An opening variation where the opponent is tempted to play a bad move
An opening trap is where the opponent facing the trap is tempted to play a superficially pleasing, but bad move. For example, we can call Scholar's mate a trap. White plays an inaccurate move, hoping that Black will play 3...Nf6??, attacking the queen, but it fails to 4. Qxf7 checkmate.
Opening traps may also come at chance. A normal developing move is incorrect for some reason or another. As an example, the Siberian Trap in the Smith-Morra gambit.