Extra Region Sudoku puzzles is standard Sudoku variation very near to Classic Sudoku puzzle where some Extra Region of some cells is given. This Extra Region contain the unique digits i.e. no number is repeated in this given Extra Region. This Sudoku type was part of World Sudoku Championship 2015 (WSC 2015) and many puzzles of this type came in this championship. Currently there are very few Sudoku puzzles of this type published here. However I have prepared many puzzles of this type for preparations of WSC 2015 which I will be posting soon. On this page I will be giving links to all these puzzles.
Rules of Extra Region Sudoku
Classic Sudoku Rules apply. Additionally each group of nine colored cells must also contain the numbers 1 to 9.