Chess Opening Theory/1. e4/1...e5/2. f4/2...exf4/3. d4

=Villemson Gambit=

3. d4
Just like the Queen’s gambit, this move reveals an attack on the f4 pawn. However, the Villemson Gambit can cause black to wreck havoc with Qh4+. White is forced to play Ke2 because if white plays g3?? black can respond fxg3 and the h2 pawn is pinned.

Theory table
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'''1.e4 e5 2.f4 exf4 3. d4'''