Sudoku
Today sudoku is, without doubt, the most popular logic puzzle. Although it seems simple, its solving requires numerous strategies. The first sudoku was made about thirty years ago.
Sudoku variants
Besides classical sudoku, there are many variants that add to the popularity of this puzzle. Here we show you some of them.
Diagonal sudoku (sudoku X)
Fill in the grid so that every row, every column, every 3x3 box and both long diagonals contain the digits 1 through 9.
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Irregular sudoku
Fill in the grid so that every row, every column, and every (irregular) box contains the digits 1 through 9.
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Killer sudoku
Fill in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 9. The sum of the cells in a cage must equal the total given for the cage. Each digit in the cage must be unique.
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Odd-even sudoku
Fill in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 9. White cells can contain only odd numbers, while coloured cells can contain only even numbers.
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You can download some of these puzzles in PDF format:
diagonal
irregular
killer