A discovered attack is when you move one piece out of the way so that a different piece behind it suddenly attacks an enemy target.
Two of your pieces line up behind each other on the same rank, file or diagonal, with the front one masking the rear one. When the front piece moves, the rear piece’s attack is ‘discovered’ — and the front piece can do its own damage on the way, so you make two threats with one move.
The strongest version is the discovered check: the unveiled piece gives check, which must be answered, while the moving piece grabs something for free. Because the opponent has to deal with the check first, they can’t save the second target.
Discoveries are pure tempo: you attack two things at once with two different pieces, so they’re among the hardest tactics to defend. Train yourself to notice when your own pieces are stacked behind a movable piece.
A discovered attack where the piece that gets unveiled gives check. It’s especially powerful because the opponent must respond to the check, letting the moving piece capture something for free.
A fork is one piece attacking two targets. A discovered attack uses two pieces — the one that moves and the one it unmasks — to create two threats in a single move.
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