Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...Nf6/6. Nxf6/6...Qxf6/7. Qe2

Attempting to defend the e-pawn with moves like 7...d6 or 7...Bd6 are ultimately futile. Either 7...d6 8.d4 or 7...Bd6 8.d4 (not allowing Black the trick 8.Bxc6 dxc6 9.d4 Bg4) just win it outright.

So instead Black gambits the pawn with 7...Be7. The compensation will be in the form of open lines for the rooks and an unopposed light-squared bishop.