4 player chess. 2 peasant players (white and black) and 2 noble players (white and black). Movement patterns remain untouched, but the game ends at king capture, rather than checkmate. In a typical chess game, this would occur 1 move after checkmate (it's implied, but too barbaric to actually go through with in a normal game), but in this variant, incentives are mixed and the kings don't always get their way. Moving into check (via castling also, but not through it) is allowed.
Each peasant player controls pawns of their color. Each noble player controls the king and queen of their color. Pieces, aka "military" are potentially controlled by nobles or peasants.