Normal sudoku rules apply. Values an equal distance to the circled centre of a lavender “zipper” line sum to the value of the central digit. Nine cells (one in each row, column and 3x3 box) contain a “Mirrored Digit”. A Mirrored Digit takes the value opposite to its digit on the 1-9 scale. (In other words, 1 takes the value of 9, 2 the value of 8... 9 the value of 1.) Each digit 1-9 is mirrored once. Unmirrored digits use their digits as values.