Most likely he will play the Ruy Lopez. We need to decide which line we want in that - if we screw up the moves, he'll retain a huge advantage.
As predicted by actmyname, we're dealing with the Ruy Lopez or Spanish Game.
Several options are available, including:
3...a6 (Morphy Defence)
3...Nf6 (Berlin Defence)
3...Bc5 (Classical or Cordel Defence)
3...Nge7 (Cozio Defence)
3...g6 (Smyslov Defence)
3...Nd4 (Bird's Defence)
3...d6 (Steinitz Defence)
3...f5!? (Schliemann Defence or Jaenisch Gambit)
I vote for a6. What do you think?
a6: 1 vote (hermesesus)