Quote Originally Posted by dgnslyr View Post
Not quite sure on the RAW, but a natural 20 is an auto-hit, regardless of AC, and Wall of Blades just gives you an alternative way to calculate AC, I'd say a natural 20 still hits, no matter what.
Cutting across the issue here, but I'd thought concealment chance cuts across natural 20, doesn't it? If not, there's probably a few disgruntled players I need to talk to...