A typical line of play where Black plays an early ...d5 is 1.c4 c5 2.Nc3 Nf6 3.Nf3 d5, when White usually trades off in the centre 4.cxd5 Nxd5. White can either challenge the centre with 5.d4 or 5.e4 or allow Black a space advantage in the centre with 5.g3.