Logic Masters Deutschland e.V.

After S-cells, negators, doublers and mirrored digits I waned to combine vampires with zipper lines. See the example puzzle below for an example puzzle with vampire cells and zipper lines. Thanks to the CtC-discord for testing.

• Normal Sudoku rules apply.
• The grid is partially covered in fog. Placing correct digits reveals more clues.
• 9 cells in the grid (one per row, column and box) are vampire cells. Each digit 1-9 appears in a vampire cell. 9 cells in the grid are prey cells which follow the same restrictions as vampire cells. A vampire cell can't also be a prey cell.
• Prey cells have a value of zero. Vampire cells use the sum of the digits in the vampire cell and prey cell within the same box as their value.
• Values an equal distance to the circled center of a zipper line sum to the value of the central cell.

Example

In this example, vampires are highlighted in red and prey are highlighted in blue. Each digit appears exactly once in a red cell and exactly once in a blue cell. The short zipper line contains no modifiers and can be read as 3=1+2. The long line has a vampire with value 5 (1+4) in its center. The first two equidistant pairs (23, 14) each sum to 5. At the end of the long line, there is a prey cell (value 0) opposite a vampire cell (value 2+3) so the values also add to 5.