Normal sudoku rules apply. Divide the grid into 3 orthogonally connected sections such that each pair of sections shares an edge and no 2x2 square in the grid belongs to a single section. A digit in a circle indicates the number of circles in its section. On section-sum lines, all adjacent groups of digits along the line which are part of the same section have the same sum. No line can be entirely in one section.
If you prefer to play directly in sudokupad then click below.
