In gaming, "map mods" are custom files created by players or developers to expand or alter the playable area of a game. These are commonly found in simulation, survival, and RPG titles.

Creating a map mod is one of the most grueling tasks in game development. It involves "level design"—manipulating meshes, texturing landscapes, placing trees and rocks by hand, and ensuring the game engine doesn't crash when two roads meet at a weird angle.