Logic Masters Deutschland e.V.

Normal, Killer and Difference Sudoku rules apply. Each row, column, and 3x3 box contains each number from 1 to 9 exactly once. The sum of all numbers in a cage (marked with dashed lines) must match the small number printed in its corner. No number appears more than once in a cage. The numbers in the small circles between two cells indicate the difference between those cells

There are three additional rules, each belongs to exactly one color of Zedz, and does NOT apply to the two others. You have to determine what rule belongs to what color.

1) The highest and the lowest number in this killer cage must be in the two ends of the Zedz.

2) The highest and the lowest number in this killer cage must be in the two middle cells of the Zedz.

3) The sum of the two other color's secret (blank) difference clues divided by 2 is equal to the sum of this color's secret difference clues. For example: if color#1's and color#2's secret difference clues are 3+5+2 and 2+1+7, then the SUM of the secret difference clues of this type of killer cage must be (3+5+2+2+1+7)/2=10.

The puzzle is also available online.

This website can help a lot.