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

= Slav Defence =

3.Nc3
This move develops a piece and bears more pressure on d5. Due to this, it also makes 3...Bf5 a grave mistake due to 4. cxd5 cxd5 5. Qb3, winning a pawn. If then 5...Qb6, 6. Nxd5! Qxb3 7. axb3! wins the d pawn. If instead 5...Nf6 to protect the d pawn, 6. Qxb7 Nbd7 7. Nf3 Rb8 8. Qxa7 wins two. In general, if black can safely play Bf5 and e6 in the Slav, he equalizes. Also, it prepares an e4 advance in the center. However, the knight is vulnerable here to a b7-b5-b4 advance, so ...dxc4 and ...b5 are often played.

Theory table
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'''1. d4 d5 2. c4 c6 3.Nc3'''