Follow the Five Brick Road
(Published on 21. May 2025, 23:54 by EnPee)
I hope you enjoy solving it!
Rules
Normal Sudoku rules apply. In this puzzle, each cell's VALUE is equal to its digit modulo 5 (note that 5 has a value of 0 so is not consecutive with 4).
Dynamic Fog: The grid is partially covered with fog. A correctly placed digit will clear the fog from that cell and may clear fog from other cells. No guessing is required.
Kropki: VALUES separated by a white dot are consecutive. VALUES separated by a black dot are in a 1:2 ratio. Not all dots are shown.
Killer: VALUES in a cage cannot repeat and their sum modulo 5 is the number in the top left corner of the cage (if given).
Renban: VALUES on a purple line form a non-repeating set of consecutive VALUES in any order.
Mystery Constraint: This will be revealed under the fog and does not depend on values modulo 5.
If anyone is not familiar with the mystery constraint, feel free to DM me on Discord and I'm happy to explain (@Enpee on the CTC Discord server)
Solution code: Column 5
Comments
on 17. August 2025, 14:53 by MattYDdraig
Nice puzzle. Reasonably simple, but the mystery of how mod 5 will unravel is beautifully solved at the end.
on 29. May 2025, 06:29 by Freegerator
Loved this one, thank you!
- Thank you, glad you enjoyed it!
on 24. May 2025, 20:48 by Galc127
Amazing construction, took me a lot longer than expected.
Thanks for a beautiful puzzle.
on 24. May 2025, 20:48 by Galc127
Amazing construction, took me a lot longer than expected.
Thanks for a beautiful puzzle.
on 24. May 2025, 19:14 by PjoeterBliep
Would a 3 and 1 be allowed to be on a black dot? Because 3×2 = 1 (mod 5)?
- Thanks for solving! You'll have worked out it's not allowed - it's the values mod 5 that have to be in a 1:2 ratio. This came up in testing too - that rule probably isn't mathematically pure but since it was the first piece of logic I created decided to leave it in! Hope you enjoyed the puzzle :)
on 23. May 2025, 16:37 by Galc127
Amazing construction, took me a lot longer than expected.
Thanks for a beautiful puzzle.
- Thank you for the kind comment, glad you enjoyed it!
on 22. May 2025, 20:41 by dzamie
Oh wow, this is really incredible! I was wondering how we'd go from the mod-5 rule to actual digits, and I really didn't expect it to actually work when I first saw it.
But once you start placing non-5 digits, it feels like a very well-deserved victory lap. Great use of dynamic fog, and really creative rules!
- Thank you very much, it also felt like a victory lap when I found it worked!
on 22. May 2025, 20:09 by Exigus
Just under an hour. Very cool variant, thanks!
- Glad you enjoyed it :)
on 22. May 2025, 16:50 by VitP
awhooo, werewolves of box 5, awhooo.
if you solve this sudoku, (and you know warren zevon), you will agree ... when you get there.
WARNING: you need a PhD in mathematics to even START this puzzle.
why? because, for PRACTICAL reasons, you will FIRST need to develop the mathematical rules that apply in the mod 5 VALUE-space, from scratch, and only mathematicians will even know what those words mean, and WHY they are true.
here are the first 2 rules:
0) the NEW "secret" is zero.
1) S = {0,1,1,2,2,3,3,4,4}
- Had a good chuckle at your comment, thanks for solving!
on 22. May 2025, 16:40 by kublai
Amazing! Once I twisted my brain around the mod 5 ruleset, it unlocked pretty easily. Thank you for setting.
- Thank you for solving, glad you enjoyed it!
