Partial conversion

A partial conversion is a PWAD that signficantly alters the original game, intending to provide a distinctly different experience. However, in contrast to a total conversion, the partial retains enough visuals, sounds, and gameplay mechanics to be considered a variant of the original, not a separate game. The term was first used by the STRAIN project, which had a smaller scope of changes to Doom than Aliens TC or other prior total conversions.

One important factor distinguishes a partial conversion from a gameplay mod: custom maps. Partial conversions are self-contained experiences with custom maps and gameplay changes. But gameplay mods do not have maps and are thus intended to be used with any number of regular maps.

To complicate matters, the community has a history of using the term loosely. For example, Back to Saturn X billed itself as a partial conversion, but it is actually just maps with custom textures and no gameplay changes. Since maps with custom textures have become quite common, this is no longer generally accepted as a partial conversion.