Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nf6/3. Nxe5/3...Nc6/4. Nxc6/4...dxc6/5. e5/5...Ne4/6. f3

=Stafford Gambit=

6.f3??
6. f3 is a tempting move to kick out the knight from the center, but allows a devastating check from Black. After 6...Qh4+, 7.Ke2 immediately loses with a forced checkmate (see below). The other option is 7.g3 Nxg3, losing a rook for a knight and destroying the kingside.