Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bc4/3...Nf6/4. O-O

=Italian Game, Two Knights Defence=

4. O-O
White sacrifices a pawn for a lead in development and king safety. This is not the soundest line in the Italian Game, but completely playable.

'''1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. O-O'''