Hollow Whispers (April Fools)
(Published on 1. April 2026, 21:46 by Lizzy01)
Happy April Fools Day!
Beware, technically logically correct rules ahead. Proceed at your own risk.
Rules:
Normal sudoku rules apply.
The lines are all a standard renban line, a standard german whisper line or a region sum line.
Thin (magenta) lines are renban lines.
On each renban line the digits form a set of consecutive digits in any order.
German whisper lines are hollow (green) and any digits which sit adjacent along a german whisper line differ by at least 5.
On thick (blue) region sum lines, each segment of the same line sums to the same total.
Box borders split region sum lines into segments.
Segments belonging to separate region sum lines do not sum to an identical total.
Play here.
You might also like these:
Small hints:
hint 2: maybe think about what the rules are NOT saying.
(slightly cryptic) hint 3: spinach is always green. apples are sometimes green. banana's can also be green but they don't taste the same as yellow banana's.
(slightly cryptic) hint 4: if i say i like blueberries, does that mean i like all berries?
Huge hint you might not want to read before thinking longer about the small hints:
Have fun solving (the rules of the) puzzle!
Solution code: Row (1 + 4)
Comments
yesterday, 13:25 by Lizzy01
You might like to check out my other puzzle Solid Whispers, and compare the way the two rulesets are written...
https://logic-masters.de/Raetselportal/Raetsel/zeigen.php?id=000SDM
on 7. April 2026, 02:20 by MathGuy_12
Brain hurty
on 4. April 2026, 15:14 by Playmaker6174
(lol I eventually got this thing done)
A funny and surprisingly nice puzzle! It took me a few attempts to fully grasp the whole trickery works behind this, since one or two lines acted like a red herring clue for me at some point, but things eventually clicked with the correct mindset at the end.
--Thank you!
on 4. April 2026, 13:12 by The Book Wyrm
Loved this puzzle. Very funny and some clever use of very careful wording. The puzzle itself was fun too - not too difficult, maybe 3* but with some nice and interesting logic.
--Thank you!
on 2. April 2026, 11:26 by juggler
I've re-read the rules at least five times, very carefully, and I still don't see any syntactic parse that makes them technically correct. There may well be one... but if so I think you might have done too good a job of making it opaque.
---
UPDATE: okay, got it after reading all of the new hints.
--
Have you actually got it, or did you get stuck again? Do let me know if you need another hint.
on 2. April 2026, 11:03 by Lizzy01
April Fools!
Read the rules carefully.
Think you've done that? Read them extra carefully.
Think you've done that too? Maybe read them again but much slower and very much extra very extremely carefully.
I may have taken this formal logic joke a bit further than is usually done on this site, but I sure hope that doesn't put you off from trying to figure it out! The actual sudoku is quite approachable once you have the rules in mind with their intended technically correct meaning.
on 2. April 2026, 00:45 by Ragna
Wrong puzzle?
--On any other day of year? Yes. On the day it was published? No. Not at all. Merely very correct rules. Hints have been added.
on 1. April 2026, 22:06 by fuxia
Can you please clarify the region sum line rule? In a standard RS line, R1C3 would be the sum of the 5 digits in box 2, which is impossible.
--Yeah that line is a big clue that some nasty trickery is going on in the rules of this April Fools puzzle, isn't it? Hints have been added.
