Normal sudoku rules apply. Digits along the 'cue' increase from the butt/bulb. Digits connected by a black dot have a 1:2 ratio. The white circle (cueball) contains an odd digit, the blue square (chalk) an even digit. The two cages contain 2-digit numbers that sum to 147, and the perimeter of the grid also sums to 147. Each of boxes 2 to 7 includes a horizontal domino containing 1N, where N is the box number. The 1 always comes first.