Threat

A threat states what a player intends to do next if the opponent takes no preventive action. It may announce mate, an attack on the king with no legal defense, a favorable capture, pawn promotion upon reaching the last rank and becoming another piece, a fork in which one piece attacks several targets, or the trapping of a piece. To be real, it needs a concrete consequence and a continuation that works against reasonable replies.

Attack and threat are not identical. In the formal rules sense, a piece attacks a square when, according to its movement, it would capture an opposing piece placed there, even if it cannot actually make that capture because doing so would leave its own king in check; the attack may still be harmless because the target is adequately defended. A threat instead means that allowing the idea causes meaningful damage. Check is a special case: it attacks the king now and requires an immediate response, while other threats may be ignored legally, although usually unwisely.

Strong threats restrict choices and help preserve the initiative, the ability to pose problems that require answers. A defender may prevent the idea, move the target, exchange the attacker, or create more urgent counterplay, a threat of their own that demands attention. In tactical play, concrete short-range play, naming the exact threat prevents defending the wrong thing.