Check
Check is the state of a king that stands attacked by one or more opposing pieces; the player whose king it is must end the attack with the very next move, because no legal move may leave one's own king attacked.
Two rules from the Laws of Chess define it. A king counts as in check even when the attacking piece is itself pinned and could not legally move, and no move may leave or expose your own king to attack. A pinned piece of yours therefore often cannot help.
When you are checked, run through three questions. Can the king step to a square no enemy piece covers? Can the checking piece be taken, by the king only if it is undefended, or by any other piece? Can a piece be placed on a square between the checker and the king? The last option exists only against a queen, rook or bishop at a distance. Checks from a knight, a pawn or an adjacent piece cannot be blocked, and a double check can be met only by moving the king.
Checks are the most forcing moves in chess, so look at every one of them first when you calculate. A sequence of checks can win material, chase a king into a mating net or force a draw by perpetual check. Do not give checks without a purpose, though, since a pointless check can drive the king to a better square.
Defensive habit: before each move, list the checks your opponent will have afterward.
A frequent slip is trying to capture a defended checking piece with the king, which is illegal.
A neighboring idea is Absolute pin. An absolute pin is a pin in which the piece behind the pinned piece is the king, so the pinned piece cannot legally move off the line at all.
It sits close to Touch-move rule. Touch-move is the over-the-board rule that binds a player to a piece once it has been deliberately touched: your own piece has to be moved and an opponent's piece has to be captured, wherever a legal move exists.
A neighboring idea is Discovered check. A discovered check is a check from a piece that did not move: a bishop, rook or queen is unmasked when the piece in front of it leaves the line to the king.
Once "Check" is familiar, the next question is what to work on at your rating, which the improvement plans by rating band answer with game and puzzle data.
Related terms
Checkmate, or mate, ends a chess game at once: the king of the side to move is under attack, and none of that side's legal moves can remove the attack, so the player who delivered it wins.
A double check is a single move that puts the enemy king under attack from two pieces simultaneously, typically one that moved and one it unmasked, so only a king move can answer it.
A discovered check is a check from a piece that did not move: a bishop, rook or queen is unmasked when the piece in front of it leaves the line to the king.
A perpetual check is a run of checks that the defending king cannot sidestep, so the same positions recur and the game is drawn by repetition, rescuing the side that was losing.
An absolute pin is a pin in which the piece behind the pinned piece is the king, so the pinned piece cannot legally move off the line at all.
King safety is the degree to which a king is protected from attack, as determined by its pawn cover, the defenders nearby, the open lines pointing at it and how quickly the opponent can bring attackers to the area.
Guides that go further
What to decide first, the questions to ask, what a first lesson should show and the red flags to avoid.
How much does chess coaching cost?
Published rates for private, group and subscription chess coaching, with the source and the date of each.
A game review, a read on your level and a written study plan from George Li.
Sources
- FIDE Laws of Chess (taking effect from 1 January 2023), Article 3.9.1, read Oct 21, 2026.
- FIDE Laws of Chess (taking effect from 1 January 2023), Article 3.9.2, read Oct 21, 2026.
Want to spot this in your own games?
A first lesson starts with your games: George reviews them and builds a study plan around what he finds.