The Complete Rules
how to playYou are given a cluster of hexagons and a pool of numbers. Place one number in every hexagon so that no connection between two hexagons breaks a rule. When every hexagon is filled and not a single connection is broken, the puzzle is solved.
Shestoku takes its name from shest — “six” — and the -ku of sudoku: a number puzzle built on the six sides of a hexagon.
01 The pieces
Hexagons
The board is a cluster of hexagons. Each one holds exactly one number, and every hexagon must be filled for the puzzle to count as complete. The number in the top-right corner tells you how many hexagons there are to fill — the size of the challenge in front of you, and the count of numbers you will place.
The number pool
Beside the board is a pool of numbers — exactly as many numbers as there are hexagons. Each number is used once and only once. When the board is full, every number from the pool has been placed and no number repeats.
The pool is optional. It is hidden by default and can be revealed with a button whenever you want it. Shown, it is a handy reference and lets you drag numbers onto the board. Hidden, you simply type the numbers in — useful if you would rather solve without the list in front of you.
02 Connections
Two hexagons are connected in either of two ways:
- Touching — they share an edge, sitting directly against each other.
- Connector lines — a drawn line joins two hexagons that may not be touching.
Both kinds of connection count equally. If two hexagons are connected — whether by touching or by a line — the rules apply between them. If they are not connected, nothing restricts them, even if they sit near each other on the board.
03 The two rules
Two connected hexagons may never hold numbers that break either of these:
No consecutive numbers
Connected hexagons cannot hold numbers that sit next to each other on the number line.
No shared digits
Connected hexagons cannot hold numbers that share any digit.
A connection is legal only if it passes both rules. The numbers must be non-consecutive and share no digit.
04 Legal or not?
| Connected pair | Allowed? | Why |
|---|---|---|
| 7 and 8 | ✕ No | Consecutive on the number line |
| 31 and 13 | ✕ No | Share the digits 1 and 3 |
| 5 and 57 | ✕ No | Both contain a 5 |
| 7 and 20 | ✓ Yes | Not consecutive, no shared digit |
| 48 and 13 | ✓ Yes | Not consecutive, no shared digit |
05 How to play, step by step
06 A note on solving
Because feedback only arrives when the board is full, the challenge is to reason ahead rather than guess and check. Start with the most connected hexagons — the ones with the most neighbors are the hardest to satisfy, so settling them early narrows everything else. Every puzzle you are given has at least one valid solution; it was verified solvable before it ever reached you.
07 Common questions
What is Shestoku?
Shestoku is a hexagon number-placement logic puzzle. You fill a honeycomb of hexagons with numbers so that no two connected hexagons break a rule. Its name comes from shest (“six,” for the six sides of a hexagon) and the -ku of sudoku.
How do you play Shestoku?
Click a hexagon and type a number, or drag one from the pool. Two connected hexagons — touching, or joined by a connector line — can never hold consecutive numbers or numbers that share a digit. Fill every hexagon without breaking a connection to win.
Is Shestoku like Sudoku?
It shares Sudoku’s spirit of placing numbers under constraints, but the board is a hexagon honeycomb and the rules are different: no consecutive neighbors and no shared digits between connected hexes, rather than row, column, and box uniqueness.
Is Shestoku free to play?
Yes. You can browse, generate, and play unlimited Shestoku puzzles for free. An optional free account saves the puzzles you have solved to your profile.
Can I make my own Shestoku puzzles?
Yes. Use the built-in editor to design a board, solve it, and publish it. Every published puzzle is verified solvable before it appears, so players are never handed an impossible board.
Every puzzle is solvable. The only question is whether you can find the way.