Sudoku Odd-Even Usual sudoku rules apply. Also, the odd digits appear in the grey squares. Other Sudoku Style Puzzles Killer Sudoku Irregular Killer Sudoku Extra Region Killer Sudoku Colour Killer X Sudoku X-Factor Killer Sudoku Killer Sudoku Uncaged Colour Killer Sudoku Twins High Five Sudoku Mini MORE SYNDICATED CONTENT Featured Content for Children Digital Products Comics & Cartoons Games & Puzzles Infographics Quizzes Pages & Pull-Outs Columns & Fillers Themed Content News from Knight Features Syndication Department