There's a handful of doors I know that take a DC30 to lockpick.
But, you know. Get your high dex character with sleitgh of hand proficiency [expertise], guidance, cat's grace, Bardic Inspiration and presto. Maybe roll twice. Failing all that..... KNOCK. But those instances are stupidly rare. I'm actually surprised there are *so* many DC10 locks everywhere that your 10Dex Cleric can lockpick. What's the point of having a thief these days? Or rather, why do people in this world bother with locking things?
Now, certain dialogue choices are high, for sure - convincing that Red Dude to join your team instead of his boss' team. But that *should* be hard and only possible if you're the smoothest talker since Christopher HItchens. Then again, these DC's are at the very end of the game, too - where you have sufficient means to boost your abilities.
And, there is of course a handful of the 99 rolls. Those can only be succeeded on a nat 20; but that too is by design. You know, 'resist the big bad' or 'lockpick the most secure vault door on the Sword Coast'
