Category - Closed Game
Opening Move Sequence - 1 d4 d5, 2 c4 e6
ECO Codes - D30 to D69
Queen's Gambit Declined which is usually refereed to by abbreviation QGD, can technically be applied to any Queen's Gambit opening that does not contain 2 ... dxc4. However the term is usually applied only to the variations in Queen's Gambit that starts with 2 ... e6. This is because of the large number of variations that flow from it. Other variations starting from different second moves for Black such as Symmetrical Defense (2 ... c6), Slav Defense (2 ... c6), Chigorin Defense (2 ... Nc6), Albin countergambit (2 ... e5), Baltic Defense (2 ... Bf5), and Marshall Defense (2 ... Nf6), some of which can be quite intricate and rich in their own right.
Positions in Queen's Gambit Declined can be reached from other openings as well. For example after 1 d4 Nf6, 2 c4 e6, 3 Nf3 d5, 1 c4 e6, 2 Nc3 d5, 3 d4, or 1 Nf3 d5, 2 c4 e6, 3 d4.
Queen's Gambit Declined falls under the category of Closed Game openings that begin with 1 d4 d5. Its ECO codes range from D30 to D69.
Moves and Variations
1 d4 d5
2 c4 e6
Move 2 ... e6 allows Black to establish a strong defensive position and maintain the stake in the center instead of relinquishing it by accepting the pawn. This makes it one of the, most dependable defenses for Black in chess. One of the main apparent weaknesses of 2 ... e6 is that c8 Bishop is prevented from developing. White may try to benefit from this, so Black can attempt to develop it or exchange it. However it must be realized that Bishop does play a crucial part in Black's defensive position even from its original square in this opening.
Another point to note is that as long as c4 exists the tension in center will remain. If Blacks decides to play dxc4 and lose control in center later, he needs to get something in return. For instance Black can force White to lose a move by playing dxc4 after White's Bd3. Black can then attack the White's center by c5 and e5. On the other hand if White decides to act by playing cxd5 Black can reply by exd5 which will give Black preponderance of pawns in Queen-side and White a majority in the center. White will then try to launch attack from center while Black can now make use of now unblocked c8 Bishop and open e-file to attack White.
White main replies to 2 ...e6 are 3 Nc3 or 3 Nf3. Black has several possibilities at this point
The reply 3 ... Nf6 is the main variation of Queen's Gambit Declined and is called Orthodox Defense but that term is also applied to one specific variation of it as well (see below). There are several variations under 3 ... Nf6. Sequence 4 Bg5 Be7, 5 e3 0-0, 6 Nf3 h6, 7 Bh4 b6, leads to Tartakower Defense with defensive play for Black. 4 Bg5 Be7, 5 e3 h6, 6 Bh4 Ne4, called the Lasker Defense is similar but may involve exchange of minor pieces. 4 Bg5 Nbd7, 5 Nf3 c6, 6 e3 Qa5, is called Cambridge Springs Defense and allows possibility of several traps. Orthodox Defense sharing name with it parent continues 4 Bg5 Be7, 5 Nf3 c6, 6 e3 0-0, 7 Rc1 Nbd7, 8 Bd3 dxc4, 9 Bxc4, and implements several things outlined above. 4 cxd5 exd5, known as Exchange Variation rapidly leads to a fixed pawn skeleton.
Without 3 ... Nf6
In case of 3 ... c6 the game enters Semi-Slav Defense and resembles other lines of Queen's Gambit Declined. If 3 ... c6 the opening is called Tarrasch Defense. Black is risking an isolated d pawn for certain advantages. The move 3 ... Be7 leads to variations that can be transformed to variation under 3 ... Nf6 while sidestepping the Exchange Variation. For example if Black wants to avoid the possibility of a 5 Bg5 pin, after 3 ... Nf6, 4 cxd5 exd5, he can use 3 ... Be7 to bypass the Exchange Variation.
