Discovered attack: pawn to c5 (c4)

Types in this puzzle

Discovered check

The moving piece opens a check — and is free to grab anything meanwhile.

With a discovered check the moving piece unmasks a check from the piece standing behind it. While the king deals with the check, the piece that moved grabs whatever it likes, free of charge. Look for your long-range piece on a line with the enemy king, with exactly one of your own pieces in between. The rule: among all the ways to step aside, pick the one that captures or attacks the most expensive loot.

Only move

Everything else loses — find the only move that holds.

An only move is a position where everything loses except one single continuation. You cannot play "by hand" here: run through fundamentally different defenses — run away, block, trade, counterattack — and discard the ones that fail. The hallmark of these puzzles is that the obvious moves lose quickly while the solution often looks strange. First understand exactly what the threat is — then the one saving move reveals itself.

Blocking save

Block the check with tempo — and turn the game around.

The blocking save: you interpose a piece against the check — not passively, but with tempo, so the blocker creates a threat of its own. Such a block turns defense into attack. Whenever you are checked, compare all three replies — capture, move the king, interpose — and among the interpositions hunt for the one that counterattacks. The mistake is automatically stepping aside with the king when an active block would have turned the game around.