Foggy entropy
(Published on 19. August 2025, 14:58 by ivaylagergova)
Difference Kropki dots (white): Cells joined by a white dot must have a difference of 1. Not all dots are given.
Ratio Kropki dots (black): Cells joined by a black dot must have a ratio of 2. Not all dots are given.
X clues: An "X" between two cells means they sum to 10. Not all X clues are given.
German whisper lines (green): Adjacent digits along a line must differ by at least 5.
Global entropy: Each 2×2 region of cells must contain at least one digit from each of the three categories:
– Low (1, 2, 3)
– Medium (4, 5, 6)
– High (7, 8, 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
Solution code: Enter the digits in Row 9 from left to right without spaces.
Comments
on 24. September 2025, 09:13 by ForzaFcu
Amazing puzzle. was challenging till the end
on 30. August 2025, 10:19 by ivaylagergova
updated
on 23. August 2025, 17:36 by ivaylagergova
To be honest, this was my first attempt at creating both a fog puzzle and an entropy puzzle. I just had an idea for the opening and decided to give it a try. I’m really glad you enjoyed it.
on 23. August 2025, 05:57 by NorthCoastAsher
This was my first fog puzzle, and it was very enjoyable! It took me some time due to learning the constraints, but was still an enjoyable puzzle and not annoying.
on 20. August 2025, 11:38 by BaumiB
First time doing this kind of sudoku. Took me over 45 min but managed to solve it! Was lovely! Thanks so much
on 20. August 2025, 05:14 by Nitrobit
I really liked the ending
on 19. August 2025, 21:22 by ivaylagergova
Thank you for your feedback!
All of the puzzles I create are originally designed for my students as part of my extra math lessons at school, where we explore a wide variety of logical challenges.
In this sudoku, I’ve included seven additional constraints to make it more approachable and engaging.
on 19. August 2025, 20:44 by sujoyku
Thank you for the fun puzzle, ivaylagergova!
