Key ideas
- 5.Nxf7 Bxf2+ is the critical line. After 6.Kxf2 Nxe4+ the king is driven into the open: 7.Kg1 is the safest square, though it shuts in the h1 rook, while 7.Ke3, the King March, leads to very sharp play.
- After 7.Kg1 Qh4 Black threatens ...Qf2#, so White must defend with 8.g3 or a similar move before collecting the rook on h8.
- Many players see 5.Bxf7+ as White's most reliable answer. After 5...Ke7 the bishop retreats, usually to d5 or b3, and White keeps an extra pawn while Black uses the half-open f-file and quick development with ...Rf8 and ...d6.
- Black's targets are f2 and the e4 pawn. The knights head for e4 and d4, the queen comes to h4, and the rook joins along the f-file.
Plans for White
If you take on f7 with the knight, know the king moves and the defensive resources. If you prefer safety, 5.Bxf7+ Ke7 followed by a bishop retreat keeps an extra pawn and a calmer game; then castle and develop with c3 and d3 or d4.
Plans for Black
Play fast, because every tempo counts. ...Qh4, ...Rf8, ...d5 and ...Nd4 bring pieces into the attack, and material matters less than keeping White's king in the open.
Watch out
After 5.Nxf7 Bxf2+ 6.Kxf2 Nxe4+ 7.Kg1 Qh4, the greedy 8.Nxh8?? allows 8...Qf2#.
For the wider picture, see the Italian Game guide.