Ratio lines - Dynamic fog
(Published on 31. July 2026, 05:56 by Killer Joe)
Hello.
Normal Sudoku rules apply.
On each line, the sum of either the odd digits or the even digits is exactly half or double the sum of the other parity.
Additionally, all end cells of any line contain digits of the same parity (all odd or all even).
Digits separated by a white dot are consecutive.
Entering correct digits may lift fog somewhere in the grid. No guessing is required.
Have fun.
Solution code: Row 9, first 6 digits.
Comments
on 30. August 2026, 02:07 by Kleiner_Lateiner
Straight forward start, a bit harder in the middle and then flying through the rest of the puzzle
on 20. August 2026, 22:18 by Jorssi
Very nice puzzle. I usually find every puzzle harder than their respective rating, but for some reason this was very easy for me, but still very enjoyable.
on 14. August 2026, 22:06 by kasperd
Nice original idea. I found the difficulty to be at the high end of two star puzzles, but not quite hard enough to rate it three stars.
on 13. August 2026, 13:40 by Rjw78
Ooh lovely puzzle. Found it hard though. I would give it a hard 3⭐️
on 12. August 2026, 21:45 by bboom
Fun one!
One suggestion for the wording of the rules. The first rule is needlessly complicated, because it has two 'or' clauses while there are only two real options.
It could simply be "On each line, the sum of the odd digits is exactly half or double the sum of the even digits."
Or alternatively "On each line, the sum of either the odd digits or the even digits is exactly half the sum of the other parity."
I think the first one is clearest, but both mean exactly the same as the original rule.
on 10. August 2026, 19:02 by BigHead
I absolutely loved it, thank you!
on 10. August 2026, 17:09 by OfishilNasser
Absolutely fantastic puzzle. Loved every second of it
on 9. August 2026, 23:41 by Fortunate
A very well constructed puzzle! From the break-in I knew I was going to enjoy it.
on 8. August 2026, 02:34 by Aous
One of the best sudoku ive ever done a perfect fog puzzle 10/10
3 stars for me. Thank you for sharing it.
on 2. August 2026, 22:04 by Voidslime
Wow what a great puzzle! The guided exploration used fog perfectly. This puzzle made new feel good about myself as strange as that sounds.
on 1. August 2026, 16:57 by Snaques
This was really fun and interesting. Quite a variety of logic that was required along the way so it took some time, but never felt overwhelming.
on 31. July 2026, 18:15 by Franjo
Thank you very much for creating and sharing this funny parity sums puzzle.
on 31. July 2026, 08:54 by Chaossudokusplease
Very nice puzzle, great fun! More of a 2-star for me but I’m used to parity sum puzzles. May I recommend you update the wording about line end parities (something like “on each line, the digits on every end are of the same parity i.e. all odd or all even”)? I initially interpreted it as a global rule where the ends of all lines in the puzzle are of the same parity. It broke pretty quickly so I realised not too far in but it might cause confusion for others too.
on 31. July 2026, 07:03 by Elliott810
Brilliant puzzle! For me 2.5* difficulty. Thank you:)
