Key ideas
- After 2.e5 Nd5, White can chase the knight with c4 and d4. The Four Pawns Attack (with f4 as well) is the most ambitious answer.
- Quieter systems such as the Modern Variation (4.Nf3) give White a smaller but steadier edge.
Plans for White
Gain space but keep the pawns protected. Overextension is exactly what Black wants.
Plans for Black
Undermine the pawn centre with ...d6, ...c5 and piece pressure.

