Empty Vessels
(Published on 14. April 2026, 08:28 by Die Hard)
Normal sudoku rules apply.
If the digit N appears in any of the four cells adjacent to a circle then it appears exactly N times adjacent to a circle across the grid.
Box borders divide blue lines into regions of equal sums.
Adjacent digits on red lines alternate between odd and even.
Adjacent digits on green lines differ by at least 5.
Digits on a pink line form a consecutive set in any order.
Please leave a comment if you enjoy this puzzle.
Solution code: All nine digits from row one.
Comments
on 27. May 2026, 19:27 by Morisenseiisgod
Monstrously hard but very rewarding! Took me 3 hours. I thought I was going well, but then I forgot r8c2 was a quad cell and broke the puzzle consequently so I started again.
on 29. April 2026, 20:26 by Wampoe
Expected a monstrously hard puzzle, but it flowed very nicely and every deduction came naturally
on 28. April 2026, 19:39 by Qodec
Extraordinary.
on 28. April 2026, 17:06 by willzz1122
Thank you so much for publishing this puzzle! I really needed a break from studying, so this kept me occupied for a while.
I really enjoyed the disambiguation of the 1s and 3s as my (the?) last step by using b2, 8, and 9. While a simple point, it feels very satisfying to know I had to work for each digit placed instead of just using Sudoku towards the end.
on 17. April 2026, 16:06 by Arheus
This is the hardest puzzle that I've managed to finish by myself. Simply amazing. Thank you!
Die Hard: Well Done! It looks like innocuous rules and the first 2 digits are pretty straightforward. But then...
on 15. April 2026, 17:21 by Snookerfan
Very nice puzzle! I feel like I should have understood just a little bit more of the underlying logic to make the solve smoother. I felt being so close all the way, but just not there. Thanks for the challenge!
Die Hard: I did work on many variations for a few weeks to try to make it smoother, but it would not cooperate. Sometimes you feel like you have made a close to perfect puzzle (eg: Third Order Logic) where one deduction leads to the next. This is not at that level, but I still felt there were some super interesting deductions that needed to be made, and it was worth publishing.
on 15. April 2026, 14:19 by Yaoning
Brilliant puzzle with a few standard sudoku structures and amazing Variant Sudoku rules just in their place. Thank you for creating this！
Die Hard: Thank you. I do like to try to create puzzles where the rules themselves are fairly standard and easy to understand, but yet there are some new and hopefully interesting deductions to be made.
on 15. April 2026, 02:06 by pmays123
Incredible puzzle filled with beautiful logic. Kept me entertained during my free time today. Thank you for sharing!
Die Hard: There are 3 or 4 needed logic steps that I really liked and they inspired me to complete and publish this puzzle. I'm glad you enjoyed it!
on 14. April 2026, 14:04 by EvaristeLogic
What an amazing puzzle!! Thank you :)
Die Hard: Thank you for solving it and commenting. I am glad you enjoyed it.
