The case notes
How irregular regions work
Irregular regions replace the square boxes. Every row, column and region contains 1 to 9 once. Watch a worked example, then try the idea in a puzzle.
Follow the region borders
The usual square boxes are gone. In irregular Sudoku, the outlined regions bend into new shapes.
Nine cells, nine digits
This whole bent shape is one region. Just like a normal Sudoku box, it must contain each digit from one to nine once.
The bend connects them
The three at the end of this little extension belongs to the same region as this cell. So this other cell cannot be three.
Use the drawn regions
Rows and columns still work as usual. For the third group, follow the actual outline rather than an imagined three-by-three box.
Read the transcript
The usual square boxes are gone. In irregular Sudoku, the outlined regions bend into new shapes. This whole bent shape is one region. Just like a normal Sudoku box, it must contain each digit from one to nine once. The three at the end of this little extension belongs to the same region as this cell. So this other cell cannot be three. Rows and columns still work as usual. For the third group, follow the actual outline rather than an imagined three-by-three box.
