Gameplay mod

A gameplay mod is a fan-made modification of some portion of gameplay. Many of these have been created for classic Doom, changing the weapons or monsters or specific gameplay mechanics. Some of them add entirely new functionality, such as a flashlight or footstep sounds. Thus players of mod-friendly source ports, like GZDoom, often use multiple gameplay mods together.

Gameplay mods for classic Doom are intended to be used with regular maps, including the vast majority of fan-made maps. Notable examples are Brutal Doom and Corruption Cards.