Chess Opening Theory/1. d4/1...d5/2. c4/2...c6/3. Nc3/3...dxc4

This move captures the gambit pawn. Since White's Knight on c3 is exposed to attacks by Black's b-pawn, black can often safely over-extend with moves like a6 and b5 to keep ahold of the c-pawn in this line. This move is lesser seen than the main line 3. Nf6. From here, white has several replies:

• e4 - The most common reply, White gains a significant space advantage in the center but White's c3 knight loses access to e4 as a retreating square.
• e3 - Slightly less common, White still advances in the center, but keeps the e4 square open for the c3 knight to retreat to.
• a4 - Uncommon, white prevents Black's ...b5, but allows black to fight in the center with e5. Black tends to do well in this variation.
• Nf3 - Uncommon, white focuses on development with their g1 knight.

There is a trap following 4.e3 b5, where the move 5. Nxb5?, trying to exploit the h1-a8 diagonal is a mistake which gives black the advantage after 5...cxb5 6.Qf3 Qc7! 7.Qxa8 Bb7 as white has to sacrifice material in order to avoid black winning the Queen.

1. d4 d5 2. c4 c6 3.Nc3 dxc4