Jigsaw Sudoku (Irregular Sudoku)

Same rules as standard sudoku — except the nine boxes are irregular connected regions instead of 3×3 squares. The shapes are generated randomly for every puzzle, so memorised patterns won't help.

Rules

• Every row and every column contains 1-9 with no repeats.
• The nine irregular regions each contain exactly 9 cells, and each must hold 1-9 with no repeats.
• Region shapes are randomised per puzzle — there is no fixed pattern to memorise.
• A boundary segment always separates two regions, so twistier borders carry more information.

Solving Tips

• Learn the region shapes first: jigsaw borders cut across rows and columns and often eliminate faster than standard boxes.
• Hunt for narrow, squeezed regions — a region pinched into a line is extremely constrained.
• Since boxes no longer align with the grid, run cross-hatching against rows, columns and regions together.
• When stuck, look for a hidden single: a digit with only one possible cell left inside a region.