 Among the many possibilities in the Queen's Gambit Declined are the Orthodox Defense, Lasker's Defense, the Cambridge Springs Defense, the Tartakower Variation, and the Tarrasch and Semi-Tarrasch Defenses.Black replies to the Queen's Gambit other than 2...dxc4, 2...c6, and 2...e6 are uncommon.The Colle System and Stonewall Attack are classified as Queen's Pawn Games because White plays d4 but not c4.