Vanilla Doom does not support replacing sprites from inside PWAD files older graphical mods would commonly be distributed with a small tool named DeuSF that would work around this limitation (modern source ports have entirely removed the restriction).Ī WAD file always starts with a 12-byte header. WAD files contain certain limitations: for example, much of the game behavior cannot be changed without patching DOOM.EXE using a tool such as DeHackEd (modern source ports allow DeHackEd patch files to be included in WAD files). This is in comparison to Wolfenstein mods, where the main game resource files had to be modified in order to make any change. Mods containing new levels, graphics, sound effects and music are natively supported by vanilla Doom without needing any special third party tooling they can simply be loaded using the -file command line argument. The WAD file system is the primary mechanism that allows easy modding by fans. Rather than causing id Software to seek to suppress such mods, they encouraged the developers to make Doom more easily moddable. After the release of Wolfenstein 3D in 1992, fans developed unauthorized mods of the game that changed elements such as levels and monster graphics.
