Discovery
The Discovered Check
A discovered check is a discovered attack in its sharpest form: the revealed piece delivers check to the enemy king. Because the opponent is legally obliged to answer the check first, the piece that moved away is free to roam almost anywhere, even snatching material, with total impunity. The forcing nature of check makes this one of tactics' most devastating tools.
1. Nxc4+ Kf8
The Motif
In a discovered check, the piece that steps aside reveals a check from a piece behind it. The check is the immediate emergency: the opponent must get out of check before doing anything else. This gives the moving piece extraordinary freedom, since it is no longer bound by the usual rules of trade and defense.
That freedom is the whole point. The mover can travel to a distant square, capture an undefended unit, or set up a further threat, and the opponent simply cannot object because the revealed check demands an immediate reply. Grabbing the enemy queen this way is a classic and brutal application of the idea.
The Line
White plays 1.Nxc4+. The knight captures the black queen on c4, and as it leaves e5 it opens the e-file so the rook on e1 checks the king on e8. The knight's move and the rook's check happen together, but only the check compels a response from Black.
Black must deal with the check, and after 1...Kf8 the king steps off the e-file to safety. Crucially, Black never had a moment to recapture the knight, because addressing the check came first. White has simply pocketed the queen and stands a whole queen up with an easily winning position.
Key ideas
- A discovered check reveals check from the piece left behind.
- The opponent must answer the check before anything else.
- This lets the moving piece capture or relocate freely.
- Here Nxc4+ takes the queen while unmasking the rook's check.
- Black must move the king with Kf8 and cannot recapture.
- The knight keeps its prize, leaving White a queen ahead.