|Moves||1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Nxe5|
|Parent||Four Knights Game|
The Halloween Gambit, also known as the Müller-Schulze Gambit or Leipzig Gambit, is an aggressive gambit in chess, in which White sacrifices a knight for just one pawn. It is a branch of the normally staid Four Knights Game. The theoretician Oskar Cordel reported in 1888 that Leipzig club players used it to dangerous effect but he did not believe it was sound. Their name for it, Gambit Müller und Schulze, was not after any players by those names; rather, it is a jocular German equivalent of "Smith and Jones" or "Tom, Dick and Harry". The opening is characterized by the moves
The goal of the gambit is to seize the center with pawns and drive back Black's knights. After 4...Nxe5, White usually plays 5.d4, in preference to 5.f4, which does not facilitate his development.
After 5.d4 the black knight can retreat to g6 or c6. If 5...Ng6, White chases the knight on f6 with 6.e5. After 6...Ng8 7.Bc4,
recommended 7...d5 8.Bxd5 c6. Fritz 8 plays this line, and after 9.Bb3 plays 9...Be6 10.Bxe6 fxe6 11.Qg4 N8e7 12.Bg5 h5, and now 13.Qxe6 Qxd4 or 13.Qe4 Qb6 14.0-0-0 Nf5 15.h3 Be7 16.Be3 0-0-0 17.g4 Nxe3 18.fxe3 Nh4.
If 5...Nc6, White plays 6.d5, and if 6...Ne5, 7.f4. After 7...Ng6, the game usually continues 8.e5 Ng8 9.d6, completing the most commonly seen sequence in this opening. In the final position White is on the attack and will generally continue that with tactics such as Nb5 after a pawn trade at d6. However, Black can return the piece with a slightly better endgame after making White over-extend his pawns by 5... Nc6 6.d5 Ne5 7.f4 Neg4 8.e5 Bc5 9.exf6 Nxf6 and now White's best is heading for an uninspiring endgame by 10.Qe2+ Qe7 11.Qxe7 Kxe7.
A similar gambit can be used by Black: after 4.g3, Black can play 4...Nxe4!? This line is arguably sounder than its White counterpart because 4.g3 weakened the f3 square. Moreover, White cannot play the line recommended by Kaufman with colors reversed because 5.Nxe4 d5 6.Nc3 d4 7.Bb5? dxc3 8.Nxe5? Qd5 9.Qe2? loses to 9...Qxh1+. However, with the pawn on g3, Nh4 is possible and it should be easier to castle.