Logic Masters Deutschland e.V.

This puzzle combines zipper lines, Schrödinger cells and fog. See below for further explanations and an example puzzle.

• Normal Schrödinger Sudoku rules apply. Put one or two of the digits 0-9 in every empty cell such that each digit appears exactly once in every row, column and box.
• The grid is partially covered in fog. Placing correct digits reveals clues in the surrounding 3x3 area.
• Digits an equal distance from the circled center of a lavender zipper line sum to the same number.

Play Online on SudokuPad

Example Puzzle

Here is a 4x4 example puzzle (left) and it's solution (right). It can be played here. To fit 5 digits into 4 cells, each row, column and box must contain exactly one cell with two digits called a Schrödinger cell (S-cell). R1C2 is an S-cell that contains 0 and 1. It follows from the wording above that zipper lines only care about the sum of the digits in a cell so the top-left zipper is satisfied because 3+0+1=4. It is also possible that the circled centers of a zipper line are S-cells. The first deductions use the fact that all line-centers are circled.

Are You New to Those Constraints?

If you are not familiar with either S-cells or zipper lines and struggling with this puzzle, I recommend solving some introduction-level puzzles first. A totally Balanced Approach or Zip-a-De-Doo-Dah are introductions to zipper lines. Non-Separable States is an approachable introduction to S-cells. Schrödinger's Foggy Rationale also combines S-cells with fog.

Acknowledgements

Thanks to the S-cell expert ViKing Prime for test solving and the invaluable detailed feedback. Thanks to the CtC-fan-discord for testing. Recent constructions from Riffclown (and others) which brilliantly use lines that don't travel from cell centers but instead "overlap" with other lines were big inspirations. Lastly, thanks to Sirxemic for Sudoku Maker which makes typesetting these non-standard lines very convenient.