Sudoku Jigsaw Puzzle Rules

The objective of the puzzle is to fill the grid with numbers.These must be placed so that all numbers are used once, without repeating, with...

1. Last Empty Cell

If all other cells in a row, column or jigsaw piece are filled, there is only one possible number remaining to fill the last square.

2. Last Available Cell

Each jigsaw piece has a limited number of empty cells.The numbers in rows and columns that cross the jigsaw shape can be used to eliminate p...

3. Last Possible Number

When looking at a single cell on the grid, check the jigsaw shape, row or column it sits in. If there are no other numbers which could be pl...

4. Naked Single

Use pencil numbers to enter the possible numbers for each cell. If there is only one number within a square, then there are no other po...

5. Hidden Single

Use pencil numbers to enter the possible answers for each cell.If a number only appears in these pencil numbers once in a row, column, or ji...

6. Naked Pair

This technique is used to eliminate pencil numbers. Use pencil numbers to mark the possible numbers for each cell.A naked pair is where, wit...

7. Naked Triple

This technique is used to eliminate pencil numbers. Use pencil numbers to mark the possible numbers for each cell.A naked triple is where, w...

8. Hidden Pair

Within a row, column or jigsaw piece, each number can only appear once. This means that if there are two numbers that only appear in the sam...

9. Hidden Triple

Within a row, column or jigsaw piece, each number can only appear once. This means that if there are three numbers that only appear in the s...

10. Pointing Tuple

Within a jigsaw piece, if all possible squares that can contain a number are in the same line, then the number cannot be anywhere else in th...

11. X Wing

An X Wing is a great way to eliminate pencil numbers by spotting a pattern in the available numbers.Find two parallel lines where there are ...

12. Y Wing

Look for a cell that contains only two possible pencil numbers:In the rows and columns of this cell, look for two other cells that each cont...

13. Swordfish

Similar to an X Wing, look for three rows or columns where the same number only has two possible locations. In this example, the number...

14. Locked Candidate

This is the reverse of pointing pairs. If, within a row or column, all possible locations that the number can appear are in the same jigsaw ...