Ruy Lopez with 3...d5?! (from 1.e4 PGN)
Main idea: after 3...d5?!, use the pin on the c6 knight. White plays Nxe5 and Nxc6 to win a pawn and then keeps developing pieces to safer squares.
Opening moves: 1. e4 e5 2. Nf3 Nc6 3. Bb5 d5?!. Black tries to strike in the centre too quickly and forgets that the c6 knight is pinned.
White calmly takes the pawn on e5 and then on c6, winning material while staying ahead in development. This page follows the 1.e4 repertoire PGN and explains why 3...d5 is a mistake.
Main idea: after 3...d5?!, use the pin on the c6 knight. White plays Nxe5 and Nxc6 to win a pawn and then keeps developing pieces to safer squares.