In chess, Alekhine's Gun is a specific and rarely-seen kind of battery formation in which one player's rook is in front of his other rook, which is in front of his queen. It is difficult to create this formation because it requires several consecutive moves to arrange. However, once created, this form of battery is incredibly deadly and difficult to defend against.
Alekhine's Gun is named, of course, after the great Russian world champion Alexander Alekhine, who famously used the formation to win a decisive victory against legendary Latvian-Danish grandmaster Aron Nimzowitsch in 1930, and again to defeat British Chess Champion William Winter in 1936.