Chess Pins: When a Piece Cannot—or Should Not—Move

A pin ties a front piece to something behind it

A pin occurs along a rook, bishop, or queen’s line of attack. A piece stands between the attacker and a valuable target. Moving the front piece off that line would expose the target behind it.

If that target is the king, the pin is absolute: you cannot make a move that leaves your king in check. If the target is a queen, rook, or another valuable piece, the pin is relative: moving may be legal but costly. This difference tells you whether a move is forbidden by the rules or simply needs careful calculation.

An absolute pin restricts legal moves

White’s rook on e1 points toward Black’s king on e8, with a black knight on e7 between them. The knight is not allowed to jump away because that would uncover a rook check on its own king. It has no move that stays on the e-file.

Do not generalize this to “all pinned pieces are completely frozen.” A rook pinned on a file might move along that file while continuing to block the attack. A pinned piece may also be able to capture the attacker. Judge the resulting position, rather than banning every move made by the piece.

A relative pin can be broken at a price

Move Black’s king to h8 and put Black’s queen on e8 instead. The knight on e7 now shields the queen. Black may legally play ...Nc6 because the king is not exposed. White can then capture the queen with Rxe8+ in this example.

Sometimes moving a relatively pinned piece creates an even stronger threat. It could deliver checkmate, for instance, making the loss of the queen irrelevant. That is why relative pins require calculation instead of a simple legal-move rule.

Pause at any move in a diagram, then open that exact position in Chat to ask about it or in Coach to practice.

Remove the reason the pin matters

Common ways to escape a pin include moving the protected target off the line, blocking the attacker’s line with another piece, or capturing or driving away the attacker. Each option still needs a king-safety check.

In the absolute-pin example, Black can move the king to f8. That changes the knight’s situation: moving it later would no longer uncover a check on e8. The pin has been broken, although Black must still consider White’s next move.

A pinned piece still matters to the enemy king

A pinned knight may have no legal move and still attack squares that the opposing king cannot enter. The rule for king safety counts those attacks. Do not capture a protected piece with your king on the assumption that its pinned defender has stopped defending it.

For practice, compare the two e-file diagrams and name the piece behind the knight before deciding whether ...Nc6 is legal. Identifying that back target is the quickest way to distinguish an absolute pin from a relative one.

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Continue learning

• How Does a Bishop Move? Diagonals, Captures, and Blockers
• How Does a King Move—and When Can It Capture?
• Chess Skewers: Attack the Front Piece, Win the One Behind
• Chess Tactics for Beginners: Spot Forks, Pins and Skewers