About this opening
Queen's Gambit Declined: Semmering Variation is an opening in the Encyclopedia of Chess Openings,
classified under code D30. ECO group D (D00–D99)
covers closed games and semi-closed games beginning 1.d4 d5, covering the Queen's Gambit, Slav, Grünfeld and related queen-pawn structures. This particular variation is reached
after 12 half-moves from the
starting position, with the move sequence 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. e3 e6 5. Nbd2 Nbd7 6. Bd3 c5.
It belongs to the Queen's Gambit Declined family. Within that family this is a sub-variation (the Semmering Variation line).
The opening sequence in prose form: 1.d4 d5, 2.c4 c6, 3.Nf3 Nf6, 4.e3 e6, 5.Nbd2 Nbd7, 6.Bd3 c5. From this position the encyclopaedia records no further canonical continuations — practical play branches into unnamed transpositions or returns to the parent line for alternative ideas.