Purple Lines
(Published on 16. January 2026, 13:46 by Wiggel)
This puzzle is a bit of a strange one, inspired by some of juggler's puzzles.
I hope you enjoy the journey.
Thanks to curlingclips for giving me the idea for this puzzle and for helping with some details.
Rules:
- Normal sudoku rules apply: Place the digits 1 to 9 once each, in every row, column and box.
- The grid is covered in fog, placing correct digits clears the fog somewhere in the grid.
No guessing is required, of course.
- Blue lines are Modular Lines, every connected run of 3 cells along them must contain one digit each from each modular set [147 258 369].
- Red lines are Parity Lines, when going along them, digits alternate between odd and even.
- Purple lines, ... - What? The title mentions purple lines?
What were they again? Maybe they were Renbans?
The digits on a Renban form a set of consecutive, non-repeating digits in any order.
- No, that was wrong! No purple line could ever be a valid Renban.
Ah, now I remember! They just combine the rules of the other two lines.
So a purple line is always a valid blue line and a valid red line.
At the same time! Good thing I remembered that.
- Now that I'm done explaining the rules, I have to get going.
I really hope the rules will help you with solving the puzzle.
Solution code: Row 1 (left to right)
Comments
on 17. January 2026, 02:07 by Zpixi09
stellar fog puzzle, didnt even notice what was happening until the fog fully cleared
on 16. January 2026, 22:15 by Gullie
Truly one of the funniest and sneakiest fog puzzles I’ve dver done. Very nice!!
on 16. January 2026, 21:51 by keenbowl
Lovely puzzle
on 16. January 2026, 21:33 by sujoyku
What a fun idea! Thank you, Wiggel!
on 16. January 2026, 21:30 by packt
Wow... i only noticed the trick by the very end, and then another one struck me hidden in plain sight! as someone who started doing sudoku only 2 months ago, this is now my favorite solved one :)
on 16. January 2026, 20:01 by Zelfie
Lovely puzzle and amazing flow... really loved the ruleset!
on 16. January 2026, 19:45 by hige
wow wow wow
i did not realize it happening at all
hint: read the rules just as far as you need to! ;)
on 16. January 2026, 19:32 by abihummel
Absolutely amazing! It took me so long to figure out what was going on. I almost want to re-solve it now knowing what to look for! Between this and "Hazy Radio Tower," you have cracked the code on fascinating fog variants. Keep them coming!!!
on 16. January 2026, 19:00 by Shearing
Same here. In the end I had to read the rules four times for it to click. Great puzzle!
on 16. January 2026, 18:55 by balpha
I was about to post exactly the same comment as Bussibaer, but after reading your response, I read the rules again ... and again ... and again ... and I finally saw it. Very sneaky, well played :D
This was fun!
on 16. January 2026, 18:52 by superkinkel
This is absolutely gorgeous. No spoiler here, but let's say, if you like fog of war, here is something happening that makes it fog squared!
Couldn't believe my eyes and thought there was a display defect first.
And - to drop a small hint - if you're stuck with disambiguating the final digit pair: Reread the rules very thoroughly, the clue is easy to miss.
Either way: This is one of the most remarkable puzzles I've seen and certainly one you will never forget.
on 16. January 2026, 17:53 by Adrian71
That was quite an experience! Fun puzzle, thanks!
on 16. January 2026, 14:09 by Manta-Ray
That was incredible! I have no idea how you did that effect, but I'd sure love to know :D
