The King's Gambit is the opening that begins with the moves 1. e4 e5 2. f4, an aggressive sacrifice less popular today than in chess' romantic attacking era.

The King's Gambit runs as follows:

 [FEN ""]

 1. e4   e5
 2. f4  ...

This opening is much less popular today than it was in the attack-happy Romantic era of chess, but it still appears occasionally at the highest levels of the game. Hikaru Nakamura, for example, who is in the world's top 10 as of this writing, sometimes plays the King's Gambit against elite players, e.g. Nakamura-Adams (2011).

After Black accepts the gambit, White has two main possibilities:

  1. Nf3 or 3. Bc4

The first option leaves the knight possible to be kicked with g7-g5-g4. Black may also have the possibility to gain active pieces with 3...d5.

The second option allows Black to give a queen check on h4. However, the queen can then be attacked by the g1-f3 knight, and White can gain a big center.

Black can also decline the gambit, resulting in more positional games. The main line is 2...Bc5, stopping White from castling kingside. White usually plays Nc3-a4xc5, capturing the bishop, and then castling.