Gundam War: Mobile Suit Gundam the Card Game, known more informally as Gundam War or GW, is a collectible card game based on the Gundam anime franchise published by Bandai. It was first released in Japan in February of 1999, and would get twenty-eight expansions over the years until the cessation of printing in 2011. The gameplay of Gundam War would inspire the Crusade system of card games for other franchises outside of Gundam, debuting in October, 2007 with Sunrise Crusade. A direct successor card game, Gundam War Nex-A, would be released in the fall of 2011, and some Gundam War cards would still remain playable in Nex-A. Gundam War thus became known as "old GW" among collectors.
Players can collect cards and form decks, which are divided into colors depending on faction. Using their deck they could battle other players. The game is officially designed for two players, though fan-created rules for more players exist. A Chinese version and an English version of Gundam War were both launched in 2005, however the English version was short-lived and only received three updates before being discontinued. This English edition is sometimes confused with the similar, and similarly named, Gundam M.S. War Trading Card Game, which was released in the United States in 2001.