Read between the lines in the FOG
(Eingestellt am 22. August 2025, 18:08 Uhr von ivaylagergova)
Normal Sudoku rules apply: Each row, column, and 3×3 box must contain the digits 1–9 exactly once.
Renban lines (pink): Digits along each line must form a set of consecutive digits, in any order, with no repeats.
German Whisper lines (green): Adjacent digits along the line must differ by at least 5.
LINES AREN'T ALLOWED TO TURN.
Quadruples: The digits in a circle indicate which numbers appear in the four surrounding cells. Digits inside quadruple circles are given in ascending order (left to right, top to bottom). There are always four distinct digits in each quadruple circle For example, if a quadruple contains the digits 2, 5, 7, and 9, the circle will display them as:
2 5
7 9
Fog of war: Parts of the grid are hidden by fog. Cells and clues are revealed as correct digits are placed.
Play online in SudokuPad.
Lösungscode: Enter the digits in Column 8 from top to bottom without spaces.
Kommentare
am 24. August 2025, 13:48 Uhr von Zibl
Really nice puzzle! :)
am 24. August 2025, 13:14 Uhr von VitP
to the setter:
i find the low quality rating unjustified.
a) you ran into the problem that some setters play shenanigans in fog cells, so that basic conventions are no longer guaranteed, and you have to explicitly STATE things that might seem "obvious" to you.
b) sure, some rules clarifications were needed, but that should be handled by errata, not down-rating the puzzle and running away. but be aware that on this site, there is a strong random component to the ratings people give.
c) generally speaking, this is a fine puzzle
am 24. August 2025, 04:03 Uhr von VitP
the errata that the quad digits do NOT repeat needs to be incorporated directly into the rules.
Furthermore, you need to make clear that there are no shenanigans when a renban enters a fog cell from 2 sides. Is that one continuous line? there is no convention, so you need to state your choice.
now, aside from these rules clarifications, i found this puzzle "intractable" ... because i overlooked the fog clearance in box 7. once i paid proper attention to such things, i found that the puzzle solves fairly easily.
administrative note: i recommend shading the entire grid YELLOW before starting the solve, otherwise it will be too hard to see the candidates.
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Thanks a lot for pointing this out! You’re absolutely right – I should have made it clear in the rules that quadruple digits don’t repeat, and that a Renban entering a fogged cell from two sides is still considered a continuous line. I’ll edit the description to avoid confusion. Glad you enjoyed the puzzle once the fog detail clicked! :)
am 24. August 2025, 00:08 Uhr von rdesmarais2
2* for me. Different concept but not overly difficult.
am 23. August 2025, 10:20 Uhr von jinkela114514
Can different lines share cells?
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Only lines of different types may share a cell.
am 23. August 2025, 08:22 Uhr von ivaylagergova
Description updated!
am 23. August 2025, 08:17 Uhr von ivaylagergova
Updaded!
am 23. August 2025, 02:09 Uhr von B2Belts
I'm stuck. Maybe I'm missing something really obvious but it feels like the Sudoku wants me to assume that there are 2 Renbans in row 3 (which would solve r3c5 and r4c5) when it could just as easily be one continuous Renban spanning the whole of row3.
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Thank you for the comment! You can try now the updated version.
am 23. August 2025, 01:04 Uhr von StevenS
I'm stuck. Are lines allowed to turn?
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Good spot! Thank you! I've added an extra constraint in the rules.
Lines aren't allowed to turn.
You can try now the updated version.
am 22. August 2025, 22:11 Uhr von rinvel0
It was a delight. It turns you around in circles. Circle is your friend! Be with the circle! :)
am 22. August 2025, 21:36 Uhr von ivaylagergova
Updated rules in SudokuPad.
am 22. August 2025, 20:58 Uhr von isajo4002
I feel like the rules could use a bit more polishing because I feel like the rules are a bit ambiguous like the quadruples don't say that they are distinct rules and I feel like i am supposed to make a few assumptions to break into the puzzle
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Thank you for the feedback! The rules are updated.
am 22. August 2025, 20:42 Uhr von ivaylagergova
Quadruples expampe given.
am 22. August 2025, 20:31 Uhr von Philologos
These might be silly questions, but I cannot really tell what I can assume, sorry.
First, can I assume that digits in a quadruple are always 4 and always different from one another?
Second, can I assume anything regarding the Renbans e.g. can I assume that the line in row 3 is divided in two and not just one long line? I see no reason why I can exclude that this line can literally take all 9 cells of the row, much like the one in box 4 could take all cells in box 4, making them both pleonastic since the same constraints are given by Sudoku.
Of course, I could just be missing something, and the fog would reveal something. However, I really cannot tell how to proceed without using the Renbans, and I seem to be getting nothing from them, so I just want to make sure I am not missing some fog-related assumptions. Sorry for the wall of text.
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There are always four distinct digits in each quadruple circle. The digits are written in ascending order, arranged from left to right and then from top to bottom. For example, if a quadruple contains the digits 2, 5, 7, and 9, the circle will display them as:
2 5
7 9
I hope this helps you make your first move. :)
am 22. August 2025, 18:59 Uhr von Myfyr MJ
Nice puzzle but very hard. I think I might have got lucky in the solve.
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Thank you! Can you rate it?
