(+10)-Yang
(Published on 30. September 2025, 08:00 by Kaktuslav)
Rules: Normal sudoku rules apply.
Yin-Yang: Shade some cells in the grid so that all shaded cells are orthogonally connected, all unshaded cells are orthogonally connected, and no 2×2 region is entirely shaded or entirely unshaded.
Values: A shaded cell containing digit x has value x+10; an unshaded cell has value equal to its digit.
Region sum lines: Blue lines are divided into segments by box borders. All segments along a single line must have the same sum of values (this sum may differ between lines).
Kropki dots: Cells connected by a black dot have values, one of which is double the other. Not all dots are necessarily given.
Dynamic Fog of War: The grid is partially covered in fog. Placing correct digits reveals their own cell and may also lift fog elsewhere in the grid. No guessing is required.
Solution code: Row 2 (with the symbol "/" marking borders between shaded and unshaded cells, e.g. 123/4567/89)
Comments
yesterday, 18:50 by eap314
Reasoning about 2x2 restrictions helped a lot at the bottom. Definitely worth the 4 star rating, and I'm amazed I solved it in under 2 hours.
on 5. October 2025, 21:31 by nunc
Wow. There were times I wanted to give up. But then I found the next step, and it was totally worth it! Thanks.
on 4. October 2025, 10:13 by AdarshN
Really brilliant and beautiful puzzle! Love the ruleset and how it interacts across the different constraints. Some quite tough stretches of logic but well worth it!
on 4. October 2025, 04:14 by Voidslime
Absolutely incredible! I never expected to have to reason with YY in such a new unique way
on 4. October 2025, 04:14 by Voidslime
Absolutely incredible! I never expected to have to reason with YY in such a new unique way
on 3. October 2025, 02:37 by ViKingPrime
One of the best yin-yang puzzles out there (and that's some seriously stiff competition).
on 2. October 2025, 19:50 by LehanLehan
Piece of art, thank you very much for the puzzle.
on 2. October 2025, 01:49 by QuiltyAsCharged
Brilliant and challenging!
on 1. October 2025, 10:20 by Snookerfan
Great puzzle! Because of some hard steps in the midsolve, which included advanced connectivity issues, I rated it 4 stars. But there may have been an easier way which I missed. Thank you
on 1. October 2025, 08:15 by flutchman
Extraordinary puzzle. Well done!
on 30. September 2025, 21:07 by MattJones
Fantastic. So enjoyable, nicely challenging. Took me too long to spot some of the next steps, but the fault there was entirely mine!
on 30. September 2025, 20:14 by Exigus
Fantastic puzzle. The opening and all the fog reveal is so well constructed, it blows my mind. Thanks!
on 30. September 2025, 16:18 by Kaktuslav
Revising estimated difficulty based on suggestions from comments, thanks!
on 30. September 2025, 16:00 by VitP
yy puzzles are sufficiently complicated that they automatically START at level 2. THIS one is sufficiently harder than that to become level 3.
of course, it's a "must do" for yy fans.
hints:
1) +10 does not change parity
2) 17 is NOT a kropki digit
3) D +10 > 10
on 30. September 2025, 13:31 by wuc
Spectacular puzzle. YY from the center box is awesome. The 10+ was new to me. Although the fog helps its at least a 3* to me. Awesome setting thx.
