Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5

3. Bb5 - Spanish Game
The essential move marking the Spanish Game, or Ruy Lopez. "It is the double king's pawn opening most commonly used in master play; it has been adopted by almost all players at some point in their careers and many play it from both the White and Black sides."

White threatens to trade off Black's c6-knight, leaving the e5-pawn undefended. It's not an immediate threat, because after 4. Bxc6 dxc6 5. Nxe5, Black can win the pawn back with 5... Qd4 or 5... Qg5.

Black can respond in a variety of ways. The most common move is the Morphy Defence 3... a6. This forces White to make a decision about the Bishop - retreat or exchange.

Many other moves are available, some neglecting completely the protection of the knight and the pawn and continuing development.

The opening is named after the 16th century Spanish priest Ruy López de Segura. The popular continuation is: 3... a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 O-O 8. c3 d5 9. exd5 Nxd5 10. Nxe5 Nxe5 11. Rxe5 c6 12. d4 Bd6 13. Re1 Qh4 14. g3 Qh3.

Theory table

 * 1. e4 e5 2. Nf3 Nc6 3. Bb5