DUMMY is a stage in Super Smash Bros. Melee which can only be found via Action Replay. When activated in Debug Mode, it normally crashes the game, though another hack can force the game to present the stage. It merely consists of empty space, save for a lone invisible platform in the center that can only be seen using the debug menu.
The purpose for DUMMY remains unknown to this day; while other stages, such as TEST and IceTop have been speculated to be programming tests, DUMMY has nothing to show what it was used for. It has been speculated, however, that the stage is used for the victory screens, the background of the debug menu, the start of the E3 trailer of Brawl, among other theories.