Logic Masters Deutschland e.V.

Four Past Ninety

(Published on 26. July 2026, 21:05 by Muhammad)

This is my first hard puzzle, inspired by Neokart's puzzle "Nine in the Afternoon".

Rules
  • Normal Sudoku Rules: Each row, column, and 3×3 box must contain the digits 1–9 exactly once.

  • Killer Cages: The digits within each cage must sum to the clue shown in the cage's top-left corner. Digits may not repeat within a cage.

  • Arrows: The digits along an arrow must sum to the digit in the connected circle or the number in the connected pill. Numbers in pills are read from left to right or from top to bottom. Digits may repeat along an arrow if permitted by the other rules.

  • Palindrome: Digits on a thick gray line form a palindrome; they read the same forwards and backwards.

  • Region Sum Lines: The borders of the 3×3 boxes divide each blue line into segments with equal sums.

  • Black Dots: Digits connected by a black dot are in a 1:2 ratio.

  • White Dots: Digits connected by a white dot are consecutive.
A small note for solvers:
The first break-in is a key to the second.
What you learn from the first will make something possible that wasn't possible before.
▶ Solve on SudokuPad
Enjoy solving!

Solution code: Row 5

Last changed on on 27. August 2026, 14:45
Solved by SKORP17, jmw, StefanSch, jalebc, Da Letter El, strangelyinsane, Snookerfan, Arheus, mezkur7, Zzzzz..., snowbaby, finger, Maxius, han233ing, Megalobrainiac, kangaroo
Full list

Comments

on 21. August 2026, 18:27 by Muhammad
Added a small note to clarify the intended two-stage break-in.

Last changed on 3. August 2026, 08:20

on 28. July 2026, 22:41 by Arheus
A solid 5*. I am very proud to have gotten the first step, I still don't know what the second step was unfortunately, spent a long time poking in the dark. Very original, loved it

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Hi Arheus,

Thank you! I'm really glad you enjoyed it, and I'm happy you found the first step.

The intended second step is actually described in detail in jmw's hidden comment if you're interested. He did a fantastic job explaining the SET process, and I added a couple of small notes in my reply as well.

Thanks again for solving and for the kind words, they mean a lot!

Last changed on 3. August 2026, 13:36

on 28. July 2026, 11:27 by Snookerfan
Brilliant puzzle! The break-in was amazing, the next steps were so tricky, that I must have missed something. Thanks

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Hi Snookerfan,

Thank you! I'm really glad you enjoyed it.

You didn't actually miss anything major, the intended second step is quite intricate. jmw has posted a hidden comment with the intended SET path, if you're interested in seeing how it unfolds.

Thanks again for solving and for the kind words!

on 28. July 2026, 01:25 by jmw
What a brilliant puzzle. Without wanting to give anything away, the break-in is cool, but it's the fact that the second step works with the same grid that blows my tiny mind. I have no idea how you managed to work that in.

on 26. July 2026, 22:59 by Muhammad
Solution code added

on 26. July 2026, 21:37 by jalebc
code?

Difficulty:5
Rating:N/A
Solved:16 times
Observed:2 times
ID:000U2B
Sudoku, Kropki, Killer (Variant), Arrows (Variant), Palindrome (Variant), Region Sum Lines (Variant)

Enter solution

Solution code:

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