d6 if your main die is a d8) and the last rough 1/3 for the next largest die (e.g., a d10 if your main die is a d8). That way, smaller rooms will tend to be at the front of the dungeon and larger ones toward the rear.
For each room, roll two of whatever die is associated with it and keep the smaller result. Mark that number down in the list. This is the number of 10×10 foot squares the room takes up (i.e., the number times 100 square feet is the space involved). This makes your life very easy if you use Dwarven Forge stuff (which is pretty well locked to a 10 foot grid). If you do your dungeons by hand, you can decide your own meaning for the numbers. The important this is just that larger rooms tend to have more connections and more important stuff in them.
Once you have a size number next to every room, start back at the top. Roll 1d6 and add the result to the room’s size, the compare the total to the following chart to find out what’s in the room:
If you wind up with the same thing a lot, feel free to reroll or pick something adjacent.
Finally, we’ll figure out the connections between rooms.
Get a two dice of your dungeon’s size (e.g., 2d8 if you used d8s for your rooms) that are different colors. Pick one to be positive and one to be negative. Roll both, subtract the negative from the positive, and add the result to the room number. Do this once for each size of the room (e.g., a size 5 room will have 5 connections). You’ll likely get duplicates that will be ignored. You can also safely ignore results equal to the room you’re in and results higher than the last room (unless you’re planning to link the dungeon to a lower level, in which case those rooms have such connections). A result of 0 or less means a connection to the entrance/outside.
Once you have all these connections created, go through and scratch out the unusable ones. Circle mutual connections (e.g., if room 4 noted a connection to 6 and room 6 noted a connection to 4): these will be your major room relationships and you’ll lay out the dungeon to try to get these rooms close together. Also note which rooms have a connection to the entrance, as these will probably cluster toward one side.
Now lay the rooms out in some way that you can start tracing out the connections and then easily move them around to simplify the relationship. Visio or any similar brainstorming/charting software is ideal, Word’s connector and text boxes are only slightly less so (note: you can right click a connector arrow and tell it to “reroute connectors” to get the simplest distance once you’ve moved boxes around), and you can use a big sheet of paper or index cards in a pinch. The major goal is something that will let you move rooms around until the connections are as simple as possible and also to move rooms around based on function.
Once you have a workable layout, draw it up on a grid. All you have to do now is figure out what the layout seems to work best for, stock it with an appropriate threat, and come up with a reason the PCs are invading. The room layout itself should give you a pretty good indication of how the villains in the place are arranged, and what they might be doing when the PCs invade.
For my first dungeon, I decide to make 10 rooms and use a d8 (which is a little high, but not much). I’ll actually roll d6s for the first 3 rooms and d10s for the last 3. My results are:
- 1 – Latrine/Trash – 3
- 4 – Practice/Cells – 4, 3, entrance, 6
- 2 – Bedroom – entrance, 1
- 2 – Bedroom – 5, 6
- 5 – Crafting – entrance, 1, 9, 2,
- 2 – Gathering/Kitchen – 9,
- 3 – Practice/Cells – 6,
over max, 10
- 1 – Guardroom – 9
- 4 – Barracks –
self, over max, 8, over max
- 8 – Warehouse –
self, self, over max, over max, over max, 4, 7, over max
First off, I lay out the rooms with boxes of relatively the right size and make the connections (Image).
Next, I drag the boxes around until they make some kind of sense (Image). I notice that I have a guardroom that connects to nothing but a barracks and a warehouse that’s on the far side of the dungeon without obvious connections to things places that might be stocked by such a room. However, there is a room that has crafting. I start to think that the entrance to the place is actually the PCs entering through a secret door or a window because the two real entrances (the front door through a guard room and a big door into the warehouse) are too secure.
Finally, I lay it all out in a grid and polish out the connections to what makes sense for my master maze tiles and what gives the maximum usable space (Image).
Looking at this, it seems very clearly to be a defended construction location of some kind. Something is made in crafting room 5 and then stored in warehouse room 10 for delivery. The front of the building is the living space for the guards, and the crafters have the bedrooms at the back. The presence of cells indicates either a small contingent of cheap (possibly slave) labor that works for the crafters or, even worse, that sacrifices of some kind are used to create the goods. There are a ton of reasons that PCs might want to invade such a place and stop its production (or just get proof for the authorities).
For my second dungeon, I go with 14 rooms and d10s (d8s for the first 4 and d12s for the last). My results are:
- 1 – Kitchen – entrance
- 7 – Barracks – 3, entrance,
entrance, self, 3, 4, 1
- 2 – Latrine/Trash – 5, 2
- 4 – Office/Private –
self, 5, self, 9
- 4 – Barracks – 2, entrance,
- 5 – Practice/Cells – entrance, 4, 1,
- 7 – Audience Room – 10,
self, 6, 4, 4, 10, entrance
- 2 – Bedroom – 9, 2
- 4 – Latrine/Trash – 6, 1, 5,
- 9 – Chapel – 12, 4, 6, 13,
4, 6, 12, 8, over max
- 4 – Kitchen – 3, 13, 10, 14
- 7 – Office/Private –
over max, over max, 10, 14, over max, self, 13
- 3 – Practice/Cells – 11,
self, over max
- 8 – Assembly – 12,
self, self, 13, 12, over max, 8, over max
Again, I lay it out in relative-sized boxes and plot the connections (Image). This time, I make it a bit easier on myself by making the primary connections big and red and the entrance connections big and green.
I notice that there are a lot of entrance connections, so I try to arrange it so they’re all toward the front: this may be a building with several access points on the facade. I move my primary connections around to preserve the main connections, and wind up dropping several connections that just don’t fit anywhere (Image).
Finally, I go to the grid and wind up making some decisions based on what fits and to streamline the number of access points to the front. If I were running this game for my players, giving them too many ways in would add hours to dithering over how to best assault the dungeon (Image).
The presence of lots of barracks and cells initially suggests a prison of some kind, possibly devoted to a god with the centrally located temple. However, these cells might also be priest cells, and then the map seems to indicate a religious order with a wing of guards that’s attached to the main body but not really part of it. Is this some dangerous cult that’s showing a nice public face while hiding dark secrets? Should the PCs take advantage of being able to bypass the guard wing entirely while risking that they’ll be alerted and attack from behind?