Of course there are some old classic rules, but I put a twist on them. For example a common modern werewolf killer is silver. Well, in my rules system I wrote that silver indeed gives its wielder an advantage over the werewolf, but it's not necessarily a 100% death probability. All silver-based weapons do in my world is greatly increase the chance of inflicting serious bodily injury or death to a werewolf. A simple strike to a werewolf's head with a silver-tipped cane will definitely do some damage, but if its user is really small compared to the werewolf maybe the result won't be death.
Conversely silver is not the only way to kill a Frank Bruce werewolf. Fire and acid would be obvious means of inflicting death, but also catastrophic damage from any old weapon dispensed in a short amount of time could do the trick too. For example shooting a werewolf with a machine gun (with lots of head and torso shots) could work.
In fact when you look at my werewolves, you'll see they don't possess obnoxious super-human strength. They have very human limitations. Several of my werewolves even get punched or damaged when engaged in combat, such as is true in the real world when lions or wolves go on the hunt. There is always a risk of death. Werewolves that are too strong make for boring monsters.
Remember the the 2010 film The Wolfman starrring Guillermo del Torro? The opening sequence portrayed the beast as running so fast as to be invisible. You know what? That sucked. Speed does not scary make. I'm way more into an American Werewolf in London beast hurrying through Picadilly Circus. It's not very fast and could easily have been killed by a car. I like werewolves with some human limitations. They are, after all, partly human.
So I guess I'll soon start posting, one by one, my Frank Bruce rules that govern the werewolves in my world. Do you have any ideas?