Chess with different armies

Chess with Different Armies, also called Betza's Chess or Equal Armies, is a chess variant invented in 1979 by Ralph Betza. Instead of both sides using the standard FIDE chess set, each player selects one of several purpose-built armies of fairy chess pieces, designed so the armies are roughly equal in overall strength even though their pieces move in different ways. The kings and pawns stay the same across every army, so the familiar checkmate and pawn-promotion goals of chess are unchanged, but the non-royal pieces differ sharply from one army to the next. Betza originally proposed four armies for the variant: the standard FIDE pieces, the Colorbound Clobberers, the Nutty Knights and the Remarkable Rookies, each built around a different balance of short-range and long-range movement. Because the armies are not mirror images of each other, players must learn distinct piece values and tactical patterns for each side, which has made the variant a recurring subject of study among fairy-chess enthusiasts and a fixture of chess-variant tournaments and online play. It is played by two players on a standard eight-by-eight board.