1.Nf3 f6 2.Nc3 c6 3.e4

Black can play:

3...e6,

3...g6 4.Nd4 Nh6,

3...h5,

3...d5 4.Nb5 cxb5 (4...dxe4) 5.Bb5 Nc6 6.d4,

3...d6 4.Ng5 fxg5 5.Nd5 cxd5 6.Qh5 g6 7.Qb5 Nc6 8.Qb6 axb6 9.Bb5 Kf7 10.Be8 Ke6.