Logic Masters Deutschland e.V.

What the Fog?

(Published on 16. November 2025, 17:15 by SennyK)

What the Fog?

Another puzzle for those who love dynamic fog of war sudoku! :-)

Disclaimer: you need to fill in all possible logically deduced digits before new constraints will be revealed, so you will have to do some sudoku ;-)

I hope you will enjoy and I would be really grateful for all the comments and ratings.

Normal sudoku rules apply.

Dynamic fog: The grid is partially covered in fog. Entering correct digits may clear fog somewhere in the grid. No guessing is required.

Arrow: Digits along an arrow sum to the number in the attached 2-cell pill read from left to right.

Thermometer: Digits along a grey thermometer increase from bulb to tip.

Kropki dots: Digits in cells joined by a white dot are consecutive. Digits in cells joined by a black dot are in a 1:2 ratio (i.e., one digit will be double the other). Not all dots are given.

X: Digits in cells joined by an X sum to 10. Not all Xs are given.

German whisper: Neighbouring/adjacent digits along a green line have a difference of at least 5.

Killer: Digits in a cage sum to the total given.

Region sum line: Box borders divide a blue line into segments which have the same sum.

SudokuPad Link

If you liked this puzzle, I recommend trying out my other puzzles:

The Erica Series:
☆☆☆☆: 1, 2, 4, 5, 6, 12, 15, 17, 23, 26, 27
★★☆☆☆: 3, 7, 8, 10, 11, 13, 14, 16, 18, 20, 24, 25
★★★☆☆: 9, 19, 21, 22

Shading/Ying-Yang:
★★☆☆☆: Pretty Odd Shaded Area
★★★☆☆: (+5)-Yang, Negative 8 YY
★★★★★: Why-Why?

Fog of War:
☆☆☆☆: Erica 12, Erica 17
★★☆☆☆: It's What You Do in the Dark That Puts You in the Light, Find It All, What the Fog?, Erica 20
★★★☆☆: Broken Flashlight in the Dark

Pencil Puzzle/Sudoku Hybrid:
★★☆☆☆: Masyu (Short) Sudoku
★★★☆☆: Tetromino Sudoku

Various Puzzles:
☆☆☆☆: Blown Fuses in Electrical Installation, Let Me Introduce Myself, French Wrench
★★☆☆☆: Symmetrical Fan, Night Club, Important Hour on the Clock, What Was the Sum Again?, Disgroup Joints, 10-Arrows, Antiking Dutch Skyscrapers
★★★☆☆: Cops & Robbers, Positive Symmetry, Doppelgänger Killer 1-25
★★★★: Liars. Liars Everywhere.

Solution code: Ninth (9th) column of the grid from top to bottom.

Last changed on on 12. December 2025, 23:26

Solved by fuxia, Nickyo, BULL-TT, Harold, lingbincc, anthe95, maglia, xrrx, Blaimi, SudokuFan, walid_tun, flaemmchen, Joven, nunc, Jayem, RebelSystem, johnreid, GorgeousNicko, Crul, weiken, TripleABattery, ... zenas777, doomedmageknight, jorgenunez, oddwheel, AlexRaetselt, DaFunkyMonk, philolologue, fergus, timww572, jackiez33, tifuuu, luisdcnt, superkinkel, OJPS, cqq, ApellA, pfox, katze, Nosferatu
Full list

Comments

on 17. December 2025, 20:51 by philolologue
Def got stuck for a few minutes on the logic in the bottom of box 7, but felt so rewarding when I figured it out! Just a few seconds under half an hour for me, so much fun!

on 18. November 2025, 01:48 by dzamie
Very fun! I appreciate that there was never a point where you simply revealed all the tiles; it can feel like a bit of a flashbang when a setter does that. This flowed really well, and I never found myself stuck or wondering where next to focus.

on 17. November 2025, 19:33 by Cantabrigiensis
Excellent puzzle, thank you.

on 17. November 2025, 14:32 by VitP
how dare you require us to do sudoku

- simon sez

on 17. November 2025, 13:52 by Myfyr MJ
Very nice, dynamic fog tricky (as usual).

on 17. November 2025, 08:21 by grrz
Clever interconnected clues, a pure joy. Thank you!

on 17. November 2025, 02:39 by Cyprane
Thank you. It was very educational.

on 16. November 2025, 23:19 by hardline35
Very enjoyable fog puzzle. Thank you!

on 16. November 2025, 22:49 by wentel21
Lovely 2* puzzle! Thx <3

on 16. November 2025, 22:16 by wuc
Great fog ideas. One harder step mid solve leads to 2*. Rest easier. Great fun thx.

on 16. November 2025, 20:43 by Pairot
Great puzzle. Really making me work for the fog!

on 16. November 2025, 18:34 by nunc
That was a fun one. I liked the "constraint" that you have to find all deductions before another part of the fog lifted. Well done, thanks a lot.

Difficulty:2
Rating:92 %
Solved:298 times
Observed:0 times
ID:000Q4I

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Solution code:

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