Erica 20 (Antiknight Fog Edition)
(Published on 30. November 2025, 17:15 by SennyK)
Today's Erica has a lot in common with chess knight :-)
I hope you will enjoy and I would be really grateful for all the comments and ratings.
Normal sudoku rules apply.
Fog: The grid is partially covered in fog. Entering correct digit will clear fog from its cell and all cells knight's move away (in chess). No guessing is required.
Antiknight: Cells seperated by a knight’s move (in chess) cannot have the same digit.
German whisper: Neighbouring/adjacent digits along a green line have a difference of at least 5.
X/V: Digits in cells joined by an X sum to 10. Digits in cells joined by a V sum to 5. Not all Xs and Vs are given.
Antiknight Explanation:
You can imagine that digit 1 is a chess knight. Each cell accessible to it via a knight's move (in chess) cannot contain another 1.
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: Third (3rd) column of the grid from top to bottom.
Comments
on 27. March 2026, 17:33 by vulaplaya
Really fun puzzle thanks SennyK. I’m enjoying your Erica series.
And thanks VitP for the colouring tip which got me out of some sticky situations.
on 16. December 2025, 22:02 by Myfyr MJ
Very nice, thank you.
on 2. December 2025, 22:13 by 3ffer
Loved it, but 2* at the most.
on 1. December 2025, 02:03 by VitP
a couple people in the comments seem to be unfamiliar with how pair colouring works.
There will be a number of cells where you have a PAIR of candidates, eg. {23}. label one of them red, say, and the other green (good contrast). propagate that colouring around the grid. you will find a cell with candidates {123} that "sees" both red and green, and therefore must be 1. later, do the same thing with the {79} pair.
on 30. November 2025, 23:40 by galium_odoratum
2.5* for me as well. Fun puzzle with a challenging endgame.
on 30. November 2025, 22:19 by Martina
Nice! 2.5* or 3* for me.
on 30. November 2025, 21:19 by VitP
pair colouring, which is not quite a basic technique (but it COULD be) features strongly in this puzzle
on 30. November 2025, 21:00 by s1mn
Love it!
on 30. November 2025, 20:27 by wuc
Great fun steps almost till the end. Some harder viewing ideas in the end makes it rather 2.5* to me. Great setting thx.
on 30. November 2025, 19:24 by hardline35
very enjoyable fog puzzle. thank you!
