Forced move

A forced move is a reply whose choice is extremely restricted. In the strictest sense, it is the only legal move. For example, a player in check may have only one legal way to keep the king safe.

Only legal reply

Only one legal reply

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The black rook on h8 checks the white king along the h-file.

The restriction comes from the rules

White is in check. The board leaves Kg1 as the only legal move. The black rook creates the restriction, and the position shows the available reply, not a visible thought process.

1. The black rook on h8 checks the white king along the h-file.

In practical usage, a move is also called forced when other legal choices exist but all allow mate, a decisive loss in piece and pawn value, or some other immediate and clearly unacceptable result. This second meaning depends on analysis: if an alternative thought to lose is actually viable, the move was not truly forced.

Practically forced reply

Three legal moves, one avoids mate

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The restriction comes from the consequences

White can play h3, h4, or hxg3. Both h3 and h4 allow the immediate reply Qh2#, while hxg3 removes the queen. The board shows the options and their consequences; it does not display an internal choice process.

One forced reply may begin a forced sequence and lead to a forced win or forced draw. It should not be confused with a forcing move. A forcing move creates a threat and restricts the opponent’s replies; a forced move is the restricted reply the opponent must find.