Logic Masters Deutschland e.V.

Normal sudoku rules apply.

Digits in a cage cannot repeat and all cages sum to the same total. However the value a digit contributes to the cage sum can be altered by the Vampire rule.

Each row, column, 3x3 box and cage contains one vampire cell and one prey cell. Each digit 1-9 appears once in both roles and a cell can't have both roles. In cages prey cells contribute 0, and vampire cells contribute the sum of its own digit and the digit of prey cell in the same 3x3 box.

Play this puzzle on CtC web app

Alternative version where 4 given digits are marked with smaller font is here. This allows one to use center or corner marks on these cells.

4x4 Example

Vampire cells are circled. Prey cells are crossed. All cages sum to 11. link