PERM

PERM is a CAOS function which defines how an agent interacts with the doors within a world.

Doors have their own permeability function which ranges from 0 to 100, with 0 meaning that nothing can pass through the door and 100 meaning that anything may pass through the door.

The PERM function defines the limit at which an object recognizes a door as impassible. For instance, if an object's PERM is 100 it will pass through any door which has a permeability greater than 0, and an object with a PERM of 0 will not pass through any door with a permeability less than 100.

Whenever PERM changes, the engine checks that the agent is in a valid position in the world. It replaces the SIZE command in Creatures 2.