Attack

An attack describes the squares on which a piece has capturing power. An opposing piece on one of those squares is attacked even when no capture is made on the current turn. The attack depends on the piece's movement pattern and on any pieces blocking its path.

Under the formal rules, a piece can attack a square even when it is pinned, meaning that moving it would expose its own king and make the move illegal. This distinction matters because a king may not enter an attacked square and because castling, the combined king-and-rook move, may not cross an attacked square.

Pinned piece that still attacks

A pinned piece keeps its attacks

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The rook on e1 pins the knight on e7 to the king on e8.

Attack under an absolute pin

The white rook on e1 absolutely pins the black knight on e7 to the king on e8. The knight has no legal move, but its movement pattern still attacks f5.

1. The rook on e1 pins the knight on e7 to the king on e8.
2. Although pinned, the knight still attacks f5.

Pawns show the difference between movement and attack especially clearly: they advance straight forward but attack one square diagonally forward. Rooks, bishops, and queens attack along lines but cannot pass through intervening pieces. Many tactics, such as a fork, one move that attacks two or more targets, are built from this geometry.

Pawn advance and attackStopped line attack

A pawn moves straight and attacks diagonally

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The pawn on d4 attacks c5 and e5.

Moving is not attacking

The white pawn on d4 can advance to d5, but it attacks c5 and e5. The d5 square is not part of its capture pattern.

1. The pawn on d4 attacks c5 and e5.
2. d5 is an advance square, not a square attacked by the pawn.