Logic Masters Deutschland e.V.

More information about my Double Trouble series as well as links to the other puzzles of the series can be found below the puzzle.

Rules:

Sudoku: Fill every row, column and 3x3 box with the digits 1-9.

XV (extended):
Cells seperated by a V sum to 5.
Cells seperated by a X sum to 10.
Cells seperated by a XV sum to 15.
Cells seperated by a XX sum to 20.
Not all possible clues are given

Double Trouble: Digits in cells marked with a blue diamond contribute the double value to calculations.

Have fun solving!

Sudoku on:
f-puzzles
CTC-App

The Double Trouble series:
It's a simple idea. Treat a few cells as if they are double their value. But it has tons of interesting logic and can turn known rule variations completely upside down. With this series I want to show this diversity.

Variant introduction: Easy to moderately difficult puzzles that show the combination of doubling cells with different variants.
Double Trouble - Arrows
Double Trouble - Killer
Double Trouble - Skyscraper

Puzzles with hidden doubling cells: The doubling cells are not given here, but must be determined by the solver.
Doubles Hidden Inside Squares

I look forward to any feedback and suggestions about the series.