Normal sudoku rules apply. Clues outside the grid are X-Sums. Ie They represent the sum of the first X digits in the row/column where X is the first number along that row/column. In cages, digits sum to the total indicated in the top left corner of the cage. Digits cannot repeat in a cage but the killer cages themselves must be deduced by the solver! Each cage is in the same row or column as its associated X-Sum clue (colour coded for clarity). The cage can have any shape but its number of cells must be equal to X (ie X from its associated X-Sum clue). A killer cage total must always be at the top left corner of its cage and cages may not overlap.