Normal sudoku rules apply. In cages digits must sum to the small clue in the top left corner of the cage. Digits cannot repeat in a cage. In addition, every cage contains kropki dots that must be located by the solver. A black dot between two cells means that one of the digits in the cells is exactly double the other. A white dot between two cells means that the two digits in the cells must be consecutive. The exact number of dots of each type are the digits in the cage sum total. For example, a 21 means there are either 2 black dots and 1 white dot or 2 white dots and 1 black dot. Within a cage, all possible kropki dots would have to be given. Dots between a 1 and 2 could count for either black or white.