Scholar's mate (1.e4 e5 2.Qh5 Nc6 3.Bc4 then 4.Qxf7#) targets the f7-pawn for a four-move checkmate. It works against players who don't know it, but it's easily defended — for example 3...g6 hitting the queen, or 3...Qe7 defending f7 — and the early queen sortie loses time if it fails. Don't rely on it.