Hyper region
One of the four extra 3×3 regions in a Hyper Sudoku (Windoku). Each region carries the same digit-uniqueness rule as a row, column, or standard 3×3 box.
A hyper region is one of the four extra 3×3 regions overlaid on a Hyper Sudoku board. Each region carries the same digit-uniqueness rule as a row, a column, or a standard 3×3 box: every digit from 1 to 9 must appear in the region exactly once. The hyper regions are visually marked on the board with a coral outline so they're recognisable at a glance.
Where they sit
The four hyper regions occupy fixed positions inside the 9×9 grid: rows 2–4 columns 2–4, rows 2–4 columns 6–8, rows 6–8 columns 2–4, and rows 6–8 columns 6–8. Each region sits inside one of the four quadrants of the board, offset by exactly one cell from the corner in each direction. The four regions don't touch each other; the space between them forms a plus-shaped gap running through the middle of the grid.
There are 36 hyper-region cells in total — nine cells per region, four regions, no overlap. The other 45 cells of the board lie outside any hyper region and follow only the classic row, column, and box rules.
What it adds mechanically
For cells inside a hyper region, the hyper region acts as a fourth unit, in addition to the cell's row, column, and standard 3×3 box. Every classic Sudoku technique that fires on a row, column, or box also fires on a hyper region — naked singles, hidden singles, pairs, triples, locked candidates, all of them work identically.
The hyper region's geometric position is what makes it valuable. Because each region is offset by one cell from the corner of the board, it overlaps four different standard 3×3 boxes — never just one. A placement inside a hyper region therefore propagates constraints across four boxes at once, which is the structural fact behind cross-region deduction and the variant's overall connected-feeling solve.
See also
- Hyper Sudoku— A Sudoku variant with four extra 3×3 regions overlaid on the standard grid, each obeying the uniqueness rule. Also called Windoku in continental European communities.
- Windoku— An alternate name for Hyper Sudoku — the 9×9 Sudoku variant with four extra 3×3 regions overlaid on the grid. The original Dutch name from NRC Handelsblad.
- Hyper-only cell— A Hyper Sudoku (Windoku) deduction: a cell where row, column, and standard box together leave multiple candidates, and the hyper region alone forces the digit.
- Hyper pair— A naked pair where both cells lie in the same hyper region of a Hyper Sudoku (Windoku). Eliminates the two pair digits from every other cell of that region.
- Cross-region deduction— A Hyper Sudoku move using the overlap between a hyper region and a standard 3×3 box: locking a digit to a shared sub-region eliminates it from the rest of both units.
- Unit— Collective name for a row, column, or 3×3 box — the three groupings Sudoku's no-repeats rule applies to. Every cell sits in exactly three: its row, column, and box.
Read more
- The four hyper regions
Where the four extra 3×3 regions sit inside a Hyper Sudoku (Windoku) board, why they're positioned that way, and how to spot them while solving.
- The rules of Hyper Sudoku
Hyper Sudoku — also known as Windoku — is classic Sudoku with four extra 3×3 regions overlaid on the grid. Each of the four hyper regions obeys the uniqueness rule.