Queen's Gambit Declined - Charousek (Petrosian) variation
1. d4 d5 2. c4 e6 3. Nc3 Be7
White pushes the queen's pawn to d4. Black pushes the queen's pawn to d5. White pushes the c-pawn to c4.
Black pushes the king's pawn to e6. White develops the knight to c3. Black develops the dark-squared bishop to e7.