Jigsaw Sudoku
Same digits, same uniqueness rules — but the nine regions are irregular shapes, not 3×3 boxes.
What makes it Jigsaw
The grid is still 9×9, and every row and column still needs each digit 1–9 exactly once. What changes is the third constraint: instead of nine 3×3 boxes, you get nine irregular regions, each one a connected blob of 9 cells.
It breaks every box-based reflex you've built up. Singles and pairs still apply, but you have to read the region shapes from the grid lines instead of muscle memory. Some jigsaws lean hard on the irregular regions for their early eliminations.
Rules
- Every row contains each digit 1–9 exactly once.
- Every column contains each digit 1–9 exactly once.
- Every irregular region (outlined in the grid) contains each digit 1–9 exactly once.
How Stillgrid plays
- Region boundaries drawn cleanly so you always know which shape you're in.
- Pencil marks, auto-pencil, undo/redo.
- Difficulty graded by the techniques needed against the actual region shapes.
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