Logic Masters Deutschland e.V.

Rules:

Normal sudoku rules: Place the digits 1 to 9 in each Row, Column, and 3X3 box.

Doublers: One cell in every row, column, and box is a Doubler cell, every digit from 1 to 9 must appear in a doubler cell exactly once. The value of a Doubler cell is equal to twice the digit it contains.

Arrows: Values along an arrow sum to the value in the attached circle.

Kropki: Cells separated by a white dot must contain consecutive values. Cells separated by a black dot have a 1:2 ratio. Not all possible dots are given.

Solve online: CTC, f-puzzles