Extinction Chess

Extinction chess is a chess variant invented by R. Wayne Schmittberger, editor of Games magazine, in 1985. Instead of checkmate as the winning condition, the object of the game is the elimination of all of a particular kind of piece of the opponent. In other words, the objective is any of the following:

• capture the opponent's king;
• capture the opponent's queen;
• capture both of the opponent's rooks;
• capture both of the opponent's bishops;
• capture both of the opponent's knights;
• eliminate all of the opponent's pawns, including by promotion.

Since the king is not a special piece in this game, it is legal to castle when in check, or to castle through check. Promotion to king is also allowed. (Although losing the king loses the game, it can legally be captured. If there are two kings of the same color, e.g. after a promotion to king, either may be captured without the loss of the game.)