In chess, a skewer is an attack upon two pieces in a line. It is similar to a pin, with the difference being that in a skewer, the more valuable piece is usually the one under direct attack, while the less valuable piece is behind it.[1] The opponent is compelled to move the more valuable piece to avoid its capture, thereby exposing the less valuable piece which can then be captured (see chess piece relative value).[2] Only line pieces (i.e. bishops, rooks, and queens) can skewer; kings, knights, and pawns cannot.