Trapped piece

A trapped piece has no safe square or practical route of escape. Its movement may be restricted by friendly pieces, the edge of the board, or squares controlled by the opponent. Queens, rooks, bishops, and knights can all be trapped. Even when capture is not immediate, the piece may be unable to take a useful part in the game.

The tactical motif often develops in two stages. First, the escape squares are reduced or controlled. Then the piece is attacked with tempo, meaning the attacker improves the position while forcing a response. The victim may sometimes open an exit through a sacrifice, exchange itself for another piece, or create a more urgent threat.

To prove that a piece is truly trapped, check every legal move and every intermediate move that creates a threat before attempting the retreat. A piece that looks enclosed may escape by giving check, capturing a defender, or exploiting counterplay, active play that creates a more urgent problem for the opponent.