Chess Opening Theory/1. f4/1...e5/2. fxe5/2...d6/3. exd6/3...Bxd6

3...Bxd6
This move develops with a threat. There are three sane ways to stop Qh4+. The first one, Nf3, is the best move. The second one, g3?!, runs into a rapid drill attack after 3...h5. A sample line: Nf3 h4! Nxh4? (gxh4 is better, but black has good compensation for the pawn after the simple 5...Bg4) Rxh4! gxh4 Qxh4# The third one, 4.h4??, runs into Bg3 mate! Also, one more trap is Nh3?? Bxh3 and Qh4 mate to follow.