Logic Masters Deutschland e.V.

Rules:

• Normal sudoku rules apply.
• Every 2x2 area of cells in the grid must contain at least one digit from each of the following sets: (1,4,7), (2,5,8), (3,6,9).
• Box borders divide blue lines into segments of equal sums.
• The difference between digits across a black diamond must be a multiple of three.
• One digit must be double the other digit across a black dot.