I have some concerns brought to me by a player and they are pretty valid. With the catch of cold iron covering all iron and steel weapons almost every Tom, Dick and Harry will have access to cold iron or steel. I know I was going to make sure to take modern materials into consideration. Between high carbon steels, titanium coated or titanium blades, plastics and polymers, and even aluminums or other alternative metals I think that barring an npc specifically going after a character with cold iron intentionally I was going to kinda make a random check to see if any specific weapon used would meet the catch, so that not every knife in the world will bypass his character's defenses. Does anyone have any suggestions on how they might handle this in the game?