Rotationally Symmetric Constraints No. 2
(Published on 4. March 2026, 21:11 by RailMan)
Normal sudoku rules apply. Place the digits 1 - 9 once in every row, column and box.
Palindrome: The grey line is a palindrome and must read the same from both ends.
Kropki Dots: Digits separated by a white dot are consecutive. Digits separated by a black dot are in a 1:2 ratio. Not all dots are given.
Maximum: The digit on the grey square with arrows pointing outwards is larger than all orthogonally adjacent digits.
Rotational Sums of 10: All digits in the grid have a 180 degree rotational opposite. Every digit and its rotational opposite add to 10. Eg. R1C2 and R9C8 must add to 10. Eg. R5C4 and R5C6 must add to 10.
Solve Online : Solution Check is enabled
Try some of my other puzzles using Rotational Symmetry here:
Solution code: Row 9
Comments
on 7. March 2026, 01:50 by wunder108
Its a very interesting break in! I just don't appreciate your comment giving away some hints. If you create this logic to be solved doesn't make sense to give it away.
RailMan: Thank you for your feedback. People are welcome to solve it without using the hints if they want to. But when I see that very few people are solving it then I sometimes think a hint might be useful.
on 5. March 2026, 13:44 by RailMan
This is a difficult puzzle so I will put a hint below. Spoiler warning!
The palindrome causes roping on the bottom three rows. The rotational symmetry then causes roping on the top 3 rows.
The kropki dots on rows 1&2 can be reflected to rows 8&9 because of the rotational symmetry.
Then you can find the break-in using the roping and kropki dots in boxes 8 & 9. Good luck and have fun.
on 5. March 2026, 10:09 by Grendpeppy
Several points at the start where I was baffled that there was a solution, but eventually after resorting to brute force on the box where I assume the break-in is intended, the rest of the solve flowed nicely. Great puzzle!
RailMan: Thank you. This is a difficult puzzle. There is an interesting logical break-in, but it has several steps before you can place any digits.
