What is Jigsaw Sudoku?
Jigsaw Sudoku (also called Irregular Sudoku or Nonomino) is a 9×9 Sudoku where the nine 3×3 boxes are replaced by nine irregular shapes. Fill the grid so each row, each column and each shape contains 1 to 9 exactly once.
In Marble Sudoku this mode is called Mosaic: the board gets new walls, and each shape holds every marble colour once. The shapes make familiar patterns look new, so even experienced players have to look twice.
- 9×9 board
- Rows, columns and shapes
- Nine cells per shape
The rules
- 1Rows. Each row holds every number once.
- 2Columns. Each column holds every number once.
- 3Shapes. Each of the nine outlined shapes holds every number once.
- 4No boxes. The usual 3×3 boxes do not count. Only the shapes do.
Watch it on the board
- In Mosaic the boxes become shapes. Each shape has nine holes.
- Each shape holds every colour once. This one is missing just one colour.
- Rows and columns still count too, exactly as in Classic.
- Fill the last holes, and the mosaic is complete.
Tips
- Trace the shapes first. Before you start, follow each wall with your eye so you know which cells belong together.
- Watch the long arms. A shape that reaches into another row or column often pins a number into a single cell.
- Count bulges. If shapes cover a full set of rows, cells that stick out of them must match cells that stick in. This is called the law of leftovers.
- Use your usual techniques. Singles, pairs and X-Wings all work. Just use the shapes where you would use boxes.
Jigsaw Sudoku vs Classic Sudoku
| Jigsaw (Mosaic) | Classic | |
|---|---|---|
| Regions | Nine irregular shapes | Nine 3×3 boxes |
| Rows and columns | Still count | Count |
| Box techniques | Use the shapes instead | Use the boxes |
| Feel | Familiar logic in an unfamiliar layout | The standard puzzle |
Jigsaw Sudoku FAQ
What are the rules of Jigsaw Sudoku?
Fill the 9×9 grid so each row, each column and each of the nine irregular shapes contains the numbers 1 to 9 exactly once.
Is Jigsaw Sudoku harder than Classic?
Not by rule, but it can feel harder at first because the shapes break habits. Once you trace the shapes, the same logic works.
What is it called in Marble Sudoku?
Mosaic. The board gets new walls and each shape must hold every marble colour once.
Is it the same as Nonomino or Irregular Sudoku?
Yes. Jigsaw, Irregular, Nonomino and Geometry Sudoku are names for the same idea.
Do the 3×3 boxes still count?
No. Only rows, columns and the outlined shapes count. The usual box lines are gone from the Mosaic board.
PLAY IT IN MARBLE SUDOKU
Try Mosaic in Marble Sudoku
New shapes, same rules. Trace the walls, fill the shapes and watch the mosaic come together.
Next modeThermo Sudoku
