No Knights in the Foggy Field of Emeralds and Sapphires
(Published on 24. July 2026, 19:26 by Merdock)
Puzzle Links:
Click here to solve the standard version of this puzzle.
Click here to solve the harder version of this puzzle.
Note on difficulty
I am providing two different links for this puzzle, and the only difference is one clue. The picture above is of the harder version, as this clue is visible from the start of the standard version.
I think the first one borders on 3-4*, and the second has a deduction that I think stands out, in terms of difficulty, from the others. This deduction was so much harder and less intuitive than the others that I decided to include a clue for the standard version to bypass that deduction. I'm hoping that clue will make the puzzle more enjoyable to solve. I also decided to include a link to the version without this clue, for anyone who wants to take a crack at it.
If you play the harder version of this puzzle, can you please make a comment to help others decide which version to tackle for themselves?
Rules:
Regular sudoku rules:
Place the digits 1-9 in every row, column, and box
Anti-Knight:
Cells that are a knight's move (in chess) apart must not contain the same digit.
Region Sum Lines:
Box borders divide each blue line into segments with the same sum.
German Whisper Lines:
Adjacent digits along green must differ by at least 5. These lines have a smaller white line inside them, giving them a hallow appearance to help distinguish between the types of lines.
Grey Circles:
Cells with a grey circle must contain an odd digit
Killer Cages:
Digits in cages must sum to the number in the upper left corner of the cage.
Black Kropki Dots:
Black Dots separate digits that have a ratio of 2:1. Not all dots are given
Solution code: Digits in box 2, read left to right and top to bottom (r1c4, r1c5, r1c6, r2c4...)
Comments
on 26. July 2026, 21:43 by Gunkan
Solved the harder version, got stuck half way for some reason, but somehow found the way forward, or rather somehow missed it for almost an hour
on 26. July 2026, 12:08 by Dr Logic
Interesting break in, I solved the harder version and found it ~3 stars. Nicely set :)
on 25. July 2026, 15:39 by Redmuunk
I solved the hard version, but it was very difficult, 4* for me. Not sure how the standard version would be any easier.
Merdock: I just took a second look at it and I found a less convoluted way to find the digit the clue is supposed to assist you with, so it's very possibly to look at the clue I provided and say "what's that doing there. I would still say the method that involves the clue still seems the easiest out of all of them, but there could be yet another method I'm not seeing. If you want a more spoiler-filled discussion of it, you can email me at sudoku.merdock@gmail.com
on 25. July 2026, 14:22 by Katchoo
I love Merdock's puzzles. They are simply special. I did the difficult version, and the deductions all fit.
Merdock: Thank you so much Katchoo, I really appreciate it!
on 25. July 2026, 11:22 by amirs
I tried the harder version of the puzzle and it was indeed very hard and required a series of non-trivial yet satisfying deductions.
on 25. July 2026, 09:58 by AlexT74_NL
The break-in was a really nice find. It took me a while, but I finally cracked the harder version. Nice one!
on 24. July 2026, 20:57 by Merdock
Updated tags
on 24. July 2026, 20:46 by Merdock
Changed difficulty to 3*
