Erica 21 (Phistomefel Ring Edition)
(Published on 4. December 2025, 17:15 by SennyK)
You will need to notice tricky things to solve today's Erica :-)
I hope you will enjoy and I would be really grateful for all the comments and ratings.
Normal sudoku rules apply.
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.
If you liked this puzzle, I recommend trying out my other puzzles :-)Solution code: Ninth (9th) row of the grid from left to right.
Comments
on 25. May 2026, 18:02 by Reina
I understand the principle of Phistomefel Ring but cannot use it to solve. Luckily it is not required.
on 16. January 2026, 09:36 by sunevora
Could not see how the Mephistophel Ring gives any advantage here.
on 6. December 2025, 16:07 by Ste1729
This puzzle is probably 1* if you're familiar with Phistomefel ring, but it's 3* otherwise.
I didn't know about Phistomefel ring, and I started solving normally. After around 1 hour, (I had only placed 8 digits) one of my friends joined me, told me that rule and together we finished the sudoku in just 10 minutes.
on 6. December 2025, 08:30 by Snuggles
I found phistomefel useful in this solve
on 6. December 2025, 06:02 by VitP
anyone claiming this is a 5 min puzzle, or level 1, is either trolling, or worse.
there ARE a couple of easy steps that break this puzzle open, but actually FINDING them without extensive testing - not going to happen.
other than that, as long as you use standard gw procedures plus basic sudoku, it's straightforward.
phistomefel gives no advantage.
hint: the 67 pair, and the row 7 4s
on 6. December 2025, 03:20 by QuiltyAsCharged
I had to find some pretty subtle things to break the symmetry of the grid. Nothing overly difficult, but I'm surprised to see people saying it could be 1* difficulty! Very nice puzzle
on 5. December 2025, 21:21 by APigthatflys
Nice set as always, although I didn't fond myself needing to use The Secret at all. Just took a keen eye and lots of colouring
on 5. December 2025, 21:09 by UnknownDjinn
I'm new to variant sudoku. I normally stick to 1 or 2* puzzles. I would say (maybe because I know of the Phistomefel Ring) that this puzzle was on the lower side of 2* maybe even 1*. I had a great bit of fun solving this though. Thank you for the treat!
on 4. December 2025, 18:59 by PinkNickels
Really fun, but it took a bit over 5 minutes. I would say this is a 1*. But still very nice! Maybe a 2* if one isn't familiar with the secret?
on 4. December 2025, 18:46 by Martina
Very nice!
