Procedural Content Generation: Runtime Random Level Generation

Runtime Random Level Generation

Runtime Random Level Generation is the generation of game levels while the game is being played, using PCG techniques. When speaking of Procedural Content Generation, most people envisage this type of PCG. It was originated with Rogue which randomly places rooms and corridors when a player first enters the game level.

Runtime Random Level Generation provides an infinite game space, constrained by the generation rules of the algorithm used. It requires that the game store the entire level, which means there must be well defined boundaries between each level. This is usually a set of stairs or elevator. Alternately, there can be no explicit connection between levels, and a level can be left from any point, or when a set of 'victory' conditions is completed. In this instance, levels are accessed from a menu or a central game hub.

All parts of the level must be connected, which increases the complexity of the generation rules. Disconnected parts of the level cannot be visited, unless the game supports removal of existing walls through a grid or voxel based geometry.

Levels are distinguished by being either persistent or non-persistent. With non-persistent levels, each generated level is discarded once the player leaves it. With persistent levels, either a) the each 'floor' of the game is always the same once generated and all exits from the current level lead to one of two adjacent levels, or b) each exit from a level leads to a new level, which results in the game space consisting of a tree of levels branching away from the root which the player first entered where the number of children of the level equals the number of exits from that level, minus the one that the player arrived from.