Queen's Gambit Declined (Black)
Davies' one-setup answer to 1.d4: ...Nf6, ...Be7, ...Nbd7 and ...c6 against everything. The oldest, soundest defence in chess: played by every world champion.
Step through the main line
The lines
Main Line with Bg5
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 Be7 5. e3 O-O 6. Nf3 Nbd7 7. Rc1 c6 8. Bd3 dxc4 9. Bxc4 Nd5
Exchange Variation with Nf3
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. cxd5 exd5 5. Bg5 Nbd7 6. e3 Be7 7. Bd3 c6 8. Nf3 O-O 9. Qc2 Re8 10. O-O Nf8 11. h3 Ne4
Exchange Variation with Nge2
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. cxd5 exd5 5. Bg5 Be7 6. e3 c6 7. Bd3 Nbd7 8. Qc2 O-O 9. Nge2 Re8 10. O-O Nf8
Main Line with Bf4
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Nf3 Be7 5. Bf4 O-O 6. e3 Nbd7 7. Bd3 dxc4 8. Bxc4 Nd5 9. Bg3 b6
The Catalan (Open)
1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 Be7 5. Nf3 O-O 6. O-O dxc4 7. Qc2 a6 8. Qxc4 b5 9. Qc2 Bb7
The Tartakower Defence
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 Be7 5. e3 O-O 6. Nf3 h6 7. Bh4 b6 8. cxd5 Nxd5
The Lasker Defence
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 Be7 5. e3 O-O 6. Nf3 Ne4 7. Bxe7 Qxe7 8. cxd5 Nxc3
How this guide is made: the lines and explanations come from the authored Strong Squares repertoire curriculum. Automated checks verify legal move sequences and required teaching fields. Independent chess-editor approval remains a private-preview release gate. Read the teaching method.