In chess and similar games, check is a condition that occurs when a player's king is under threat of capture on the opponent's next turn.
A check is the result of a move that places the opposing king under an immediate threat of capture by one (or occasionally two) of the player's pieces.
Under the standard rules of chess, a player may not make any move that places or leaves their king in check.
In fast chess, depending on the rules in effect, placing or leaving one's king in check may result in immediate loss of the game.
In this usage, the words "check" and "chess" come via Arabic from Persian shāh, meaning "king"[7] or "monarch" (Murray 2012:159).
Less commonly (and obsolete), the warning garde can be said when a player directly attacks the opponent's queen in a similar way.
In the FIDE rules for rapid chess, if a player leaves or places their king in check or commits any other illegal move, their opponent can claim a win.
Some attacks involve numerous checks to force an opponent into a losing position, especially when the king is exposed.