Normal sudoku rules apply, but the orthogonally-connected 9-cell regions must be determined. Clues outside the grid give the sum of all digits sandwiched between the nearest and farthest region border in that row/column. (Note: any row or column with a clue must contain at least two region borders.) For this purpose, the edge of the grid is not counted as a region border.
The corner clue on the positive diagonal works the same way, counting a region border each time adjacent cells along the diagonal are in different regions.
Here is an example puzzle to demonstrate the ruleset:
Solve online:
F-puzzles
Penpa+ (recommended)
CtC app
Solution code: Row 6, then column 6 (18 digits, no spaces).
on 14. May 2024, 23:22 by wuc
Chaos is the final boss for me. Fought a hard long fight. Definitely on my upper limit of skill. But what a great setting. No clue how you can set such a masterpiece. Great fun thx.
on 20. February 2024, 18:10 by Myxo
Wonderful construction!
on 3. August 2023, 23:33 by Bankey
Very tough, and great fun! Thanks, @ grkles :).
on 27. February 2023, 15:41 by Mr.Menace
Very nice and smooth chaos construction! Thanks sir grkles!
on 14. June 2022, 20:35 by Snookerfan
I Love chaos constructions and this was a great one!
on 13. June 2022, 11:14 by ICHTUES
Very cool! Once I was into the ruleset, it wasn't that hard anymore. I really enjoyed it.
on 7. May 2022, 17:17 by Florian Wortmann
Added to favourites :-)
on 22. April 2022, 03:54 by Agent
After breaking the puzzle twice, I was finally able to solve it. A fascinating idea and clever execution. Thanks!
on 20. April 2022, 17:58 by wildbush7
Wow, I'm completely stumped. Would love to see someone stream the solution to this.
~~~
@wildbush7 - there are a couple videos if you want to watch. wenchang posted one below, and also Niverio streamed a solve of it on Twitch here: https://www.twitch.tv/videos/1452867659?t=04h36m37s
on 19. April 2022, 21:08 by Playmaker6174
Really exceptional setting and a beautiful solve path! Despite the easy start, it actually tended to get harder and harder but no less interesting, particularly enjoyed some big deductions in later half :}
on 17. April 2022, 23:50 by wenchang
https://youtu.be/8Md8R4rph1A
very nice puzzle. A video in Chinese.
on 16. April 2022, 16:39 by twobear
Beautiful puzzle. Thank you!
on 14. April 2022, 10:04 by Christounet
Great puzzle with very nice contruction moments ! Love these chaos constructions, so much fun ! Thanks for setting this !
on 13. April 2022, 23:06 by MagnusJosefsson
Excellent puzzle! Very smooth and well balanced. Thanks!
on 12. April 2022, 16:09 by kolot
It was fun!
on 12. April 2022, 13:44 by grkles
Added example puzzle.
on 12. April 2022, 12:40 by Piatato
Fun and beautiful puzzle! I had a great time solving it!
on 12. April 2022, 09:31 by marcmees
Very nice. thanks.
on 12. April 2022, 05:45 by Elliptical
Fun puzzle. It started not too hard but got harder and harder.
on 11. April 2022, 22:11 by Niverio
Im glad you set a great puzzle, otherwise I would be upset with you stealing my CC idea :P Very nice.
on 11. April 2022, 21:55 by Jesper
Great puzzle, thanks
on 11. April 2022, 21:00 by Vebby
Excellent! Tough but fair solve path. Greatly enjoyed identifying and completing the regions. Thanks grkles! :)