King's Gambit Accepted, Cunningham Defense

The Cunningham Defense begins with 1.e4 e5 2.f4 exf4 3.Nf3 Be7. Black has accepted the offered pawn and develops the f8-bishop to e7. The move looks quiet, but it has a concrete point: from e7 the bishop may travel to h4 and give check along the h4-e1 diagonal if the intervening squares remain clear.

After a natural developing move such as 4.Bc4, Black may consider 4...Bh4+. A check forces the opponent to remove the attack, block it, or move the king. If White’s king must leave e1, White normally loses the right to castle, the special move that moves the king and a rook to improve king safety. Black is therefore trying to develop with a threat that forces White to respond.

White is not required to allow the idea without preparation. A different move order may defend the diagonal, or White may accept the check and seek activity in return. Black should not play ...Bh4+ automatically either: if the bishop becomes exposed or the check helps White’s king find a stable square, the maneuver may lose its value.

Difference from other accepted defenses

The Fischer Defense uses 3...d6 to control e5 and prepare a stable structure. The Cunningham develops the bishop immediately and draws much of its identity from the tactical possibility of ...Bh4+.