MechWarrior 4: Vengeance is a computer game eveloped by FASA Interactive and published by Microsoft. Released on November 24, 2000, this game is the fourth in the MechWarrior series. It takes place in the BattleTech universe where the pinnacle of all war machines are huge, heavily armed robots called Battlemechs. The player pilots one of these 'Mechs and uses a variety of weapons (autocannons, lasers, missiles, ...) to battle enemy 'Mechs, tanks, and other vehicles. An expansion pack, MechWarrior 4: Black Knight, was released in October 31, 2001, and a subsequent stand-alone expansion, MechWarrior 4: Mercenaries was released in November 7, 2002.