Queen's Gambit Declined: Exchange Variation, Chameleon Variation

The Queen's Gambit Declined: Exchange Variation, Chameleon Variation is a chess opening classified under ECO code D35 in the Closed & Semi-Closed Games family, arising from 1.d4 d5, including the Queen's Gambit, Slav Defense, and related systems. It is reached after 10 moves: 1. d4 Nf6 2. c4 e6 3. Nc3 d5 4. cxd5 exd5 5. Bg5 Be7 6. e3 O-O 7. Bd3 Nbd7 8. Qc2 Re8 9. Nge2 Nf8 10. O-O-O. The resulting position leaves black to move.