An opening trap is a sequence of moves in the early game designed to lure the opponent into a specific mistake, resulting in a decisive advantage — often material gain or even a quick checkmate.
These traps work through deception: the move that sets the trap looks harmless or even attractive for the opponent, while concealing an immediate refutation. A classic example is Legal’s Trap (also known as Legal’s Mate), where White appears to blunder their queen, only to deliver a smothered mate with the minor pieces.
In practice, opening traps cut both ways. They can catch an unprepared opponent off guard and lead to a quick win. However, against a player who knows the correct response, the one setting the trap often ends up in a worse position. At your level, learning a few common traps in your regular openings is worthwhile — but never build your entire repertoire around them.