A hexagonal logic puzzle with one simple rule
Each hexagon sits on three axes. No number can appear twice on the same axis.
You do NOT need every number 1-N on each axis. ✓ You just can't have duplicates.
Every hexagon belongs to exactly three axes. Here they are:
The grid size determines what numbers you'll use: a 5×5 grid uses 1-5, a 7×7 grid uses 1-7, and so on. Each number can appear at most once on any axis.
Let's work through an example on a 5×5 grid. Look at the cell marked with "?" — what number can go there?
Starting with 1, 2, 3, 4, 5...
Let's clear up the most common confusions:
Non-consecutive numbers are perfectly fine! You don't need 1, 2, 3 in order.
Duplicate numbers on the same axis are not allowed. (Two 3s here!)
In a 5×5 grid, some diagonals have only 2 or 3 cells. These diagonals do not need to contain all numbers 1-5. A diagonal with just cells containing 2 and 5 is perfectly valid!
✓ Having just 2 and 5 is perfectly valid — no need for 1, 3, or 4.
When a cell can only contain one possible value (all others are blocked by the three axes), fill it in! This is the most common technique.
The blue cell can only be 4 — the 1 blocks horizontally, 3 blocks on ↘, and 2, 5 block on ↙!
When a number can only go in one cell within an axis—even if that cell has other candidates—that cell must contain that number.
On the yellow row, only the blue cell can have 5 — the other 5s block it everywhere else via columns and diagonals!
Turn on Auto Pencil to see all possible numbers for each cell. Look for cells with only one candidate—those are your next moves!
The 💡 Hint button can find these advanced patterns:
Naked Pairs: Two cells in an axis with the same two candidates. Other cells on that axis can't contain those values.
Hidden Pairs: Two values that only appear in two cells on an axis. Those cells can't contain any other values.
The clues force the green cells to only have {1,4} — so 1 and 4 can be removed from other yellow cells in that row!
Common Peer: If two cells on the same axis both have only candidates {X, Y}, then one must be X and the other must be Y. Any cell that can "see" both of them (shares an axis with both) cannot contain X or Y.
The clues force the green cells to only have {2,3}. The red cell sees both (via row and ↙ diagonal), so 2 and 3 are eliminated!
Naked Triples: Three cells sharing exactly three candidates. Those values can be eliminated elsewhere on the axis.
Hidden Triples: Three values confined to three cells. Other candidates in those cells can be eliminated.
X-Wing: When a candidate appears in exactly two cells on two different parallel axes, and those cells form a rectangle, the candidate can be eliminated from other cells on the perpendicular axes.
The clues force the blue cells to have subsets of {1,2,4}. So 1, 2, 4 are eliminated from other yellow cells on that row!
Automatically fills in all possible candidates for every empty cell. Updates in real-time as you solve.
Watch what happens when you place a 3:
The 3s on the same axes disappear, but corners keep theirs (different axes)!
Get help finding the next logical move. Works in two stages for learning.
Watch the two-stage hint process:
Hint finds the only possibility: "Naked Single: 3 is the only candidate!"
Highlights cells where the currently selected number cannot go based on existing placements.
The 3 blocks all cells on the same row, column (↘), and diagonal (↙).
Double-click any cell to highlight all instances of that number across the grid.
Double-click any 4 and all 4s across the grid light up yellow!
| Action | Mouse/Touch | Keyboard |
|---|---|---|
| Select cell | Click | Arrow keys |
| Enter number | Click number button | 1-9 |
| Pencil mark | Click small number button | Shift + number |
| Clear cell | Click ✕ | Backspace |
| Undo | Click ↩ | Ctrl+Z |
| Pause/Resume | Click ⏸️ | Space |
| Get hint | Click 💡 | H |
| Highlight number | Double-click cell | — |
Click Hint once to highlight the cell(s), then click again to see the explanation and apply eliminations.
| Level | Techniques Required |
|---|---|
| Easy | Naked singles only |
| Medium | Hidden singles |
| Hard | Naked pairs, common peer elimination |
| Expert | X-Wing and advanced techniques |
Start with Easy puzzles to learn the mechanics, then work your way up!
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