The dot patterns are a mnemonic device, as I mentioned. Four spots in a square shape represents a square room. Two spots in a line represents 60 feet of corridor. (I picked "60 feet" because it's the typical radius of most light sources.) Three spots in a line are also a corridor, and five spots are also a room; six spots indicate a rectangular room instead of a square one. These are the foundations of the table I previously presented:
- 1 = 20 foot corridor dead ends
- 2-3 = 60 feet of corridor
- 4-5 = room
- 6 = elongated room
The typical dungeon starts with either stairs down or a tunnel leading into a hill. Roll one die to determine what is at the end of the tunnel or staircase, using the above mnemonic. If you roll a 2 or 3, don't just extend a tunnel in the same direction; the dots on the die line up, so use the orientation of the dots to determine the orientation of the tunnel. Similarly, the walls of rooms don't have to line up on the north-south or east-west axis; if the square symbol on the die is turned 45 degrees compared to the edges of the dice map, make a diamond instead of a square. For a result of 6, a row of three dots indicates the long side of a rectangular room.
For this simple dungeon map, start out assuming each room has one entrance and one exit. If you decide you need more exits, you can go back and place them manually. To determine where the exit is, roll one die on the dice map; the edge it lands closest to indicates which compass direction the exit should be placed. If it lands in the center, the room has a trap door or staircase; roll again for what's on the next floor. The result of the die indicates what the exit leads to: a corridor or room.
For corridors, use the same technique to determine what's at the end of the 60-foot stretch, and in which direction. If the die lands in the center, the passage Ts, or has a doorway on either side. If a passage double backs and crosses an already-mapped portion, insert stairs or a slope. If a passage or room is adjacent to an already-mapped area, feel free to add a secret door if desired.
Spot patterns with a central dot (1, 3, 5) indicate something special. For a 1, roll another die and insert stairs or a trap door if another 1 is rolled. For a 3, roll the die twice when you reach the end of the corridor; this is how you can get Y branches or four- or five-way intersections. For a 5, roll the die twice to determine exits.
I've added a small sample map produced with this method; I've used variations of this technique for about five years to produce rudimentary maps that can be spruced up as much as desired. I started with stairs down, rolled three 4s in a row, then a 5, so I rolled two exits for that room, which turned out to be corridors.
These basic rules will form a foundation for the more elaborate random dungeon procedure.