Normal sudoku rules apply. No two cells in the same position within a box can contain the same digits. (Eg r1c4 and r7c7 must be different as both occupy the first cell of their boxes). The cells separated by the black dot have a ratio of 2:1. (Not all possible dots are given). Digits on a purple line must be between the circled digits at the line's ends. The upper right vertical line is an arrow. The digit in that circle is the sum of the digits along the arrow.