The Queen's Gambit Declined arises after 1.d4 d5 2.c4 e6. ECO codes: D30–D69.

The classical response—Black declines the gambit with ...e6, supporting d5 solidly. This is the most common and important line of the Queen\'s Gambit. The Orthodox Defence (3.Nc3 Nf6 4.Bg5 Be7), Tartakower Variation, Lasker Defence, and Cambridge Springs are among the most important sub-systems. The QGD is one of the oldest and most trusted defences in chess.