Moves 0
Fewest possible 0
Best –
How to play
Goal
Take every ring off the bar. They all start on it.
The two rules
- Ring 1, on the far right, can always be put on or taken off.
- Any other ring can move only when the ring just to its right is on the bar and every ring further right is off.
How it works
- Tap a ring to take it off or put it back on. Rings that can move right now glow peach.
- So at any moment there are at most two moves: ring 1, or the one ring the second rule allows.
- Sometimes you must put rings back on to get others off. That's the trick of the puzzle.
- Choose 3 to 7 rings. The fewest moves grow fast: 5 for 3 rings, 85 for 7.
Tips
- Never make the same move twice in a row: it just undoes itself. Alternate between ring 1 and the other possible move.
- With an odd number of rings, start by taking off ring 1. With an even number, start with ring 2.
- The pattern of rings on and off counts in a special binary code, called Gray code, where each step changes just one ring.
The history of Chinese Rings
Known in China as jiulianhuan (“nine linked rings”), the puzzle has been played there for centuries and was described in Europe by Gerolamo Cardano in 1550. In France it is called the baguenaudier. Its solution was one of the first known uses of the binary Gray code.