Suguru is a logic puzzle played on a grid divided into irregular regions. Each region must contain every number from 1 up to the number of cells in that region, exactly once. For example, a region containing four cells must contain the numbers 1, 2, 3 and 4. Cells that touch horizontally, vertically or diagonally cannot contain the same number. The objective is to fill the entire grid while satisfying both the region rules and the neighbouring-cell rules. Unlike Sudoku, Suguru uses irregular regions and diagonal adjacency.