First of all: imho a good GM will not let a player make a skill check, or any roll for that matter, that they cannot succeed on. That is just unnecessary and even very frustrating for the player. Unless the GM is just a huge douchebag who intends to piss their players off they should never do that. Imagine you are the player and you are told you failed while you rolled your maximum possible with a 20 on the dice. Bleh. Why would I ever play under that GM again.
Secondly there is good reason in game design sense for the critical failure/success rule on a nat 1 or nat 20 respectively only applying to attack rolls. It should never be used for anything else if you don't intend to tamper with the games balancing as a whole and possibly make the game unnecessarily hard and less fun on your players. Someone who is super versed at something will be able to recall basic knowledge on a subject even if they're having one of their worst of days (rolling a nat 1). If they still manage to score over certain thresholds then they just do that. A 5 is easy knowledge which shouldn't even require a roll as the DMG suggests, as most proficient chars will score above it anyway even on a nat 1.
Frankly in your example, which is something not unheard of, the Barbarian outscoring the Wizard at Arcane Knowledge is a matter that somewhat needs addressing nontheless imho. But letting them roll while having made up your mind on letting them fail at it no matter what is not the way to go. Maybe one could homebrew a secondary table for unproficient characters. One would have to playtest a certain ruling but for example one could rule that unproficient characters have at least one step lower knowledge on the table so when you normally would have to score above 10 as a proficient character and unproficient one would have to score above 15 for that knowledge for example. Not only harder to do because they lack the bonus from proficiency but also less detailed knowledge behind the success as all they got is hearsay and other vague sources as opposed to someone who knows it from reliable sources like a book or a mentor.
Last edited by Obsidian Gold; 31/10/21 12:40 AM.
