Logic Masters Deutschland e.V.

Normal sudoku rules apply.

Mod-3 Counters: Circled digits indicate how many of the up to 9 cells surrounding the circle (including itself) have the same value modulo 3 as itself. E.g., a circled 4 would count how many of the surrounding digits are from the set {1, 4, 7}. Not all such circles are necessarily given.

Fog of War: The grid is partially covered in fog. Correctly placing digits will clear the fog around that cell. No guessing is required.

Play in the CTC App

Example for reference: