Key ideas
- The main gambit runs 2...dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3. White is a pawn down but has a lead in development, the half-open f-file and attacking chances with Bd3, O-O, Ne5 and Qe1-h4.
- Black's main defences after 5.Nxf3 are named: 5...Bg4 (Teichmann), 5...e6 (Euwe), 5...g6 (Bogoljubov), 5...c6 (Ziegler) and 5...Bf5 (Gunderam).
- Black can also sidestep the main gambit. 3...e5, the Lemberger Countergambit, strikes back in the centre and can lead to an early queen trade after 4.dxe5 Qxd1+ 5.Kxd1, while 3...Bf5 (the Zeller Defense) develops the bishop before White plays f3.
Plans for White
Develop fast with Nc3, Nf3, Bd3 or Bc4 and castle, then aim the f-file, the bishops and a knight on e5 at f7 and the black king. Slow play lets Black consolidate the extra pawn.
Plans for Black
Accept the pawn, develop quickly and return material if it breaks the attack. Plans with ...e6, ...c5 or ...c6 and ...Bf5 or ...Bg4 trade off attackers and free the position.