The Blackburne Shilling Trap is a gambit that many black players like to try in the common Italian game from white. Instead of playing the normal Giuoco Piano or even the Ruy Lopez, black offers up a pawn sacrifice on e5.
1. e4 e5
2. Nf3 Nc6
3. Bc4 Nd4
White should decline the offer to go up in material or else he will find himself actually down in material. Depending on how poorly white plays after falling for the trap will determine just how much material he will lose.
The best thing white should do is castle king side and continue his development. Black has moved his knight twice, which does nothing for this development and white can now be up 2 moves in development while black is wondering what to do now that white did not fall for the trap.
If white does fall for the trap though, black will immediately bring his queen to g5 and attack not only the knight on e5 but also the g2 pawn, and a now exposed white king.
Watch the video below to see a detailed explanation of the trap.