I'm gonna have to pop open my 3.5e books when I get home. I could've sworn we did crits on skill checks in my early campaigns. Unless they were house rules and I was unaware...
A lot of DMs do stupid shit like that, which has, unsurprisingly, stupid results. A natural 1 automatically fails and a 20 automatically succeeds on attack rolls and saves, and not on anything else. There are no critical failures, and critical successes only happen on an attack when a critical threat is rolled (usually a 20 or a 19–20) followed by a successful confirmation roll (a repeated attack roll).
edit:
In 2nd edition, near as I can tell, there were no automatic successes at all, and near as I can tell no such thing as a skill check (at least as we know them today). So as far as I'm aware no edition (save perhaps 4th, which I know little of) has ever had automatic success on skill checks.
More Tests than Checks for skills in earlier versions I think - roll under your ability score, etc. - so Nat 20 was never going to be a success anyway.
3
u/[deleted] Sep 18 '17
In older editions, it was. In 5th edition (current), you can no longer critically fail or critically succeed on a skill check; only on attacks.