Read the coupling.
Three rings. Three controls. Every turn has a partner.
Start with the marks
The outer, middle and inner rings each show a position from 0 to 7. Zero is the top alignment. Your task is to bring all three rings to zero at the same time.
A new lock is produced by a sequence of legal turns from the aligned position, so its starting state is reachable. It does not require guessing an invisible rule.
Use the right pair
- Outer + middle advances those two rings by one stop.
- Middle + inner leaves the outside ring alone.
- Inner + outer keeps the middle ring in place.
All turns are clockwise. One stop is 45 degrees; advancing from position 7 returns a ring to 0. Each press counts as one move.
Ask for a route, not a free turn
The hint searches the reachable states and tells you which control begins a shortest remaining route. It also reports how many turns that route needs. The board does not move until you choose a control yourself.
Hints are available without payment or limits. Asking for one does not add a move to the counter.
Reverse, repeat, replace
Undo takes back one turn, including a turn that finished the lock. Reset restores this puzzle's original positions. New lock chooses another reachable arrangement and clears its history.
Once all three marks align, the turn controls pause. You can undo to examine your last step or request a new lock.
A useful piece of arithmetic
Show why the paired controls matter
If the three controls are pressed a, b and c times, the ring advances are a+c, a+b and b+c. Read each total modulo 8. A correct route makes the starting positions plus those advances equal to zero.
Keyboard operation
Tab moves among the three turn buttons and the helper controls. Activate the focused button with Enter or Space. The status text announces hints and completion without requiring you to interpret colour alone.