Step 1 : Introduction to the question "According to legend, what is the only way to kill a werewolf?"
...Stories about killing werewolves with silver bullets are set in the folklore of America. But the method for doing away with these troublesome beasts doesn't come from mythology or folklore. The idea came from the movies. In the 1941 film "The Wolf Man," writer Curt Siodmak came up with the idea that silver bullets are Kryptonite to werewolves. It was also his idea to have the werewolf transform into his lupine form in the light of the full moon. Siodmak did admit to being influenced by superstition and folklore when writing his classic script. Source: Werewolves.com
