Argyle sudoku is a variant of sudoku (funnily enough) that has various additional regions.
The extra regions form a pleasant-looking criss-cross pattern. What is interesting about the extra regions is that they are partial - unlike something like Sudoku X they are not of length 9, in a 9-by-9 puzzle.
Therefore there are slightly different bits of logic that you can use to help solve these puzzles and that makes a pleasant change from ordinary sudoku, in a similar sort of way to the way that you use partial elimination logic when solving puzzle types such as isosudoku that also have some partial regions in them.
How to solve Jigsaw Sudoku Been tempted by jigsaw sudoku but found it too tricky, or perhaps you've tried but got stuck? This video walks through the solve of a jigsaw (irregular) sudoku, and you can try the puzzle before you watch...
