Multi Theft Auto (MTA) is a modification for the PC versions of Grand Theft Auto III, Grand Theft Auto: Vice City and Grand Theft Auto: San Andreas that allows them to be played online against other players around the world, in a manner similar to Grand Theft Auto Online. Although often referred to as a mod, MTA is mostly based on the trainer and code injection methods of manipulating the game through its own memory and does not alter any original files supplied with the game itself.