So this probably sounds like a newbie question, but I am having a hard time wrapping my head around this. For example, can a Druid with no ranks in Knowledge (nature) not even attempt that skill check? That sounds really, really stupid, considering it is a class skill for them, but my friend/DM says thats right. Reading the passage about Untrained Skills makes me think that is wrong. It's on their class skill list, and even if they have no ranks in it, their general knowledge (Int mod) should still allow them to make the check, just like if you have no ranks in Climb, you can still use you Str mod to make the check. It just wouldn't be as good.