As Black
Petroff Defence
Instead of defending e5, Black counterattacks e4. Very solid: symmetrical positions where it is hard to lose.
Lines
Steinitz Attack: 3.d4
1.e4 e5 2.Nf3 Nf6 3.d4 Nxe4 4.Bd3 d5 5.Nxe5 Nd7 6.Nxd7 Bxd7 7.O-O Bd6
Against 5.Nc3
1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.Nc3 Nxc3 6.dxc3 Be7 7.Be3 O-O 8.Qd2 Nd7 9.O-O-O Nf6
Against 3.Bc4
1.e4 e5 2.Nf3 Nf6 3.Bc4 Nxe4 4.Nc3 Nxc3 5.dxc3 f6
Classical line
1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.d4 d5 6.Bd3 Nc6 7.O-O Be7 8.c4 Nb4
Against 3.Nc3
1.e4 e5 2.Nf3 Nf6 3.Nc3 Nc6 4.Bb5 Bb4 5.O-O O-O 6.d3 d6