When playing a tabletop roleplaying game, a Game Master on a tight budget may find themselves in a bind for ways to build engaging dungeon maps. The following system can be used with a 6-sided dice, an 8-sided die, or a 20-sided die, combined with an ordinary pack of playing cards (which the user may draw dungeon chambers on, to their specifications, or leave unmodified, instead consulting a dice table such as those here shown).
The obvious drawback of this system is simply that it does none of the heavy lifting of storytelling for you, in regard to what specific loot, traps, enemies, allies, or objectives are found in the dungeon. This system is intended for GMs who have an arsenal of ideas (or game materials which cover the same bases), and who just want to introduce a moderate level of randomness or organic modularity into a process which is otherwise fairly repetitive and predictable, akin to procedural map generation in a roguelike game.
In this system, four chambers of a dungeon are generated at one time, with their placement relative to each other based on the shape of one of the Tetromino pieces in the game Tetris. Here I will be using the classic Tetris nomenclature to refer to each Tetromino according to their approximate shapes: I, O, T, J, L, Z, and S.
The I or "line piece" may be oriented north-south, east-west, or vertically stacked over one another, and in a dungeon map it represents a series of four successive chambers or/and corridors which are passed through in a straight line, with no side exits. It can be a tower of four consecutive levels, or a pit likewise of four levels descending belowground.
The O or "square piece" is four chambers which join each other in a square configuration. This can be a two-storey building with two rooms on each storey (a vertical orientation), or it can be all on a single horizontal level.
The T piece is shaped just as its name suggests, with a set of three consecutive chambers, and a right- or left-hand turn off the middle of the three (or, in a vertical orientation, an ascending or descending set of stairs off the middle chamber).
The J and L pieces are sets of three consecutive chambers, with a turn off the farthest-away chamber, to whichever direction you prefer: right, left, up, or down. Only the left or right orientation differs between J and L, the "handedness" of the turn.
Finally, the Z and S pieces are "zigzags" consisting of two chambers, a right angle turn, and then two more chambers proceeding in the same direction as the original. As with J and L, only their orientation of "handedness" to the left or right determines whether a piece is a Z or an S.
Using a d6
- I
- O
- T
- J or L (you select the orientation)
- S or Z (you select the orientation)
- The chamber the party is currently in has a secret passage which loops back to a previously-visited chamber, or else deposits them at the exit of the dungeon, according to your preference and goals for the mission.
Using a d8
- I
- O
- T
- J
- L
- Z
- S
- As in the d6 table above: the dungeon loops back or deposits the party at an exit.
Using a d20
- I oriented on the X axis (east / west)
- I oriented on the Y axis (up / down)
- I oriented on the Z axis (north / south)
- O oriented horizontally (X and Z axes)
- O oriented vertically (Y axis with either X or Z axis)
- T branching to the north
- T branching to the east
- T branching to the south
- T branching to the west
- T branching upward
- T branching downward
- J or L resulting in a turn to the north
- J or L turning east
- J or L turning south
- J or L turning west
- J or L turning upward
- J or L turning downward
- S or Z running in an east / west orientation
- S or Z running in an up / down orientation
- S or Z running in a north / south orientation
How to use the deck of 52 or 54 playing cards
- Draw 4 cards, each of which corresponds to one chamber of the dungeon. You may order them however you please, and you may repeat rolling the die and drawing more cards, if it pleases you to make the dungeon last longer. Bear in mind that the party may not avail themselves at all of branching paths, such as in a T configuration, so not all rooms might get used, or might be visited in a sequence you did not originally intend. It is up to you as the GM to decide if you would rather the dungeon's layout be definitive and "locked in," or if you simply prefer to present the party with dungeon features in a specific order, railroading their dungeon experience no matter which ways they turn.
- Hearts are chambers containing something beneficial to character health or the development of their personalities, such as a health potion, food, or a clue or document that can advance the personal plot arc of a party member.
- Diamonds are chambers containing something that looks attractive to loot, whether or not it is actually beneficial, such as armour, weapons, magical scrolls, or treasure. It's up to you if you'd like it to be booby-trapped.
- Clubs are chambers containing enemies and threats which are obviously recognisable as threats.
- Spades are chambers containing threats which must be proactively searched for, if they are to be detected before they put the party in danger, such as a dungeon trap, flooding in an underground chamber, toxic underground gases, or cave-ins.
- Face cards are significant characters: a boss enemy, a trapped ally, a stranger in need of rescue, a mythic king who has been asleep buried under a hill for centuries, etc. The value of the face card corresponds to that character's overall power within the plot: Kings are powerful characters whose capabilities exceed the party's collective ability; Knights are characters who cannot act without assistance (or will not attack unless provoked or a conversational skill check is failed, in the case of enemies); Queens fall between these extremes, with power or capabilities about on par with that of party members.
- Jokers, if you choose to include them, are comic relief characters who are secretly the key to a puzzle later in the dungeon (the red Joker) or secretly a dreadful fiend in disguise, waiting to betray the party (the black Joker).
- Pip cards have a "value" or "severity" corresponding to the number of pips. A 10 of Hearts has the greatest possible benefit to the party of every chamber in the entire dungeon, while a 2 of Spades contains a trivially navigable and easy-to-detect trap. Aces are rooms where the unique feature is very well hidden but extraordinary, e.g. a weapon of mass destruction disguised as a harmless bird figurine, or a magic bean that can grow into a beanstalk high enough to stage an assault on the realm of the cloud giants. In any case, an Ace seems uninteresting and innocuous, but it is always something significant enough to be worth searching for.
If you enjoy the affordability and portability of using minimal RNG tools to create dungeon layouts, you may also enjoy this similar system by Shieldice Studio, an independent developer of system-agnostic tabletop gaming materials for dungeon generation and worldbuilding. The Shieldice system uses a d6 and a d12 in tandem to determine room positions on a 2-dimensional grid, then the possible contents of those rooms.
Iron Noder 2023, 20/30