Mo or modification is a term generally applied to computer games, especially first-person shooters, RPGs and real-time strategy games. Mods are made by the general public or a developer, and can be entirely new games in themselves. They can include new items, weapons, characters, enemies, models, textures, levels, story lines, music, and game modes. They also usually take place in unique locations. 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.