CON mutator

Introduced in EDuke32 are the concept of CON modules, which can be used with the -mx command line parameter. These are standalone CON files that make adjustments and additions to the code and can work in tandem with other modules.

CON mutators are a specific kind of CON module that meets certain guidelines in order to be interoperable and compatible with base CON files and other mutators. Mutators can be used to alter game functionality in certain ways or provide "libraries" of sorts containing additional code assets for mappers, to name a few example uses.

Replacing Actor Code

Each time an actor or useractor block is created, its contents completely overwrite any others for the same tilenum above its position in CON compilation order. This is useful if you want to completely change an existing actor, and may be necessary for some changes albeit having to duplicate the code.

Supplementing Actor Code and Event Code

Unlike actors, events work in an additive fashion. All instances of EVENT blocks are compiled and used by the game. This allows for true "mutators". EVENT_GAME allows coders to modify actor code without completely replacing it as actor blocks do.