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Symmetry breaking

(Published on 11. November 2025, 04:53 by robertolosada)

This is my first puzzle. I tried combining as many line rules as I could while maintaining the symmetry until... it had to be broken! Hope you enjoy it!

Solve on SudokuPad

Puzzle:

1. Normal sudoku rules apply.

2. Arrows: Numbers along an arrow must sum to the number shown in the circled cell, and may (or not) be repeated along the arrow.

3. GREEN - German whispers: Adjacent numbers on this line must have a difference of 5 or greater.

4. ORANGE - Dutch whispers: Adjacent numbers on this line must have a difference of 4 or greater.

5. LIGHT ORANGE - Entropic lines: Any set of three sequential cells along this line must contain a low (1-3), middle (4-6), and a high digit (7-9).

6. TEAL - Modular line: Any set of three sequential cells along this line must contain a digit from each of the 3-modular sets (1,4,7), (2,5,8), and (3,6,9).

7. DARK-YELLOW - Nabner: Digits on this line cannot repeat, and if a digit appears, then the digits consecutive with it must not appear.

8. MAGENTA (thick) - Renban: The set of numbers on this line must be consecutive. However, they may appear in any order, and cannot be repeated.

9. GREY - Palindrome: If a number appears as the Xth cell from one end of a palindrome, it must appear as the Xth cell from the other end.

10. BLUE - Twin region sum lines: Digits have an equal sum within each box the line passes through. Both lines that appear in box 3,6 and box 4,7 have the same sum value.

11. PURPLE (thin) - Maximal Symmetric Zipper: Digits equidistant from the line's center must sum to the same value. If symmetrically extended with respect to its center on both ends (boxes 4 and 6), it breaks the zipper condition; e.g, growing the zipper line to cells r4c2 and r6c8 (its symmetric) breaks the zipper condition (r4c2+r6c8 is different than the zipper line sum value).

Solution code: Row 1, digits left to right.

Last changed on on 11. November 2025, 17:56

Solved by jalebc, jordanza, mihel111, Megalobrainiac, SKORP17
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Comments

on 11. November 2025, 22:22 by Ikke Moon
The SudokuPad links to a slightly different puzzle on the app. Plus, I'm colour-blind :-(

on 11. November 2025, 17:54 by robertolosada
Added clarification that the zipline can only be extended from its ends, which lie in boxes 4 and 6.

on 11. November 2025, 08:10 by robertolosada
It is true that the "maximal" is not necessary, but I reckon that speeds up everything considerably.

on 11. November 2025, 07:18 by jordanza
The "maximal symmetric zipper" was unnecessary. It can be solved with normal zipper in mind.

Difficulty:3
Rating:N/A
Solved:5 times
Observed:0 times
ID:000Q2T

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