Discovered Check
A discovered attack where the revealed piece delivers check, giving the moved piece a free hand.
Published 2026-02-01 | Last verified 2026-02-12
Professor Archer says: I sometimes describe the discovered check as the "pickpocket" of chess tactics. While the king is busy dealing with the check, the other piece helps itself to whatever it wants on the board. It is one of those moments where you get to break the normal rules of fair play — your opponent must respond to the check, and meanwhile, your other piece is free to do whatever it pleases. When I first understood this principle, it felt like discovering a secret passage in a familiar building.
Why Discovered Checks Are So Powerful
A discovered check combines two powerful ideas: the discovered attack and the forcing nature of check. In a standard discovered attack, the opponent faces two threats and must choose which one to address. In a discovered check, that choice is removed — check must be answered first, always, without exception.
This means the piece that moved has essentially received a free move. It can go anywhere on the board: capture the queen, take a rook, land on a dominant central square, or set up a mating threat. The opponent cannot respond to any of this until the check is dealt with. By the time they resolve the check, the damage is done.
Consider the mathematics of it. In a normal sequence of moves, each player alternates turns. But a discovered check effectively gives you two moves in a row — the moving piece does something productive, and the opponent's reply is consumed by the check. This tempo advantage is often decisive.
Discovered checks are especially common in the middlegame, when many pieces are on the board and the lines between them create opportunities for discovery. They also appear in the endgame, particularly when a bishop or rook can be unmasked against the enemy king.
The key to finding discovered checks is awareness of piece alignment. Any time one of your pieces stands between your line piece and the enemy king, you should ask: what happens if my front piece moves? If the answer involves check from the piece behind, you may have a winning tactic.
Discovered Check in Practice
Let us examine a common discovered check pattern. In the position shown, White has a bishop on b5 that is already aimed at the Black king on e8, with a knight on the d-file that could potentially move to discover the check.
Imagine the knight moves from d4 to f5 or c6. The knight clears the diagonal from b5 to e8, and suddenly the bishop delivers check. Black must deal with the bishop check — perhaps by blocking on d7 or moving the king. Meanwhile, White's knight on its new square may be attacking a valuable black piece, which Black cannot protect this turn because they are busy answering the check.
This is the essence of the discovered check: one move creates two problems, but the opponent can only solve one. The check consumes their turn, and the other threat goes unaddressed.
In many opening variations, particularly in the Ruy Lopez and Italian Game, the bishop on b5 or c4 naturally aligns with the enemy king. Any piece that stands on the b5-e8 or c4-f7 diagonal becomes a potential discovery piece. Grandmasters are always aware of these alignments and look for moments to exploit them.
When you are calculating a discovered check, always verify two things: first, that the check cannot be blocked in a way that also addresses your other threat; second, that the square where your moved piece lands is safe.
The bishop on b5 is aimed at the king on e8. If the knight on the diagonal moves, a discovered check is unleashed.
Famous Discovered Check Combinations
Some of the most brilliant combinations in chess history have featured discovered checks as their centerpiece. These moments illustrate the sheer power of this tactic when wielded by creative minds.
One classic pattern is the "windmill," where a piece moves back and forth, discovering check each time and capturing a new piece with every move. The most famous windmill occurred in the 1925 game between Torre and Emanuel Lasker. White's rook and bishop worked together to deliver discovered checks repeatedly, with the rook capturing a new piece each time it moved. The opponent could do nothing because every single move was check.
Another common pattern in master games involves sacrificing material to set up a discovered check. A player might give up a piece to lure the enemy king onto a specific diagonal, then move a piece to discover a check that wins back far more material. These combinations require deep calculation but are enormously satisfying when they work.
The discovered check also plays a crucial role in many endgame studies and composed chess problems. The interplay between the moving piece and the uncovered piece creates rich tactical possibilities that have fascinated chess composers for centuries.
Studying these famous examples is one of the best ways to train your tactical eye. When you see how masters use discovered checks, you begin to recognize similar patterns in your own games.
Defending Against Discovered Checks
Defending against discovered checks requires awareness and prevention, because once the check is delivered, the damage is often already done.
The most important defensive principle is avoiding dangerous alignments. If your king stands on the same diagonal, rank, or file as an enemy line piece, and there is an enemy piece between them, you are vulnerable to a discovered check. Recognize these alignments early and take steps to break them.
Castling is one of the best preventive measures. By tucking the king away behind a wall of pawns on the kingside or queenside, you take it off the center files and diagonals where most discovered checks occur. Early castling is especially important against aggressive openings that aim for quick tactical strikes.
Another defensive technique is to avoid leaving pieces on the discovery line. If you notice that an enemy piece is blocking a line to your king, think about what happens if that piece moves. If the answer is a devastating discovered check, you need to act preemptively: move your king, block the line, or eliminate one of the pieces involved in the potential discovery.
When a discovered check is imminent, sometimes the best defense is a counter-threat. If you can create a threat that is more urgent than the discovered check (such as threatening immediate checkmate), your opponent may be forced to abandon their planned discovery. This requires sharp calculation but can save seemingly hopeless positions.
Frequently Asked Questions
What is a discovered check in chess?
A discovered check is a type of discovered attack where the piece revealed behind the moved piece delivers check to the enemy king. Because check must be answered immediately, the moved piece effectively gets a free move to go anywhere, often capturing a valuable piece or creating a devastating threat.
How do you set up a discovered check in a game?
Position one of your line pieces (bishop, rook, or queen) on the same rank, file, or diagonal as the enemy king, with one of your other pieces between them. When the blocking piece moves to a productive square, the line piece reveals a check on the king.
Professor Archer says: The discovered check teaches an important chess lesson: the most dangerous threats are the ones your opponent cannot address immediately. Every time you force your opponent to deal with check, you gain a free tempo to improve your position. Master this concept, and you will win many games through sheer tactical force.
Quick Quiz
Why is a discovered check more powerful than a regular discovered attack?
- It involves more pieces - Both a discovered check and a regular discovered attack involve the same number of pieces. The difference lies in the type of threat, not the number of pieces.
- The opponent must answer the check, giving the moved piece a free move (Correct) - Correct. Because check must be answered immediately, the opponent cannot deal with whatever the moved piece is doing. This effectively gives the attacker two threats for the price of one, with the check consuming the defender's response.
- It always leads to checkmate - Discovered checks do not always lead to checkmate. They often win material, but the outcome depends on the specific position.
- It can only be performed by a queen - Any line piece (bishop, rook, or queen) can deliver the discovered check, and any piece at all can be the one that moves to reveal it.