Quote Originally Posted by Yuki_Akuma View Post
Why would they need to research it? The BBEG probably kept notes.
On the list of things to never do as a super villain, keeping detailed notes of your evil plans is right up there with "Though shalt not have hero sized heating ducts"

Personally, I always resolve to never guarantee the death of a player. There is always a way out. Finding it, however, may vary in difficulty. I will also never deny something that a player has worked towards out of hand. That said, I have players warn me at least 3 levels in advance of any multi-classing / prestige classing and they have to clear feats with me in advance.