Editing Rules of chess (section)

===Check===
{{Main|Check (chess)}}
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 |Black's king is in check. It can get out of check by moving to an unattacked square. Black can also parry the check by moving the bishop to e5 or the knight to f4 to block the check, or by capturing the white bishop with the knight.<ref>{{Harvcol|Harkness|1967}}</ref>
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A king is ''in check'' when it is under attack by at least one enemy piece. A piece unable to move because it would place its own king in check (it is [[pin (chess)|pinned]] against its own king) may still deliver check to the opposing player.{{sfn|FIDE|2023|loc=article 3.9}}

It is illegal to make a move that places or leaves one's king in check. The possible ways to get out of check are:
* {{em|Move}} the king to a square where it is not in check.
* {{em|Capture}} the checking piece.
* {{em|Interpose}} a piece between the king and the opponent's threatening piece ({{em|block}} the check).{{sfn|Just|2019|loc=chapter 1, section 12A}}<ref>{{Harvcol|Polgar|Truong|2005|pp=32,103}}</ref><ref>{{Harvcol|Burgess|2009|p=550}}</ref>

In informal games, it is customary to announce "check" when making a move that puts the opponent's king in check. In formal competitions, however, check is rarely announced.{{sfn|Just|2019|loc=chapter 1, section 12F}}