Has anyone done something like this before?

[Ferrus]

A few nights ago I was DMing my first adventure and had an idea for a treasure trap.

Bare in mind that I've never really ran a game and only played the starter set game.

Basically it was a small box hidden behind a false brick that was uncovered on a natural 20. The treasure was just going to be a couple of smoke sticks but creativity got the better of my and i told the PC that there was a small silver looking box with an intricate looking lock on it. After the first attempt to pick it failed they heard a soft click and nothing else happened, the second try was another natural 20 so obviously it opened.

Revealing a small jar of acid conected to a few small gears that would click down every time the lock was interfered with and didn't open. The end result would have been a jet of acid coming from the keyhole of the lock.

I was wondering if someone had come across something like this before?

Ta.

[Kol Korran]

so it's a "try X times or trap happens" sort of trap? hhmmmm... no, i haven't tried it, but it sound like an interesting idea. just make the threat viable (5 times to try wouldn't be good), and have s reason for it to be this way (why would you want to give thieves further attempts?)

i like the idea though, and welcome to DMing!

[KillianHawkeye]

Natural 20s aren't an automatic success on skill checks. /themoreyouknow

[Ferrus]

Natural 20s aren't an automatic success on skill checks. /themoreyouknow

Oops, ah well now I know..... sod it "And knowing is half the battle"

[Malimar]

just make the threat viable (5 times to try wouldn't be good), and have s reason for it to be this way (why would you want to give thieves further attempts?)

I think the standard bank gives you three or five attempts to log in to your online account before locking you out until you jump through some hoops, in case you didn't notice your capslock is on while entering your password or something. Maybe the mage doesn't always notice when the capslock on his key is on? Wait, no, that makes no sense.

Okay, maybe the mage wants to make sure he can still get in if his key gets wrinkled in his pocket and it takes a couple attempts before it scans properly. Except locks aren't vending machine cash slots, so that's still not a perfect example.

[Ferrus]

Ever tried opening a mortice lock after a few drinks? When you have a ring of keys?