Forcing move

A forcing move makes the opponent address an immediate consequence and therefore restricts the available replies. A check is the clearest case: the next move must end the attack on the king. A capture or concrete threat can also be forcing when ignoring it would cause a serious loss.

Capture or threat that narrows options

A material threat that demands attention

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The knight on d5 currently attacks the queen on c7.

The queen is attacked

The knight on d5 attacks the queen on c7. Qd6 is a legal reply that removes the queen from attack. The threat narrows the set of reasonable replies without being a check.

1. The knight on d5 currently attacks the queen on c7.
2. Qd6 is a legal queen retreat in response to that threat.

Forcing does not mean that only one reply exists. A check may allow several defenses, and a capture may be ignored if the opponent has a stronger counterattack. The point is that the set of reasonable replies becomes small, making calculation of variations, imagined move sequences, easier and more reliable.

Check with several defenses

A check that restricts without forcing one reply

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Kd7, Kd8, Ke7, and Kf8 are the four legal escapes.

Four legal evasions

The black king is in check. It has four legal escapes: Kd7, Kd8, Ke7, and Kf8. The board shows an objective restriction, not a mental process or a unique reply.

1. Kd7, Kd8, Ke7, and Kf8 are the four legal escapes.

These moves are often examined early when forming candidate moves, especially through the checks, captures, threats scan. A forcing move is not necessarily good, however. It may lead to an inferior position, lose material, meaning pieces or pawns, or drive the opponent toward a favorable defense.

Forcing but inferior

A forcing capture that worsens the position

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The black king on b7 can capture the white rook on a6.

The recapture determines the consequence

The black king on b7 can play Kxa6. The recapture removes the white rook and leaves Black with a decisive advantage. The board shows that material consequence, not an internal decision.

1. The black king on b7 can capture the white rook on a6.

Accurate analysis also searches for the opponent's forcing replies, such as a check against your king or a capture inserted before answering the original threat.