Norwegian Defense, Norwegian Gambit

With 4...d6 Black abandons the h5-knight and attacks the e5-pawn. Almost all games continue 5. Bxh5 gxh5 6. Qxh5, after which 6...dxe5 restores central tension and gives Black practical chances built on traps rather than material. White can also decline with 5. exd6 Qxd6 6. Nf3 and develop normally. Engines rate White clearly better, yet Black scores heavily in online games. Magnus Carlsen played it against Michael Adams at the 2010 Olympiad.