Scotch Gambit, Advance Variation

Instead of castling first, White pushes 5. e5 straight away. This gains space, drives the knight off f6, and keeps the d4-pawn under attack. Older sources call this the modern treatment, as opposed to the classical 5. O-O. The same position arises from the Two Knights Defense via 3. Bc4 Nf6 4. d4 exd4 5. e5. The engine considers it balanced, and White scores slightly better than Black in online play.

The most common reply, 5...d5, strikes back in the center and hits the bishop. It is also Black's best-scoring choice. After 6. Bb5 Ne4 7. Nxd4 Bd7 8. Bxc6 bxc6 9. O-O Bc5 10. f3 Ng5, White has the pawn back, and Black has the bishop pair and a centralized position to set against the weakened queenside pawns. The Kingside Variation, 5...Ng4, sends the knight toward the e5-pawn instead and is the second most frequent move. White does better against it in practice. The centralizing 5...Ne4 is the third main option and is also among the engine's preferred replies.