Logic Masters Deutschland e.V.

Anti-Anti-Knight (Whispers/XV/Kropki)

(Published on 28. July 2026, 09:02 by Kutsumi Hane)

Rules:

Normal Sudoku rules apply, requiring that each row, column, and 3×3 box contains the digits 1-9 exactly once. Additionally:
    ·Toroidal Grid: The grid wraps around both horizontally and vertically;
    ·Anti-Anti-Knight: Every cell has at least one knight-move neighbor with the same digit;
    ·German Whispers: Adjacent digits on green lines must differ by at least 5;
    ·Kropki Dots: Black dots indicate a 1:2 ratio between the digits;
    ·XV: Digits separated by an X sum to 10, and by a V sum to 5.

    Here you can solve the puzzle online:
    Solve on SudokuPad
    Solve on PuzzleTV (Developed by Chameleon)
    The difficulty is probably 2-3 stars. I wish you joyful solving!

    Hint:

    · Start with the high-low alternation on each German Whispers line.
    · During the solve, it may be helpful to check each cell's candidates against those of its knight-move neighbors – if a digit doesn't appear in any neighbor's candidate list, it can't go in that cell.

    Solution code: Column 8

    Last changed on on 28. July 2026, 18:36

    Solved by PippoForte, RebelSystem, wuc, hige, wangli19890129, jhrdina, Ftown778, raaaaa, Bjd, Elliott810, philolologue, butch02, MartinR, Kabuki73, LLX, zimorodok, garage, OlafLemme, Miatc, damyan_rm, ... paintspotinfez, saxdaddyj, thomamas, Sudokujoker, Elizy, Stargazing Albatross, MathingChar, itsid, ggwp, QuiltyAsCharged, Megalobrainiac, TroublesomeOrca, ShiZinDle, ebulku, mcs131313
    Full list

    Comments

    on 30. July 2026, 20:40 by Sudokujoker
    Very nice design - a fun solve path and a great introduction to the concept of a pro-knight constraint. Thanks!

    on 29. July 2026, 14:25 by LeaVulpina
    Very nice! A little brain-bending to scan, but fun the whole way through!

    on 28. July 2026, 11:55 by philolologue
    This was insanely fun! Not sure I'd give it 3 stars for difficulty, closer to 1.5 stars, no difficult deductions or places to get really stuck, just pure fun chasing the constraints, took about 25 min for me. Don't be intimidated by the toroidal constraint, just mentally transpose any edge column or row to the opposite side of the grid to visualize the cells a knight's move away.

    on 28. July 2026, 10:41 by Kutsumi Hane
    Editor's note: The solution code has now been simplified.

    Last changed on 28. July 2026, 10:37

    on 28. July 2026, 10:27 by wuc
    Refreshing puzzle. Loved the extrapolation logic. Great setting thx. (Solution code long for smartphone)

    ---
    Response from Kutsumi Hane:
    Thanks! Appreciate the feedback. I'll trim the solution code down to a cleaner version right away. Glad you enjoyed the logic and setting.

    Difficulty:2
    Rating:86 %
    Solved:78 times
    Observed:0 times
    ID:000U2V

    Variant combination Wraparound

    Enter solution

    Solution code:

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