Reference

Glossary

Terms as introduced in lessons, in the order they first appear. Grows over sessions — this is the vocabulary every lesson should stay consistent with.

Procedural generation (procgen)

Creating content — levels, items, characters — algorithmically at runtime or build time, rather than hand-authoring every instance. In a dungeon crawler: the dungeon layout is computed by a function, not drawn by a level designer.

PRNG (pseudorandom number generator)

An algorithm that produces a sequence of numbers that looks random but is fully determined by its starting state (the seed). Godot's RandomNumberGenerator class is a PRNG.

Seed

The starting value fed to a PRNG. The same seed always produces the same sequence of "random" numbers — this is what makes a generated dungeon reproducible: save the seed, regenerate the exact same layout later.

Deterministic

Same input, same output, every time. A procgen algorithm is deterministic if, given the same seed and parameters, it always produces the same result. Determinism is what makes bugs reproducible and lets players share seeds.

Rejection sampling

A generate-and-test strategy: propose a random candidate (e.g. a room rectangle), check if it satisfies a constraint (e.g. doesn't overlap existing rooms), keep it if valid, discard and retry if not. Simple to implement, can be slow if valid candidates are rare.

Grid

A 2D array representation of dungeon space, indexed by [x][y] (or a flat array with computed index). Each cell holds a tile type (wall, floor, door, etc.). The substrate most dungeon algorithms write into.

Region

A connected group of tiles treated as a single unit for connection purposes — a room is a region, a maze corridor segment is a region. Dungeon-connection algorithms (see Nystrom, "Rooms and Mazes") build a graph where regions are vertices.

Corridor / tunnel

A carved path of floor tiles connecting two rooms so a player can walk between them. Rooms placed by rejection sampling (Lesson 1) are disconnected "islands" until corridors link them.

L-shaped tunnel

The simplest corridor shape: one horizontal segment plus one vertical segment, joined at a corner, connecting two points that don't share a row or column. Which segment comes first is a coin flip — it changes the corridor's shape, not whether it connects the two points.

Connectivity / traversable

A dungeon is connected (traversable) if every room is reachable from every other room by walking through corridors. It's a property of the graph formed by rooms (vertices) and corridors (edges), not of any individual room or corridor.

Chain connection

Connecting room i to room i-1 for every room in sequence. Guarantees full connectivity with the fewest possible corridors (a spanning tree shaped like a straight line) — simple, but produces long corridors and no loops. See Lesson 2.