Why is it called Jigsaw Sudoku?
The irregular regions look like jigsaw puzzle pieces.
Are the rules the same as Sudoku?
Yes, except the boxes are irregular shapes instead of 3x3 squares.
Is Jigsaw Sudoku harder?
It can be, because irregular regions create less familiar candidate patterns.
How many cells are in each region?
Exactly nine, the same as a standard box.
Can regions touch only at corners?
Regions are contiguous groups of cells; they do not overlap.
