A new 4-digit lock every day. Three clues narrow it down. You get five tests to crack it.
Roll the wheels to a code (drag them, tap above or below the slot, or tap a digit on the strip) and press TEST. Each wheel lights up:
Tests stack upward from the lock. Digits you have ruled out grey themselves on the strip. A digit can repeat, unless a clue says otherwise.
Reading the clues. Every clue is true and every clue matters, but they rarely name the code outright. Think like a logic puzzle: "If there is a 3, then there is no 7" also means a 7 rules out the 3, and says nothing at all when there is no 3. "Either the 4 or the 9, but not both" is two cases. Clues chain: one fact from a test can set off two more.
The clues leave a couple of dozen possible codes. Your first test is a bet. The colours then decide which clues fire next. Most locks fall on test three.