Blackburne-shilling gambit 1.E4 e5 2.Nf3 Nc6 3.Bc4 Nd4?!
The point being that if white is greedy, black wins material with 5.Nxe5? Qg5!
Of course, if white doesn't take the poisoned pawn and just castles, black has just played a premature ...Nd4 and will probably be worse, but you can't have everything
Nd4 works once and never again
An example of how powerful the Steiner is for the unaware.
(he's suppsed to play Re3, but humans aren't computers)
A normal human continuation from White would be:
Blackburne-shilling gambit 1.E4 e5 2.Nf3 Nc6 3.Bc4 Nd4?!
The point being that if white is greedy, black wins material with 5.Nxe5? Qg5!
Of course, if white doesn't take the poisoned pawn and just castles, black has just played a premature ...Nd4 and will probably be worse, but you can't have everything
Nd4 works once and never again