Ruy Lopez - Berlin defence - open variation
1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. O-O Nxe4
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 develops the light-squared bishop to b5. Black jumps the knight to f6.
White castles kingside. Black captures with the knight on e4.