Philidor - Lopez counter-gambit
1. e4 e5 2. Nf3 d6 3. Bc4 f5
White advances the king's pawn to e4. Black advances the king's pawn to e5. White develops the knight to f3.
Black moves the queen's pawn to d6. White develops the light-squared bishop to c4. Black plays the f-pawn to f5.