M.U.G.E.N. is a customizable 2D fighting game engine that allows users to create and incorporate their own characters, stages, and other content. Obtaining these games for personal computers typically involves acquiring the engine itself and then downloading character packs, stage files, and screenpacks created by other users. These elements are then integrated into the engine to build a custom fighting game experience. A collection of these game files is then commonly referred to using the relevant search terms.
The appeal stems from its open-source nature and the ability to create essentially any fighting game scenario imaginable. Users are not limited by pre-defined rosters or game mechanics, fostering a community that values creativity and customization. This approach offers a deep level of personalization not usually found in commercial fighting games. Historically, the availability of these customized experiences has relied on online communities, forums, and file-sharing sites.