Floor Generation Overview

Floor generation is performed as a list of steps, which allows a developer to customize their floor layout at every part of the pipeline. This page covers the basics of what each step is responsible for and why it is needed.

For information on what steps are required to create a floor from scratch, see Creating Dungeons from Scratch.

Overview

A dungeon map can be generated without items, enemies, or traps. But at a bare minimum, a dungeon map must generate terrain (plus entrance/exit) in order to complete without errors. There are 4 main options on how to do this.

Type	Example	Description	Usage
Grid of Rooms Generation		Rooms generate inside of a grid with cells.	Most dungeon floors
List of Rooms Generation		Rooms generate freely, spreading out from defined halls and rooms.	Uncommon, but used for some dungeon floors
Stairs Floor Generation		Tiles are generated directly on a base of walls.	Rare, primarily debugging
Load Generation	Anything!	Load a pre-made map.	Secret rooms, final floor treasure rooms

To learn more about the technical details of how they generate, visit their pages.

About Steps

Floor generation is broken down into an ordered list of steps, each assigned a priority. The priority determines at what point in the generation process the step should be performed, with a lower number means a step will execute earlier. While these priority numbers do not need to be obeyed for modding, they are the numbers that base PMDO uses.

Priority becomes especially handy when using Zone Steps to plan out dungeon features across multiple floors, rather than a single one.

To view each step that exists and what they do, see Floor Generation Steps.

Priority Brackets

Each range of priority is generally used to perform different tasks. These are each bracket present in PMDO, and what they are generally used for.

Priority	Bracket	Purpose
-6	Floor Data	Setting the initial data of a floor.
-5	Grid Creation	Initializing the grid for GridFloorGen.
-4	Grid Path Generation	Generating rooms and halls for GridFloorGen, as well as editing them.
-3	Room List Creation	Initializing the floorpan for RoomFloorGen.
-2	Room List Generation	Generating the rooms and halls for RoomFloorGen.
-1	Tiles Creation	Placing down the initial tiles of the floor.
0	Tiles Generation	Generating tiles outside of the initial generation.
1	Spawn Tables	Defining spawn tables for the floor.
2	Exits	Placement of entrances and exists.
3	Extra Terrain	The placement of extra terrain types, such as water and tall grass.
4	Textures	Assigns textures to the map. At 4 because textures were formerly placed during this step, but are now placed after all steps are done.
5	Tile Spawns	Spawning tiles, such as traps.
6	Spawns	Spawning other objects, like mobs and items.
7	Debug Checks	Steps that check the dungeon for issues, throwing an error if one is found. Useful for Stress Testing.