Chess Opening Theory/1. e4/1...e5/2. d4/2...exd4

Centre game C21 Centre game 2...exd4 Black takes White's d-pawn. Retake the pawn 3. Qxd4 is the main move. This allows Black to develop 3...Nc6 with tempo, forcing White to move their queen again. 3. Nf3, the Kieseritzky variation, allows White to prepare to retake the pawn with the knight instead. This avoids giving Black ...Nc6 with tempo. 3...Bb4+ or 3....Bc4 are playable, or there are several possible transpositions including 3...Nc6, transposing to the Scotch game, 3...d6 to the Philidor defence, and 3...Nf6 to the modern attack in the Russian game. Gambit the pawn 3. c3 is the Danish gambit. White offers to let Black keep the pawn in return for rapid development. They may gambit one (3...dxc3 4. Nxc3) or two (3...dxc3 4. Bc4 cxb2 5. Bxc2) pawns in this way. This is playable, and White gets a lot of piece activity in compensation for the pawn(s). 3. Bc4, the von der Lasa gambit, is also playable. An independent line follows 3...Bb4+, but usually this transposes into one of several different gambits. If 3...Nf6, White can transpose into the Urusov gambit with 4. Nf6 (4. e5?! and Black is better after 4...d5!). After 3...Nc6 instead, White may yet play c3 and transpose into the Göring gambit (4. c3 dxc3 5. Nf3, with the idea 5...cxb2 6. Bxb2), or otherwise transpose into the Scotch (4. Nf3 Nf6, where the choice is 5. e5 or gambit the e-pawn as well with 5. O-O). 3. f4? is the Halasz-McDonnell gambit. Having deflected Black's pawn away from control of f4, White seizes space on the king's side. This gives Black time to defend their pawn, 3...Nc6, and they can gain initiative attacking e4, 4. Nf3 d5!, because White cannot defend it with Nc3 until they have removed Black's d4-pawn. Against best play White is not thought to have compensation for the pawn. 3. Bd3 is the Ross gambit. This is a less ambitious square for the bishop. Black can defend the pawn with 4. Nc6 and White has partial compensation. Theory table 1. e4 e5 2. d4 exd4   3 4 Evaluation Notes Center Game Qxd4 Nc6 Qe3 Nf6 = Danish Gambit c3 dxc3 Bc4 Nf6 = Scotch Game Nf3 Nc6 Nxd4 Bc5 = Petrov's Defence Nf3 Nf6 e5   Steinitz variation of Petrov's. More commonly: 1. e4 e5 2. Nf3 Nf6 3. d4 exd4 von der Lasa Gambit Bc4 Nf6 Qxd4 Bb4+ = Urusov Gambit Bc4 Nf6 Nf3 Nxe4 = Halasz Gambit f4   References External links 365Chess: 1. e4 e5 2. d4 exd4 Center Game