check

In games such as chess, shogi, and xiangqi, a check is the threat to capture the king (or general in xiangqi) on the next turn to move. A king so threatened is said to be in check. In the following move, the player whose king is in check must get their king out of check, if it is possible. Either the threat must be stopped (by interposing a piece between the threatening piece and the king, or capturing the threatening piece) or the king must be moved to a space where it is no longer in check. If the player cannot get out of check, the game ends in checkmate and the player loses. Announcing “check” is optional.
A check is the result of a move that places the opposing king under an immediate threat by one (or sometimes two) of his pieces. (In some chess variants, check by more than two pieces is possible.) If the king is in check and there is no legal move which gets the king out of check, the king is said to be checkmated and the game is over. The player whose king is checkmated loses…