Logic Masters Deutschland e.V.

Entropic Reflections

(Published on 14. October 2025, 10:00 by sujoyku)

My friend Calvinball has redeemed a Setting Saturday prompt asking to set around the theme of reflections. I have gone for mirrored entropic groups and hope it is an approachable and fun puzzle. I am thanking all testers and wish you joyful solving!

Rules:

- Normal sudoku rules apply, i.e. each row, column, and 3x3 region has to contain the digits from 1 to 9 once each.

- Entropy Mirror: The diagonal from r1c1 to r9c9 acts as an entropy mirror. Each cell has the same entropy as the cell reflected in the mirror, i.e. if r2c6 contains a low digit (from 123), then r6c2 must also have a low digit.

The remaining rules are standard. Feel free to skip them if you are familiar with XV, Kropki, GW and Arrows.

- XV: Digits joined by an X sum to 10. Digits joined by a V sum to 5. (Not all XV are given.)

- Kropki: Digits joined by a black dot have a 1:2 ratio. Digits joined by a white dot are consecutive. (Not all dots are given.)

- German Whispers: Adjacent digits on a green line must have a difference of at least 5.

- Arrows: Digits on an arrow sum to the digit in the circle from which the arrow emerges.

Here you can solve the puzzle online:

Solve on Sudokupad

Solution code: Column 9 from top to bottom (9 digits in total)

Last changed on -

Solved by Silentdodo, benisjammin, Luaryo, Imagio, damo_89, wuc, jalebc, ludvigr04, Krisonium, salsais, ChinStrap, tuturitu, palpot, Merovius, Calvinball, Snuggles, Photyne, jordanza, Flinty, RebelSystem, ... timww572, Lenivaya_Joppa, Bazylizz, OGRussHood, SpecSheets, Arlo Lipof, flipout, DarkPaladin, darkgently, TeddieMilo, CSStead, Leodesian, Uhu, woody, Malakree, cascadeshiker, erkiraak, silent_rob
Full list

Comments

Last changed on 27. November 2025, 18:49

on 27. November 2025, 02:47 by silent_rob
Great puzzle, lots of fun to solve. I really enjoyed the entropic mirror constraint. Thanks, sujoyju!

**
Thank you for your comment, silent_rob! It is great to hear you enjoyed the Entropic Mirror constraint.
Kind regards, sujoyku

Last changed on 9. November 2025, 20:15

on 9. November 2025, 16:40 by Lenivaya_Joppa
Thank you for this very nice puzzle, dear sujoyku! :)

**
Thank you for your comment, Lenivaya_Joppa! It is great to hear that you liked it.
Kind regards, sujoyku

Last changed on 28. October 2025, 19:51

on 28. October 2025, 05:58 by tptruss
great puzzle! though i'm curious whether adding a diagonal rule could pair well with this...

**
Thank you, tptruss! I am glad that you liked the puzzle. I think it could work well with a diagonal constraint. I actually experimented with it shortly and am planning to come back to that for another mirror puzzle.
Kind regards, sujoyku

Last changed on 15. October 2025, 16:38

on 15. October 2025, 05:05 by collin525
Very fun, approachable, and well set!

**
Thank you, collin525! It is great to hear you enjoyed it.
Kind regards, sujoyku

Last changed on 15. October 2025, 16:37

on 15. October 2025, 04:03 by majestic spork
Lovely puzzle! Fun new rule.

**
Thank you, majestic spork! I am glad you liked the ruleset.
Kind regards, sujoyku

Last changed on 15. October 2025, 02:43

on 15. October 2025, 02:18 by antiknight
Cool break-in

**
Thank you, antiknight!
Kind regards, sujoyku

Last changed on 15. October 2025, 01:55

on 15. October 2025, 01:08 by Killer Joe
I really liked the break in and the reflections in the central boxes. Very cool. Thanks for the puzzle and some fresh inspiration perhaps.

**
You are much welcome, Killer Joe, thank you for your comment! I am glad that you liked it. And if you feel inspired, please do play with this variant. I would love to see more Entropy Mirror puzzles.
Kind regards, sujoyku

Last changed on 14. October 2025, 23:29

on 14. October 2025, 23:12 by Sez
I'd like to see more of this ruleset, it was very fun!

**
Thank you for your comment, Sez! I am glad you liked this ruleset.
Kind regards, sujoyku

Last changed on 14. October 2025, 17:31

on 14. October 2025, 17:13 by Ragna
Fun puzzle! Thank you, sujoyku :-)

**
Thank you for your comment, Ragna! It is good to hear you had a fun solve.
Kind regards, sujoyku

Last changed on 14. October 2025, 17:30

on 14. October 2025, 16:26 by Olive
Great puzzle! Thank you

**
You are much welcome, Olive! I am glad you enjoyed it.
Kind regards, sujoyku

Last changed on 14. October 2025, 15:39

on 14. October 2025, 15:06 by Myfyr MJ
Fun, challenging puzzle - 45 minutes approximately! Thanks.

**
Thank you for your comment, Myfyr MJ! I am glad you had a fun solve.
Kind regards, sujoyku

Last changed on 14. October 2025, 13:39

on 14. October 2025, 13:32 by Calvinball
Exactly the kind of puzzle I was hoping to solve, thanks sujoyku!

**
Superb to hear you liked it, Calvinball! It was so much fun to set for your prompt.
Kind regards, sujoyku

Last changed on 14. October 2025, 13:08

on 14. October 2025, 13:00 by ChinStrap
Very lovely setup with fun questions to ask

**
Thank you for your comment, ChinStrap! I am glad you enjoyed it.
Kind regards, sujoyku

Last changed on 14. October 2025, 11:54

on 14. October 2025, 11:21 by wuc
Cool 2* snack with a lovely refreshing ruleset. Great setting thx.

**
You are much welcome, wuc! I am glad that you enjoyed this variant.
Kind regards, sujoyku

Difficulty:2
Rating:97 %
Solved:211 times
Observed:2 times
ID:000POM

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Solution code:

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