Metal Gear (Japanese: メタルギア Hepburn: Metaru Gia) is the name for a series of mecha in the Metal Gear series. In the series, a Metal Gear is defined as a bipedal nuclear weapons-equipped tank. Usually each game has a new Metal Gear with a different role. The Metal Gears are typically autonomous nuclear launch platforms which the player must destroy in order to save the world and complete the game. Often confronting the latest Metal Gear model is one of the final challenges of each game.