A discovered attack hides in plain sight. One of your pieces stands on a line, and another of your pieces stands in front of it. You move the front piece, and the piece behind suddenly attacks whatever is on that line. If the target is the king, you have a discovered check. The front piece is free to capture, fork, or simply land on a square that would otherwise be illegal, because the opponent must answer the check.

The shape

Bishops and rooks are the pieces that wait behind. Knights are the pieces that usually step off the line, because a knight move leaves every rank, file, and diagonal. A White bishop on b2, a White knight on d4, and a Black king on g7 is the textbook picture. The knight blocks the long diagonal. The moment the knight moves, the bishop checks the king.

The knight's landing square is the whole point. It can capture a queen on c6, or fork a rook, or take a pawn, and Black does not get to recapture until the check is answered. You are making two attacks on one turn. Only one of them can be met.

💡 Chess Hint: Find your bishops and rooks first. Then ask which of your own pieces is standing in their way. That piece is a candidate for a discovered attack.

Double check

Sometimes the piece that steps off the line gives check itself, and the piece behind gives check as well. That is a double check. It cannot be blocked and it cannot be answered by a capture of just one checker. The king must move.

Double check is the engine of several classic mates. In the smothered-mate pattern, a knight on f7 moves to h6 and discovers check from a queen sitting on the a2–g8 diagonal, while the knight checks too. The king is dragged to h8, the queen sacrifices on g8, and the knight returns to f7 for mate once the king is boxed in by its own rook and pawns. The full picture is in checkmate patterns.

Discovered attacks that are not checks

The same geometry wins material without checking. A rook on the c-file, your knight standing on c4, and an undefended enemy rook on c8: move the knight with a threat of its own, and the rook on c8 is lost if they answer the knight. These are easier to miss because the board does not shout "check."

Scan them the way you scan forks. After you notice a battery — two of your pieces on one line, aimed at an enemy piece — look at every legal move of the front piece. One of them is often a capture that comes with tempo.

How not to allow it

Do not sit your king or queen on a line that already contains an enemy bishop or rook, even if one of their pieces currently blocks that line. The block is temporary. They will move it when the move hurts you. Step off the line, or trade the piece that is waiting behind.

In your own games, a discovered check you did not see usually means the king was left on an open diagonal after a pawn trade. When a center pawn leaves the board, recheck every diagonal into your king before you continue the plan.

Frequently Asked Questions

Can I capture the piece that gives the discovered check?

You can capture the piece behind if it is the only checker and the capture is legal. In a double check you cannot. The king has to move.

Does the front piece have to give check as well?

No. In an ordinary discovered check the front piece can do anything, including capture an unprotected queen. Only a double check requires both pieces to attack the king.

Are discovered attacks only a middlegame idea?

They show up whenever two of your pieces share a line. Endgames with a rook behind a pawn, and a king that steps off the file with check, are the same pattern.

Move the screen, keep the shot

Batteries win material because one move creates two threats. Combine them with forks and you have the two tactics that punish loose pieces most often. Set the position up if you want the line checked with chess hints.

Solve a puzzle Analyze a position

Try the line on the board with chess hints.