Irish (Chicago) gambit
1. e4 e5 2. Nf3 Nc6 3. Nxe5 Nxe5 4. d4
White plays the king's pawn to e4. Black advances the king's pawn to e5. White develops the knight to f3.
Black develops the knight to c6. White captures with the knight on e5. Black captures with the knight on e5.
White moves the queen's pawn to d4.