Parmandur
Book-Friend, he/him
Yes, DM fiat is centrsl to how D&D works. The tule is that the DM uses fiat to determine if a check is warranted, and gating behind proficiency is one of the main ways this is done. Simple, common sense gating in fact eliminates any problem that is being theorycrafted in this thread, and yeah, DM fiat is how it works. That's how all of this works.But proficiency is just another made up reason for DM fiat in denying a check when there isn’t a mechanical reason to deny it If 20 succeeds