Jigsaw Sudoku relaxes the requirement of square blocks as in regular Sudoku puzzles. Instead, non-square rectilinear shapes made out of contiguous cells are used instead. The requirement that rows and columns each have unique digits is still true, however.
Some sites that offer Jigsaw Sudoku puzzles include: Puzzle Club, Competition Jigsaw Sudoku and a site offering Sudoku Variants And Other Number Placements.
[…] This cartoon is comparable to the cartoon I published last June 2, 2007, called Jigsaw Sudoku where numbers instead of letters were used. […]