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# Irregular Sudoku

Irregular Sudoku Instructions:
Here's how to play Irregular Sudoku:
The instructions are as with sudoku: place 1 - n once in each row, column and bold-outlined region.

However, unlike sudoku, the bold-outlined regions are not regular 3 x 3 boxes, but rather all sorts of irregular shapes that fit together like jigsaw pieces: hence the other name for this puzzle, jigsaw sudoku.

Irregular sudoku puzzles can be quite a lot harder than standard sudoku puzzles.

This is due to the fact that the irregular regions are harder to keep track of with the eye and the pencil making pencilmarks, and so quite often one can forget that cells that are quite distant from the one you are looking at can affect the value of that cell (if they are in the same irregular region that, say, wanders across the grid considerably).

Some people prefer irregular, or jigsaw, sudoku to the regular puzzle, because each puzzle grid is different and plays differently due to the differing irregular shaped regions, in contrast to regular sudoku where the regions are always the same.

There is a huge range of different shapes for the jigsaw regions, and sometimes these will be symmetrical and other times not so. There are some grid patterns where there are a huge number of valid sudokus that can be made whilst there are others where none at all can be made!

Typically with a jigsaw sudoku one would expect to see less givens than with a regular sudoku due to the restrictive impact that the irregular shaped regions have on the solve path and thus potential values for each cell compared with regular 3x3 regions.

The actual rules that one uses to solve jigsaw sudoku are as with normal sudoku but one may find that certain rules get used more frequently than with standard sudoku in order to make progress.

### Related puzzles

Arrow Sudoku, Calcudoku, Circle Sudoku, Consecutive Sudoku, Futoshiki, Graeco-Latin Sudoku, HyperSudoku, Isosudoku, Killer Sudoku, Offset Sudoku, Outside Sudoku, Samurai Sudoku, Star Sudoku, Sudoku, Sudoku X, Toroidal Sudoku

Last updated: 14 Feb 2012

Sample puzzle:

Sample solution:

View a sample Irregular Sudoku PDF

Play Irregular Sudoku Puzzles:

To play this puzzle type online, visit the Jigsaw Sudoku page at the Puzzle Club with lots of irregular sudoku to play online at 6x6 and 9x9 sizes.

Play on paper:

If you prefer to play irregular sudoku on paper, then you can download and print a PDF containing 100 jigsaw sudoku puzzles and solutions via Jigsaw Sudoku Magazine.

Publish Irregular Sudoku Puzzles: