“Read Carefully” - A Kropki Sudoku
(Published on 31. August 2026, 01:04 by TheAuthenticCheese)
“Read Carefully” - A Kropki Sudoku
- Standard Sudoku Rules Apply.*
- Standard Kropki Rules Apply.*
- All possible dots have necessarily not been given.
*Standard Sudoku Rules
- Place the digits 1-9 once each in every row, column, and 3x3 box.
*Standard Kropki Dot Rules
- A white dot between two cells indicates that the digits in those cells are consecutive.
- A black dot between two cells indicates that the digit in one of those cells is twice the digit in the other.
Play on SudokuPad
Solution code: 3rd row from the top.
Comments
yesterday, 06:57 by TheAuthenticCheese
@zixx
That was intentional, hence the title! In a sense, there is a negative constraint… almost. It becomes necessary for the final disambiguation.
on 4. September 2026, 00:37 by zixx
Maybe it's me, but the "Not all dots..." rule just reads like there's no negative constraint. So I'm stuck with two solutions left. I think there's some confusion between "necessarily not" and "not necessarily" - they're not the same thing.
on 3. September 2026, 18:00 by TheJRMY
Personally I really enjoyed this. After finishing I undid quite a bit and resolved reversing the final disambiguation in order to see if there were really no missing white dots. Indeed it was true. Very interesting.
on 31. August 2026, 18:00 by PKMKII
Break in was pretty straightforward, gave it two stars for difficulty as I could see someone who isn’t used to the interplay of the two kropki dot types finding it a bit tricky. However, the deadly pattern situation docked my score.
on 31. August 2026, 17:13 by TheAuthenticCheese
Thanks for all the feedback! In hindsight I definitely should have considered the translation issue. I’ve added the English Language skills tag :)
@MartinR, thank you! I had no idea the negative constraint (no dot = no relation OR all dots given) was considered part of “standard.” I tried looking it up but couldn’t find a clearly definitive set of rules, hence putting in the clarifications. In the future I will leave out the “standard” and just list all rules explicitly.
Regarding the trickiness of the language, that was somewhat the whole idea that started this puzzle. I toyed around with different phrases and went with this one because I liked how it used all the same words as the common “Not all possible dots have necessarily been given” and just moved the word “not” leading to a different meaning. A logically equivalent, (though less sneaky) rule would have been “At least one possible dot is missing” which I believe would lead to the same disambiguating case on R2C1/R2C2. But I wanted to play with the idea of the rules being somewhat part of the puzzle.
@TrivialHomology Thank you! Thats very kind! Though to be honest, given that this is the first puzzle I’ve ever published I am just thrilled just to see people have tried the puzzle and caught on to my idea. And all the feedback will help me improve any possible future puzzles I set!
@BigHead yes it was! One case results in a puzzle in which all the clues would have been given, but since the rules state “all clues necessarily NOT given” it rules out that possibility.
on 31. August 2026, 15:28 by miranda_9
yes @ Mozart40.The slight (sneaky) tweet in the language was the hardest.....Translation does not allways work correctly.
otherwise, nice and easy flow.
on 31. August 2026, 14:38 by TrivialHomology
I do not understand the rather low rating. I think this is a very funny twist on the usual rules, and it is communicated well enough (through the title) that there are some shenanigans going on ;)
on 31. August 2026, 10:25 by XhcnoirX
The wording of the 3rd rule is a bit awkward, I think simply stating 'Not all dots have been given' would have sufficed.
on 31. August 2026, 10:01 by miranda_9
yes @ Mozart40.The slight (sneaky) tweet in the language was the hardest.....Translation does not allways work correctly.
otherwise, nice and easy flow.
on 31. August 2026, 07:22 by BigHead
When you say "all possible dots have necessarily not been given," is that the clue to disambiguating the end? If so that's a really interesting concept and I see what you did in hindsight, but in the moment I didn't quite get it. This one's a great puzzle, I look forward to you doing another!
on 31. August 2026, 06:50 by Mozart40
I might not be able to interpret the wording of the rules 100% correctly since I’m not a native speaker and missed some nuances maybe. That meant I had to guess in the end.
on 31. August 2026, 06:44 by Bulkystapler
I could inly get to the correct solution by guessing r3c2, what is supposed to disambiguate the pairs at the end?
on 31. August 2026, 02:49 by TheAuthenticCheese
Updated Title Formatting
on 31. August 2026, 01:06 by TheAuthenticCheese
Updated HTML Formatting of Instructions
