Chess Opening Theory/1. d4/1...d5/2. e4/2...dxe4/3. Nc3/3...e5

Blackmar-Diemer Gambit (BDG)
a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h
Position in Forsyth-Edwards Notation (FEN) rnbqkbnr/ppp2ppp/8/4p3/3Pp3/2N5/PPP2PPP/R1BQKBNR w
Moves: 1. d4 d5 2. e4 dxe4 3. Nc3 e5

Blackmar-Diemer Gambit (BDG): Lemberger Countergambit

3... e5

Black has advanced their pawn to e5 and offers a pawn transfer. If White takes the e5 pawn, then Qxd4 forces White to either give up the right to castle with Kxd1 or undevelop the knight with Nxd1. However, there are better options such as Nxe4, encouraging Black to take d4 with the queen and make a queen trade, or Nge2, declining the countergambit and protecting the d4 pawn.

Traps

The Sneiders attack with Qh5 can lead to a winning position on the 6th move with Nd5?!, with most opponents going Qd7? and blundering Qe5+! and Nxc7!. However, there are players who refute this with a counterattack of their own with Nf6, leading to a queen exchange with both knights capturing the opposing queens.

Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation..

1. d4 d5 2. e4 dxe4 3. Nc3 e5

	4	5	6	7	8
Lange Gambit	Nxe4 Qxd4	Qxd4 exd4	Bf4 Bf5	Bd3 Bxe4	Bxe4 c6	⩲
Endgame Variation	dxe5 Qxd1+	Nxd1 Nc6	Bf4 Bf5	Nc3 O-O-O	Bb5 Nd4	=
Sneiders Attack	Qh5 exd4	Bc4 Qe7	Nd5?! Qd7?	Qe5+! Ne7??	Nxc7+! Kd8	+ −
	... ...	... ...	... Nf6	Nxe7 Nxh5	Nxc8 Nc6	⩲

References

• Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.