How to Play Hyper / Windoku

Hyper Sudoku (also called Windoku or Hyper-Sudoku) adds four shaded 3×3 regions to the standard 9×9 grid. Each shaded region, like a standard box, must contain the digits 1–9 exactly once. This gives a total of 13 uniqueness groups: 9 rows, 9 columns, 9 standard boxes, and 4 hyper regions — though many cells overlap between groups.

The four hyper regions are positioned symmetrically, offset from the standard boxes. They occupy the 3×3 areas starting at 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 hyper region overlaps with four standard boxes, creating a dense web of mutual constraints.

Any cell inside a hyper region carries five constraints simultaneously: its row, column, standard box, and the hyper region. This extra constraint eliminates candidates faster than standard Sudoku. After every digit placement inside a hyper region, scan all five groups for new eliminations.

Easy Hyper Sudoku is often easier than equivalent classic Sudoku because the extra constraints resolve the grid more quickly. Hard and expert Hyper puzzles are comparable in difficulty to their classic equivalents — the additional constraints help but also create complex multi-group interactions that require careful tracking.

Focus on cells inside hyper regions, especially those at the intersections of a hyper region and a standard box. These carry the most constraints and are the most likely to resolve immediately. Always scan all four hyper regions after every placement.

Easy puzzles take 5–12 minutes — often faster than classic Sudoku of equivalent difficulty. Medium puzzles run 12–25 minutes. Hard and expert puzzles take 25–60 minutes. The extra regions speed up early solving but hard puzzles compensate with fewer given digits.