Normal sudoku rules apply. There are nine doubler cells in the grid, one in every row, column and box. Each digit from 1-9 appears in a doubler cell exactly once. A doubler cell's value counts as double its digit. Along a green line, values of neighboring cells must differ by at least 5. For cells separated by an ‘x', the two cells' values must sum to 10. For cells separated by a white dot, the two cells' values must be consecutive. For cells separated by a black dot, one cell's value must be double the other. For cells separated by a grey dot, one cell's value must be triple the other.