# Killer Sudoku X Strategy

Killer Sudoku X is definitely an acquired taste - it combines many elements that you need to think about in order to solve a puzzle.

Not only must you remember the usual rows, columns and boxes of sudoku, you also have the main diagionals from sudoku X to consider.

And one more thing - you have no clues, but rather the kakuro like element of being told the sum of certain sets of boxes on the puzzle - all of which can make it a bit of a headache to solve.

The main tip is perhaps like killer sudoku to remember to use the rule that each row or column must sum to the sum of the series 1 - 6 or 1 - 9 depending on the size of the puzzle.

Thus, if you have for instance a 6 x 6 puzzle and the boxes in the top row tell you that the first three cells sum to 9, as do the 4th and 5th cells, then you know instantly the value of the final cell in that row - it is a 3 (which is 21 - 18). This is obvious once you are told it, but it may not occur immediately to you.

Using this rule is one of the most important to solving killer sudoku X, and should be employed frequently.

Also be sure to apply the usual sudoku elimination methods, and the use of the different types of pairs to further your progression through the puzzles. Good luck!