Lockpicking with GAMBLING and MATH

Lockpicking in RPGs has always bothered me for reasons many have expressed before, so I made my own system, based on Errant's/Telecanter's.

The System

You need a pick and a few moments to pick a lock. The referee rolls at least three d4 in secret, more if the lock is complicated. The referee then tells how many dice were rolled and the sum of the faces, but keeps the dice themselves hidden.

The lockpicker guesses how many of the dice share a face. They don't guess the face itself, just the number of dice sharing one. In combat, each guess requires one action/turn/etc. If the guess is correct, the referee reveals a corresponding set of dice sharing the same face. If multiple corresponding sets are available, like two 2s and two 4s, the referee reveals only the one with the smallest shared face. After revealing the set, the referee announces the sum of the remaining dice. The lock is picked when all dice are revealed.

First wrong guess stiffens the lock, second jams it and makes picking impossible. A worn lock ignores the first wrong guess. A secured lock jams on the first wrong guess. A trapped lock triggers on a wrong guess, depending on the trap.