Discovered Check

Discovered check is the specific case of a discovered attack where the piece "uncovered" behind the moving piece gives check rather than merely attacking another piece. Chess writer Howard Staunton distinguished the three related concepts precisely in his 1876 book Chess: Theory and Practice, defining check, discovered check, and double check as increasingly forcing variations on the same underlying mechanism — a distinction that has remained essentially unchanged in chess instruction for a century and a half since. The power of a discovered check comes from forcing sequence: because the opponent's king must respond to the check before anything else, the piece that moved to create the discovery effectively gets a free additional action, able to capture material, deliver a second attack, or reposition for a follow-up mating threat with no immediate reply possible.