1. d4 d5
2. c4 e6

The most popular response to the Queen’s Gambit is to decline it with 2… e6, defending the pawn on d5 and maintaining a solid pawn presence in the centre. The Queen’s Gambit Declined, or QGD, has developed an enormous body of theory, and books could be (and have been) filled with analysis of just this opening.

The QGD gives black a solid, defensible position. Its big disadvantage is that the pawn on e6 blocks black’s queen’s bishop, and it can be very difficult to find a way of freeing that bishop.

The traditional main line is 3. Nc3 Nf6 4. Bg5 Be7 5. e3 0-0 6. Nf3 (see diagram below). At this point, the Orthodox Defence, 6… Nbd7, is a solid choice, but requires black to play quite patiently and doesn’t offer many active counterchances. The Tartakower Variation is a more active alternative: 6… h6 (chasing away the bishop) 7. Bh4 8. b6 and black prepares to “fianchetto” the problematic queen’s bishop to b7. The Lasker Variation, in which black again chases away the white bishop but then plays 8. Ne4, is another solid line.

Another key alternative for black is the Tarrasch Defence, which was championed by the great player and theorist Siegbert Tarrasch in the late 19th and early 20th centuries, though it was denounced as unsound by many of the other great players of the day. After 3. Nc3, the Tarrasch Defence is 3… c5. It gives black immediate mobility and attacking chances, but at the cost of a weak pawn structure; black usually winds up with an isolated d-pawn, which white can attack with great advantage.

A major alternative available for white is to trade pawns in the centre, for instance 3. cxd5 exd5 (though it’s also possible to delay the trade until a later move). These are collectively known as the Exchange Variation, and the idea for white is to clear space for either a pawn push on the queenside or an attack on the kingside. The disadvantage is that white has relieved black of their main problem: freeing the queen’s bishop.

These are, of course, only a few of the more common variations in the QGD, which has been and continues to be one of the most studied chess openings.