JW Carroll's page

Even if the untrained proficiency modifer is level-2 it still makes little sense. By that logic a high level rogue who has trained their Stealth all the way up to legenday is only 25% better at stealth than a character who has never trained in it at all. While I like the idea of a charavter's overall level improving their skill even when they haven't trained, I think the RAW is an invitation to inflated DCs and it makes skill based PCs like rogues and bards largely redundant. Better in my view to make the untrained proficiency bonus level/2

Forgive me if this has been covered already but based on my reading of the RAW the proficiency modifier for untrained traits makes very little sense.

From p 15 under Step 7 "...subtract the proficiency modifier (your level-2) from the relevant ability modifier..."

As written a level 1 character would use the following equation to determine their skill modifier with a relevant ability modifier of 0: 0-(1-2) or 0-(-1) or 1. This is the same modifier as a proficient character. Following through on this a 20th level character would have a skill modifier of 0-(20-2) or -18 making a 20th level character worse at an untrained action than he was at first level.

As this makes almost no sense (I suppose you could justify it as higher level characters being more hyper specialized) I have to assume that an untrained character is supposed to have a proficiency modifer of their level-2 instead of their level so a first level character has a proficiency modifier of -1 and a 20th of +18. This is logical but it seems to me that without some serious DC inflation you are going to have PCs of even moderate level that will be able to crush almost any skill challenge presented to them and that PCs that rely heavily on skills (namely rogues) are going to become largely redundant.

As a possible fix I'm considering for my own game adding level/2 as the proficiency modifier for untrained skills...though I'm waiting to see how much things like class features add as I read more of the rules.