Lockpicking Minigame

Here is a random lockpicking minigame idea I had:

Lockpicking is guessing.  Each lock has a number from 1 to 10.  Without any skill you have a 1-in-10 chance of picking the lock.  For every point in dexterity you may roll D10 and determine if the lock's number is greater than, less than, or equal to the roll.  Those trained in lock-picking may manipulate their rolls by up to 3 in either direction.  After making all rolls the guess must be made.  If the guess is incorrect the lockpick is broken.  If the guess is off by 4 or more the lock is jammed.   

Lesser locks have more than 1 consecutive number.