jmartkdr2
Hero
I mean, if it’s not ridiculous than a 5% chance should be reasonable. It’s not like people can really feel the difference between that and 3%.Player: <declares borderline-impossible but not ridiculous action>
DM: "Sorry, you fail the attempt."
Player: "I don't get a roll? A 20 always succeeds - it says so right here - and <presents in-fiction case where a lucky roll could succeed>"
DM: "Sorry, no roll."
<argument erupts, and so much for that session>
That exchange will happen at thousands more tables than it would have without this rule. Just watch and wait for it.
And it's so very avoidable, simply by making it that 1s and 20s succeed more often than they should but its still not guranteed.
That said, I'm all for 1s and 20s being automatic on saves and to-hits. It's just the ability check (or "test", now) business where it breaks down, and even then only in some situations.
If even 5% is way too high, then tell the player it’s beyond them (under current circumstances). I don’t think any reasonable-ish dm will just day “you fail” and not elaborate - that’s what would cause arguments rather than a sudden jump in player entitlement.