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). However, characters do not necessarily use all seven buttons, nor need to follow a traditional six or four-button format. 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. The lifebar used originates from Capcom vs. Gameplay Original character Dragon Claw fighting Darkstalkers character Hsien-Ko in the RAW is WAR ring. The latest versions of the engine use the SDL library. It is written in C and originally used the Allegro library. Content is created by the community, and thousands of fighters, both original and from popular fiction, have been created. Mugen (stylized as M.U.G.E.N) is a freeware 2D fighting game engine designed by Elecbyte.
