Chess Opening Theory/1. e4/1...e5/2. f4/2...exf4

If Black could make a free move in this position, it would undoubtedly be ...Qh4+. White couldn't successfully block the check with the g-pawn thanks to the Black pawn on f4, and the awkward move Ke2 would be forced.

How should White deal with the threat? There are two main approaches, 3. Nf3 and 3. Bc4.

3. Nf3 is the most obvious approach: control the h4 square and develop a piece to its most active square. This is called the king's knight gambit. Now, White at last threatens to play d4, taking over the centre and discovering an attack on f4 to recover the pawn, and Black has a wide range of ways to play.

3. Bc4, is the bishop's gambit. This develops the bishop to an active square and gives White's king another square to move to, preparing to answer 3...Qh4+ with 4. Kf1, and then to gain tempo on the queen with Nf3. More common are 3...Nf6 and 3...d5.

Unusual approaches (that you probably should not play) include:

• 3. Qg4?, the Dodo variation, is an eccentric also-ran where White's queen guards h4 directly while threatening to take on f4. If Black gives the pawn back they should have an easy time, exploiting White's queen for tempi.
• 3. h4, the Stamma variation, controls h4 with the rook so disallowing ...Qh4+. It is, however, another pawn move, giving Black the time to get ahead in development and perhaps deny White the chance to play d4 at all, which was the whole point of the exercise. 3...Nf6 4. Nc3 Nc6 5. Nf3 Bb4∓.

Lots of other third moves for White have been tried but are not good.

Those that allow 3...Qh4+ include 3. d4?!, the Villemsom gambit, and 3. Nc3?, the Mason-Keres gambit, but 3...Qh4+ 4. Ke2 leaves White's king too weak.

There are a couple of other ideas to allow ...Qh4+ but remove its sting:

3. Qf3?!, the Breyer gambit, has the interesting plan to allow 3...Qh4+ but answer it 4. g3, as now after 4...fxg3 5. hxg3! and queen defends both the pawn and the rook.

3. Ng3?!, the Eisenberg variation, is cute, intending 3...Qh4+ 4. Nf2.

1.e4 e5 2.f4 exf4

Wikipedia has related information at King's Gambit.

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

• 365Chess. 1. e4 e5 2. f4
• chessgames. 1. e4 e5 2. f4