Mugen (stylized as M.U.G.E.N) is a freeware 2D fighting game engine designed by Elecbyte. Content is created by the community, and thousands of fighters, both original and from popular fiction, have been created. It is written in C and originally used the Allegro library. The latest versions of the engine use the SDL library. The engine takes its name from the Japanese word 無限 (lit. ’limitless’ or ‘infinity’).
The engine uses four directional keys along with seven buttons for gameplay (A, B, C, X, Y, Z and Start), in order to accommodate six-button fighters which use three punches, three kicks and a start button which is often a taunt. However, characters do not necessarily use all seven buttons, nor need to follow a traditional six or four-button format. At most, two players can control characters, with others being controlled by the engine’s AI (including Watch Mode, a demo mode where the computer controls all characters). AIs can be brutal, strong or even weak. The default AI for the engine however, can walk around and jump, and rarely attacks or guards the player’s attacks when the AI Level is set to Hard. In addition, several gameplay modes are available via the main menu.
