Mugen

M.U.G.E.N is a freeware 2D fighting game engine created by Elecbyte for building and playing customizable fighting games. The engine provides a modular framework that allows users to import character sprites, sounds, and AI, and combine them with user-created stages and interfaces to assemble new games. Content is created and distributed by the community, enabling crossovers and compilations that mix characters from different franchises.

The system uses data-driven configuration files to describe each character’s moves, hit boxes, and attributes, as well as each stage’s properties such as background layers and music. The engine handles core fighting-game mechanics like inputs, collision, hit detection, health, and game state transitions, while asset creation is handled by the user.

Originating in the late 1990s, M.U.G.E.N was developed by Elecbyte. Active development by the original team largely ceased in the early 2000s, but the project was carried forward by a large community through unofficial builds, forks, and extensive asset libraries. As a result, M.U.G.E.N has become a popular platform for fan-made crossover battles, with thousands of characters and stages available from community sources.

The engine runs primarily on Windows, with community-supported ports and compatibility layers enabling use on other operating systems. It remains widely used in fan modding communities for dream matches, collaborations, and showcasing remixes, though it exists as an unofficial ecosystem rather than a commercial product.