Chess Opening Theory/1. e4/1...c6/2. d4/2...d5/3. Nc3/3...dxe4/4. Nxe4/4...Nd7/5. Qe2/5...Ngf6

5.Ngf6??
This move looks like simple development, yet black is now doomed to a mate in 1. Can you see it?. This trap has ensnared countless amateurs. Much better is 5...Ndf6.