Two Knights Defence

With 3...Nf6, Black develops a knight and attacks the e4-pawn, getting one step closer to castling. This move seems like the most obvious one Black can play in the Italian, but it also comes at a disadvantage of blocking the d8-h4 diagonal of the black queen.

White has several ways to proceed from this position:

The e4-pawn is attacked, so the most logical move for white would be to defend it.

4. d3 is the most common move to the Two Knights Defence, defending the pawn and opening the c1-h6 diagonal for the dark squared bishop. This is known as the Modern Bishop's Opening, and usually results in Black either transposing to the Giuoco Pianissimo with 4...Bc5, or Black continuing in Ruy Lopez-style development with 4...Be7.

4. Nc3 looks like a logical move to defend the pawn, but it allows Black the opportunity to play 4...Nxe4! This is the common Center Fork Trick, in where Black temporarily sacrifices a piece in order to play d5 and get back the piece with a comfortable position.

White can take advantage of the fact that 3...Nf6 blocked the queen's protection of g5 with the move 4. Ng5, entering the Knight Attack. With this move, White double attacks the f7-pawn, and also takes advantage of the fact that Black has not developed the f8-bishop and cannot react to this attack by castling. This usually results in Black sacrificing a pawn to block the bishop and achieve a lead in development with 4...d5 5.exd5.

White can also open up the center with 4. d4, which almost always transposes to the Scotch Gambit after 4...exd4. White can then either continue with 5. O-O, playing aggressively in gambit-style fashion, or can gain more space in the center with 5. e5.

White can also gambit the e4-pawn with 4. O-O, intending to meet 4...Nxe4 with 5. Nc3, where White sacrifices a pawn for a rapid lead in development and threats against Black's uncastled king.

For explanation of theory tables, see theory table and for notation, see algebraic notation..

1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6

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Wikipedia has related information at Two Knights Defence

• The Two Knights Defence (1983) Yakov Estrin. ISBN 0-7134-3991-2.
• Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.

• Nunn's Chess Openings. 1999. John Nunn (Editor), Graham Burgess, John Emms, Joe Gallagher. ISBN 1-8574-4221-0.