This is for an RPG I'm working on.
There is a 15 card deck. The deck has 5 cards of 3 different glyphs.
The DM shuffles it and draw randomly 5 cards.
The player has to guess, in the order they were drawn, which glyph is there.
If the player guesses all of them right, the lock is picked.
There are 3 retries, meaning you can guess again.
There is always a key somewhere laying around, meaning every lock can be opened.
The odds of succeding the lock pick is 31/81 around 38%.
Is it okay?
If there is no strategy involved, and a person just has a blind % change to succeed, don't bother doing it with cards. Roll a dice have something like a 1 or 2 mean success.
A. I like the tension because a look can only be tried tob opened once, unless some skills or items.
B. As in A, ther is a room for skills and items to come in.
You do have a point it might be annoying, but I wanted to give an option by chance to skip looking for the key.
Any idea that involves skill directly?
I'd probably include a "you hear a click" mechanic. When the player guesses right, the card is placed face up on the table and he moves on to the next one in sequence.
I'd also only use 9 cards, so that the next card may be guessed at by using a meaningful probability of which ones remain.
I think the act of lock picking is not interesting enough to warrant all the fuss. If you force a player to micromanage everything in a game, things will quickly become unwieldy and unfun. What's next? A deck to convey horse-riding skill, or a deck to test if they ate a healthy meal? If you want lock-picking in the game at all, you need to make it really simple. Either that, or make it a game really focused around lock-picking (which I think would be really hard to pull off well).
Perhaps you could change the use of the cards such that each time a player attempts a certain type of action (pick lock, disarm trap, sneak, etc.) and fail, they get a card at random from the deck. At any time they can trade in 2 of the same symbol card to pass one of those actions, or trade in a set of 3 to "critically" pass the action. Of course, only could only get a maximum of one card per actual lock encountered. Can't have the players repeatedly failing on a single lock just to get all the cards at once. :P
Not sure how you would justify it in game though...
This mechanic is inspired by Deus Ex: Human Revolution. I didn't know there will be much hate towards it. But again, like in that game, every lock has a password somewhere near by. That mechanic meant to be a "Test of Luck" for trying to unlock it. I'm keeping it as a little fun. A campaign can exist entirly without locks.
I like dan55's suggestion. that actually has elements of skill and deductive thinking. Maybe that could only be available if you are trained in lockpicking.