Sudoku Variants Series (415) - Parity Poopers
(Published on 14. March 2025, 12:00 by Richard)
Logic solvable
Parity Poopers
Inspiration for this type comes from aleph-0.
Solve online in Penpa+ or in Sudokupad.
Like all of my sudoku variants, this puzzle can be solved by logic alone. Guessing is not required and also no sophisticated solving techniques are necessary; just plain and easy sudoku steps and of course the intrinsic logic this specific variant has to offer. In case you don't find that logic or get stuck, feel free to ask for a hint in the comments below this puzzle and I'll be happy to help you.
Apply classic sudoku rules.
Digits in grey cells are parity poopers: digit N in a grey cell has exactly N-1 digits of opposite parity (odd/even) in the horizontal, vertical and diagonal adjacent cells. (An 8 in a grey cell has exactly 7 odd digits around it; a 5 exactly 4 even digits etcetera.)
All possible grey cells are marked!
Solution code: Column 8
Comments
on 4. January 2026, 19:43 by Rollo
Sehr schön! Letztendlich logisch gelöst, aber in 350 Minuten :-/.
on 23. December 2025, 23:10 by dzamie
Man, at least a quarter of this puzzle's difficulty definitely comes from trying to remember the parity flips. "Okay, this is a six, so that means six around it- no, FIVE, are even... no, wait, five are odd, so THREE are even."
Took me several false starts that I'm not entirely sure where I went wrong on, but ultimately, I was able to solve it well. The negative constraint proved remarkably useful!
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Thanks for the solve and your comment dzamie!
This puzzle is indeed only solvable if you can concentrate on it and keep carefully counting. And to do so with the inverse parity is not easy at all. It took me a while before I got my head around it too. :-)
on 29. August 2025, 00:13 by pin7guin
Wunderschön logisch lösbar - und immer dran denken: Parity ;-)
on 20. May 2025, 18:24 by LordM
Am Anfang viele Optionen ausprobiert, dann lief es flüssig.
on 5. April 2025, 09:13 by Bankey
Fun puzzle. Thanks, @ Richard :).
on 23. March 2025, 14:31 by Johan
Had to restart very often because I made a mistake somewhere again.
Despite the fact that I solved it by trying a lot, I still have no idea how I could do it better next time. The comment "Logic Solvable" is too much for me.
on 19. March 2025, 23:41 by Piatato
Lovely!
on 16. March 2025, 17:32 by Fra314
Brilliant construction, that last deduction was super neat (well, all of them actually)!
on 14. March 2025, 19:34 by Franjo
Maybe’s a 3.5-stars-puzzle? This ruleset was new for me. Interesting, but it was quite hard to get my brain around it. Well, in the end it was a satisfying solve. Thank you very much for creating and sharing this unusual beauty.
on 14. March 2025, 14:51 by marcmees
Brilliant, It seemed a bit tougher than the average SVS puzzle. Thanks
on 14. March 2025, 12:32 by SirWoezel
Lol. Nice title!
