Jigsaw Sudoku is a variant of classic Sudoku. In this puzzle, the 'nonets' (areas of the grid which must contain one of each digit to solve the puzzle) can be irregular shapes other than squares or rectangles.
How to play
Jigsaw Sudoku puzzles can have grids of different sizes. For smaller grids, a smaller set of numbers is used than the typical 1-9 digits.
Deduce which number goes in each square by a process of logical deduction. Each different colored region of the grid (shape) must contain exactly one of each number. As with a standard Sudoku puzzle, each row or column of the grid must also contain exactly one of each number.
You can select the difficulty level for each Jigsaw Sudoku puzzle - select Quick or Super Quick difficulty to have more numbers filled in at the start of the puzzle.
Tap on a grid square to select it, then use the keypad buttons below the grid to enter numbers.
The top row of buttons enter numbers in pen (indicating that they're part of the final answer). The bottom row allow you to enter numbers in pencil, to help keep track of which numbers are still valid for that square.
You can erase numbers you've entered by reselecting the square you want to edit, and using the keypad buttons to 'switch off' (erase) entered numbers.
When a pen number is entered (whether it's correct or not), all the pencil numbers that this placement would invalidate are removed from the grid. (If you place a pen number by accident, selecting 'Undo' from the status bar area will also replace any pencil numbers that were removed, so you don't lose track.)
If you try to enter a pen number on a line or in a shape which already contains one of that number, the number will be rejected. You will need to erase the existing number in that area before you can place it somewhere else.
When you tap to select a grid square containing a (pen) number, all the squares containing that number (in pen or pencil) will be highlighted. This can be useful to read the board more easily once a lot of numbers have been entered.
Deduce which number goes in each square by a process of logical deduction. Each different colored region of the grid (shape) must contain exactly one of each number. As with a standard Sudoku puzzle, each row or column of the grid must also contain exactly one of each number.
You can select the difficulty level for each Jigsaw Sudoku puzzle - select Quick or Super Quick difficulty to have more numbers filled in at the start of the puzzle.
Tap on a grid square to select it, then use the keypad buttons below the grid to enter numbers.
The top row of buttons enter numbers in pen (indicating that they're part of the final answer). The bottom row allow you to enter numbers in pencil, to help keep track of which numbers are still valid for that square.
You can erase numbers you've entered by reselecting the square you want to edit, and using the keypad buttons to 'switch off' (erase) entered numbers.
When a pen number is entered (whether it's correct or not), all the pencil numbers that this placement would invalidate are removed from the grid. (If you place a pen number by accident, selecting 'Undo' from the status bar area will also replace any pencil numbers that were removed, so you don't lose track.)
If you try to enter a pen number on a line or in a shape which already contains one of that number, the number will be rejected. You will need to erase the existing number in that area before you can place it somewhere else.
When you tap to select a grid square containing a (pen) number, all the squares containing that number (in pen or pencil) will be highlighted. This can be useful to read the board more easily once a lot of numbers have been entered.
Basic strategies
You may find it easier to try to tackle each set of the same number (e.g. all the '1's, '2's, etc.) one at a time:
Choose a number of which there is already at least one on the grid, and systematically mark (in pencil) all the valid squares in each shape that could contain that number, remembering that squares in the same row, column or shape as a placed number can't contain another of that number.
Choose a number of which there is already at least one on the grid, and systematically mark (in pencil) all the valid squares in each shape that could contain that number, remembering that squares in the same row, column or shape as a placed number can't contain another of that number.
Sometimes this will reveal shapes where only one valid position remains (which can then be entered in pen). You can also eliminate squares which (if the number was placed there) would cause all the valid squares remaining for the number in another shape to be invalidated. Furthermore, you can eliminate squares in cases where you've determined that the number must appear on a different row or column in that shape.
A quirk of Jigsaw Sudoku puzzles is that if the grid is split into two sections along a horizontal or vertical grid line, any partial shapes on each side of this 'border' will contain the same numbers.
A quirk of Jigsaw Sudoku puzzles is that if the grid is split into two sections along a horizontal or vertical grid line, any partial shapes on each side of this 'border' will contain the same numbers.
The easiest way to visualise this would be to consider an six square tall 'L' shaped shape at the edge of a 7x7 grid, with the 'foot' of the 'L' extending one square into the second column. If we know the number in the foot of the 'L' is a 7, we can deduce that the only square in the first column not contained within the shape must also be a 7 (as the rest of the line - within the L shape - must contain numbers 1-6).
There are more strategies for solving Jigsaw Sudoku that you'll discover through practice. Don't forget you can try playing smaller grids, and using the Quick or Super Quick options or the helper hints (below) to familiarise yourself with this puzzle type before attempting the 9x9 grids.
There are more strategies for solving Jigsaw Sudoku that you'll discover through practice. Don't forget you can try playing smaller grids, and using the Quick or Super Quick options or the helper hints (below) to familiarise yourself with this puzzle type before attempting the 9x9 grids.
Extra help
If you're stuck on a Jigsaw Sudoku puzzle, you can use coins to buy hints.
Hints can be used by tapping on the relevant icon in the status bar area at the top of the screen.
The cost (in coins) to use each hint is printed under its icon.
Hints can be used by tapping on the relevant icon in the status bar area at the top of the screen.
The cost (in coins) to use each hint is printed under its icon.
■ Solve Cell
Use this hint to put the correct number into the currently selected square only.
■ Show Pencil Numbers
Use this hint to automatically pencil in all the remaining valid numbers in every unsolved square on the grid.
■ Check for Errors
Use this hint to highlight (in red) any squares containing incorrect values. You can then select those squares and use the keypad buttons to remove the incorrect numbers.