Dutch defence
1. d4 f5 2. c4 Nf6 3. g3 e6 4. Bg2 Be7
White moves the queen's pawn to d4. Black pushes the f-pawn to f5. White plays the c-pawn to c4.
Black develops the knight to f6. White pushes the g-pawn to g3. Black advances the king's pawn to e6.
White develops the light-squared bishop to g2. Black develops the dark-squared bishop to e7.