The Blackburne Shilling Gambit is the name facetiously given to a dubious chess opening, derived from an offshoot of the Italian Game, that begins: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nd4?!
It is also sometimes referred to as the Kostić Gambit after the Serbian grandmaster Borislav Kostić, who played it in the early 20th century.
Black's third move is, objectively speaking, a weak, time-wasting move. Steinitz recommended 4.0-0 or 4.Nxd4 in response. International Master Jeremy Silman writes that White has an advantage after 4.0-0, 4.c3, or 4.Nc3. He recommends as best 4.Nxd4! exd4 5.c3 d5 6.exd5 Qe7+ 7.Kf1 +/=, when 5...Bc5? loses a pawn to 6.Bxf7+! Kxf7 7.Qh5+.
The only virtue of 3...Nd4 is that it sets a trap that has ensnared many players. After the natural 4.Nxe5!?, Black wins material with 4...Qg5! Now the obvious 5.Nxf7?? loses to 5...Qxg2 6.Rf1 Qxe4+ 7.Be2 Nf3#, a smothered mate. This trap is what gives the line its name: the great English master Joseph Henry Blackburne reputedly used it to win shillings from amateurs. However, Wall has questioned this, stating that there are no recorded games of Blackburne with the opening.
King's Pawn Game (incl. Blackburne Shilling Gambit, Hungarian Defence, Paris Defence, Italian Gambit, Légal Trap)