游戏模块，英文多简称为「MOD」、「Mod」（全称「Modification」），「修改」的名词含义。MOD通常对应可以修改的电子游戏，因此以电脑游戏为主。必须依赖与原作品方可运行游玩。游戏中的道具、武器、角色、敌人、事物、模式、故事情节等任意部分都可能属于修改范畴，多见于著名电子游戏作品，游戏类型多数为第一人称射击游戏、即时战略游戏、角色扮演游戏（非日式）、动作游戏，著名实例包括红色警戒2、毁灭战士系列、横扫千军、雷神之锤系列、战栗时空系列、当个创世神、魔域幻境系列、无冬之夜系列、地牢围攻系列、上古卷轴5和侠盗猎车手系列等。

A mod or modification is the alteration of content from a video game in order to make it operate in a manner different from its original version. Mods can be created for any genre of game but are especially popular in first-person shooters, role-playing games and real-time strategy games. Mods are made by the general public or a developer and can be entirely new games in themselves, but mods are not stand-alone software and require the user to have the original release in order to run. They can include new items, modded weapons, characters, enemies, models, textures, levels, story lines, music, money, armor, life and game modes. They can be single-player or multiplayer. Mods that add new content to the underlying game are often called partial conversions, while mods that create an entirely new game are called total conversions and mods that fix bugs only are called unofficial patches.