Mostly Harmless: Know where your towel is
(Published on 17. April 2026, 02:11 by AaronH)
“What the strag will think is that any man that can hitch the length and breadth of the Galaxy, rough it, slum it, struggle against terrible odds, win through and still know where his towel is, is clearly a man to be reckoned with.” - The Hitch Hiker's Guide to the Galaxy
Rules
Normal sudoku rules apply: fill the grid with digits 1–9 so that no digit repeats in any row, column, or 3×3 box.
All variant clues follow their standard meanings; full descriptions are provided below.
- Dynamic Fog: The grid is covered with fog; entering correct digits may clear fog elsewhere, and no guessing is required. Any lines or markings continue and connect beneath fog. Unless revealed, no additional clues should be assumed to exist under the fog.
- Diagonal Lines: Along each indicated diagonal line, the digits 1–9 must appear exactly once.
- Kropki Dots: A black dot indicates one digit is exactly double the other.
- X / V Sums: An X between orthogonally adjacent cells indicates the digits sum to 10, and a V indicates the digits sum to 5.
- German Whispers: Along a green line, adjacent digits differ by at least 5.
- Entropic Line: Along a peach line, any three adjacent digits must include one low digit {1,2,3}, one medium digit {4,5,6}, and one high digit {7,8,9}.
- Nabner Line: A yellow line cannot contain two digits anywhere on the line that are consecutive.
- Arrows: The value of digits along an arrow must sum to the number in the corresponding circle/pill. Two-cell 'pills' are all read from left to right.
- Don’t Panic!: No guessing is required - you are one hoopy frood.
Primary Phase
- Fit the First - Mostly Harmless
- Fit the Second - Mostly Harmless: Know where your towel is <-- You are here
- Fit the Third - Mostly Harmless: Zaphod Beeblebrox
- Fit the Fourth - Coming soon...
Solution code: Row 6 - left to right
Comments
on 22. April 2026, 09:51 by snuuba
Rating this as 1 stars is just bonkers. 1 star would imply that average person would be able to solve this without knowledge of special variant sudoku theorems. To solve this one you will have to know at least two of them. Nice puzzle though and fairly easy if know what to look for.
on 21. April 2026, 07:43 by JVA
Getting Box 4 to show up is 2*, therefore 2*
on 20. April 2026, 20:49 by Anthony
I found this to be quite easy, easier than some other commenters seem to. My biggest rules in fog of war sudokus is that if I feel stuck, I immediately switch to plain sudoku. This rule of thumb has not failed me yet!
on 20. April 2026, 16:32 by faltenin
Quite the Gargleblaster. Thanks!
on 19. April 2026, 10:12 by sujoyku
There was a moment in which I felt quite lost. Luckily, the last rule came to my rescue: Not only did it tell me not to panic, but also reminded me that I was a hoopy frood after all which gave me all the strength needed for the rest of the puzzle. I absolutely love the Hitchhiker's Guide and your puzzle series brings back so many fond memories. Thank you, AaronH!
on 18. April 2026, 13:09 by QuozBat
Don't think I'd call the middle 1-star. I'm quite lost on what to do after r5c5 is revealed.
on 18. April 2026, 12:17 by Jen118266
I very much enjoyed this puzzle. Thank you
on 18. April 2026, 05:03 by Karitsu
Mostly 1*, with a pretty tough spot right in the middle there.
on 18. April 2026, 04:48 by BorisTheSnake
Excellent and easy way for others to understand The "standard variant rules." Very nice :)
on 18. April 2026, 03:47 by SanFranSam
But he had misplaced his earplugs. ;)
on 17. April 2026, 16:01 by superkinkel
Probably only a single star, but love the Hitchhiker's guide theme!
on 17. April 2026, 11:50 by Martina
Very enjoyable. 1* for me.
on 17. April 2026, 11:38 by Cassinii
Brilliant puzzle. Fog of War is easily one of my favourite constraints, thanks for sharing!
on 17. April 2026, 11:11 by VitP
rules omission:
you need to explicitly state that a line that enters a fog cell from multiple directions CONNECTS.
(this is not the default condition, as it has been done the other way enough times to create precedent)
anyway, this solves very easily using standard procedures. the fogon threat has known solutions, just don't panic.
--> level 1
AaronH: Good catch, thanks. I’ll update the rules to clarify that.
