Jigsaw Sudoku
Sudoku with non-rectangular regions. same digit constraint, weirder shapes.
What is jigsaw sudoku?
Jigsaw sudoku. also called squiggly or geometric sudoku. keeps the row and column rules of classic sudoku but replaces the nine 3×3 boxes with nine irregular regions of nine cells each. The same digit constraint applies, but the geometry forces you to think spatially.
Rules
- Each row contains digits 1–9 exactly once.
- Each column contains digits 1–9 exactly once.
- Each irregular region of nine cells contains digits 1–9 exactly once.
Tips
- Long, snake-like regions create unusual elimination paths. scan them carefully.
- Pointing pairs and box-line reduction take on new forms; the 'box' is now whatever shape the region happens to be.
- Pencil marks are essential.
Related variants
- Diagonal Sudoku (X-Sudoku), Classic sudoku plus a constraint on both main diagonals.
- Hyper Sudoku, Classic sudoku with four extra 3×3 regions to satisfy.
- Killer Sudoku, Sudoku meets killer-style arithmetic: every dotted region sums to its total.
- Classic sudoku for comparison
Jigsaw Sudoku FAQ
What's the difference between jigsaw and classic sudoku?
Only the box shape. In classic sudoku, the nine boxes are 3×3 squares. In jigsaw, they're irregular polyominoes of nine cells each.
Are jigsaw regions always nine cells?
Yes. Every region in a 9×9 jigsaw sudoku has exactly nine cells; otherwise the digit constraint can't be satisfied.
Is jigsaw sudoku harder than classic?
Generally yes, because spatial intuition about boxes has to be rebuilt from the region shapes.
Can I use the same techniques as classic sudoku?
Most of them, yes. they just look different. X-wing and swordfish work identically; box-line reduction generalises to region-line reduction.
Are jigsaw puzzles unique?
Yes. Uniqueness is verified during generation.