MMO-A massively multiplayer online game (also called MMO and MMOG) is a multiplayer video game which is capable of supporting large numbers of players simultaneously. By necessity, they are played on the Internet. ok you got me on that one, but let me just say. tower 12 people only. RPG-A role-playing game (RPG) is a game in which each participant assumes the role of a character, generally in a fantasy or science fiction setting, that can interact within the game's imaginary world. ok you got me on that one as well, but this is very very limited interaction with the game's imaginary world.