Sudoku Jigsaw (also known as "Irregular", "Nonomino" or "Geometric Sudoku") is a logic-based, combinatorial number-placement puzzle.Jigsaw Sudokus are very similar to regular Sudoku puzzles. Regular 9x9 Sudoku that row and column rules apply, but instead of a 3x3 grid they are nime Jigsaw shapes.Each row, column and jigsaw shape contains all of the digits 1 through 9. In all other respects the puzzle works in the same way, but this change in the region shapes introduces new twists into the logic required to solve the puzzle - and often makes it much harder for you to find the next move as a result!Every Jigsaw Sudoku puzzle only ever has one possible solution, and it can always be reached via reasonable logical deduction. In other words, guessing is never required.