King's Gambit Declined: Norwalde Variation, Bücker Gambit

The King's Gambit Declined: Norwalde Variation, Bücker Gambit is a chess opening classified under ECO code C30 in the Open Games & French Defense family, beginning with 1.e4 e5 or 1.e4 e6, including the Italian Game, Ruy Lopez, and French Defense. It is reached after 5 moves: 1. e4 e5 2. f4 Qf6 3. Nc3 Qxf4 4. Nf3 Bb4 5. Bc4. The resulting position leaves black to move.