A discovered check happens when you move a piece out of a line and uncover a check from a bishop, rook or queen behind it. The opponent has to answer the check, which leaves the piece that moved free to do almost anything it likes. The puzzles on this page come from real games, are matched to your puzzle rating, and all involve a discovered check.
A discovered check is the most forcing kind of discovered attack. With an ordinary discovery the opponent can choose which threat to meet. With a discovered check they have no choice at all: they must get out of check first. Whatever the moving piece attacks, captures or threatens is usually lost.
It also means the moving piece can go to a square where it would normally just be captured, because the opponent has no time to take it. A knight can land next to the enemy queen, a rook can take a defended piece, and the check still has to be answered first.
A classic trap in the Petrov Defence shows it cleanly. After 1.e4 e5 2.Nf3 Nf6 3.Nxe5 Nxe4 4.Qe2 Nf6, Black has copied White once too often. White plays 5.Nc6+. The knight leaves the e-file, so the queen on e2 now gives check to the king on e8, and at the same time the knight attacks Black's queen on d8.
Black's only legal replies are the blocks 5...Qe7, 5...Be7 and 5...Ne4. After each of them White captures the queen next move. Taking the knight is not possible, because the knight is not the piece giving check and capturing it would leave the king in check. The usual move is 3...d6 first, driving the knight back before taking on e4.
Look for your own bishop, rook or queen pointing at the enemy king with exactly one of your pieces in between. That piece is the trigger. Any legal move it makes off the line gives check, so the only question is where it does the most damage: a capture, an attack on the queen, a fork, or a second check.
Any piece can be the trigger, even a pawn or your own king, as long as it moves off the line. When the trigger also gives check from its new square, you have a double check, which is stronger still.
The same pattern can repeat. A rook and bishop that take turns giving discovered check can work like a windmill: each time the king steps aside, the rook captures another piece and returns with check again. The famous example is Torre against Emanuel Lasker in Moscow, 1925.
The most common is moving the trigger to a quiet square and wasting the check. With a discovered check you usually have time for the biggest capture on the board, so look for it. The second is not checking whether the check can be answered by a block or capture that gains time, for example a block with a piece that also attacks your trigger. The third is on defence: leaving your king on a line with an enemy line piece behind one of the opponent's pieces.
When a puzzle starts, trace every line from your bishops, rooks and queen to the enemy king. If one of your pieces blocks that line, try each of its moves in your head, starting with the captures. If you are stuck, the hint shows the piece first, then the move; here that is usually the trigger. After you solve, the full line appears beside the board.
For mixed tactics at your level, use Puzzle Training. Puzzle Storm trains speed, the Woodpecker Method repeats a fixed set until it is automatic, Elo Maxing serves the motif you are weakest at, and Pattern Drill works from positions in your own games. Related pages: discovered attacks, double check and pins, since a piece pinned to its king is the defender's version of the same line. For solving under the clock, read puzzle rush tips.
A check given by a bishop, rook or queen when one of your own pieces moves out of its line. The piece that moved is free to make a threat of its own.
A discovered attack uncovers a threat to any piece. A discovered check uncovers a threat to the king, so the opponent must deal with it before anything else.
Only if that capture also deals with the check. Usually it does not, because the check comes from the piece behind.
The checking piece is always a bishop, rook or queen. The piece that moves out of the way can be any piece, including a pawn or the king.