Online Sudoku is a javascript version of the popular japanese number game sudoku. This can be used to play sudoku online. Sudoku is a mind game and a puzzle that you solve with reasoning and logic. Fill in the grid with digits in such a manner that every row, every column and every 3x3 box accommodates the digits 1-9, without repeating any.

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Rules and Tips for Sudoku :
Among the simplest rules and tips for Sudoku is that there is only one solution to any given puzzle. Depending on the level of difficulty you are usually provided a set of starter numbers set throughout the grid to work with. Another of the simplest rules and tips of Sudoku is that the numbers which are 'given' to start cannot be changed. They are in the correct position to solve the puzzle.

The Rows :
As seen in the illustration below, here is a tip to one of the rules of Sudoku; in a traditional Sudoku puzzle, there are nine rows. Each row must contain the numbers 1 through 9 without duplication anywhere in the row.

# Fig 1

A B C D E F G H I
1 9       6       3
2 1   5   9 3 2   6
3 6 4     5       9
4 8           4 7 1
5 3   4 8 7
7   2 6   1     8
7 2
5       3 2   9 4
9 4 8 7   1 6 3 5

# Fig 2

9       6       3
2 1   5   9 3 2   6
3   4     5       9
4 8           4 7 1
5     4 8 7
7   2 6   1     8
7 2
5       3 2   9 4
9 4 8 7 9 1 6 3 5 2

# Fig 3

A B C D E F G H I
1 9       6       3
2 1   5   9 3 2   6
3   4     5       9
4 8           4 7 1
5     4 8 7
7   2 6   1     8
7 2 3 9
5 6 1   3 2   9 4
9 4 8 7   1 6 3 5
The Columns :
Looking at the illustration below, as with rows, another tip to a rule of Sudoku is that there are also nine columns in the traditional version of the game. Again, each column must have the numbers 1 through 9 without duplication anywhere in the column.
The Regions :
The last main tip to know is the Sudoku rule stating that a region is set up as a 3x3 grid, and like columns and rows, must contain the numbers 1 through 9 without repeating any number. Here is an illustration of a region.
Another tip and rule of Sudoku is that no two regions will be the same. This means that once a region is completed, that number combination will not be used again anywhere in the puzzle.

The simplest tip to remember about rules of Sudoku is that you complete the puzzle having every column, region and row containing the numbers 1 through 9 only one time each.

An added tip to remember Sudoku rules is that there is always only one solution to a puzzle.