I thought the DC99 was funny, and did have a couple of goes just to see if I’d manage to score a critical success as I thought lockpicking the secure vault would be a cool thing to have on my sorceror/rogue PC’s CV. Disappointing to hear this wouldn’t have worked anyway! I didn’t roll an 20 in any case, so just went ahead and followed the hints lying around about what to do instead. I’m assuming that there are other ways to succeed, as no NPC was involved in my solution.
For high Dex characters with sleight of hand proficiency or ideally expertise, plus boosts, DCs of 25 and 30 are fairly easy to obtain, though I have occasionally worked my way through a few lockpicks with series of not-so-good rolls. Though for tough locks that feels right to me. And there can be other ways to get into locked chests and doors.
