Erica 39 (Modular Edition)
(Published on 13. March 2026, 13:45 by SennyK)
Today Erica is exploring the interactions between German whisper lines and modular lines :-)
I hope you will enjoy and I would be really grateful for all the comments and ratings.
Normal sudoku rules apply.
German whisper: Adjacent digits along a green line have a difference of at least 5.
Modular: Any sequence of 3 adjacent digits along a teal line must contain a complete set of residuals modulo 3, i.e: one from (1,4,7), one from (2,5,8) and one from (3,6,9).
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 necessarily given.
Modular Line Explanation:
Basically, if one digit on the line is from one of the groups of residuals modulo 3, then every third digit will also be from the same group; same applies for the remaining groups.
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, 31, 32
★★☆☆☆: 3, 7, 8, 10, 11, 13, 14, 16, 18, 20, 24, 25, 29, 30, 34, 35, 38
★★★☆☆: 9, 19, 21, 22, 28, 33, 37, 38
★★★★☆: 36 Shading/Ying-Yang:
★★☆☆☆: Pretty Odd Shaded Area
★★★☆☆: (+5)-Yang, Negative 8 YY
★★★★☆: Aim High! (YY)
★★★★★: Why-Why? Modifiers:
★★★☆☆: Modified Flat Mates, Neighbourhood Watch 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, Erica 29
★★★☆☆: Broken Flashlight in the Dark Pencil Puzzle/Sudoku Hybrid:
★★☆☆☆: Masyu (Short) Sudoku, Heyawake Sudoku (Given Regions)
★★★☆☆: Tetromino Sudoku
★★★★★: Heyawake Sudoku
Pairometers:
★★☆☆☆: Pairometers (6x6 Pack 1), Pairometers
★★★☆☆: Pairometers (6x6 Pack 2), Pairometers (6x6 Pack 3) Various Puzzles:
★☆☆☆☆: Blown Fuses in Electrical Installation, Let Me Introduce Myself, French Wrench, GAS Regional Constraints, Quadsumes, Snack Latin Arrows
★★☆☆☆: Symmetrical Fan, Night Club, Important Hour on the Clock, What Was the Sum Again?, Disgroup Joints, 10-Arrows, Antiking Dutch Skyscrapers, (Not so) Little Killers, Indexing Sword, Larna's HoneyMoon
★★★☆☆: Cops & Robbers, Positive Symmetry, Doppelgänger Killer 1-25, Region Whisper Line, Christmas Chaos
★★★★☆: Liars. Liars Everywhere., Sandwiched XV Squishmates, Fireworks 2025, (Yin)German Pairrows
★★★★★: Any NEWS?, Potentially Pointer, Possibly Parity Party
Solution code: Ninth (9th) row of the grid from left to right.
Comments
on 16. March 2026, 15:21 by blackjackfitz
Huzzah!
on 15. March 2026, 16:01 by hundertzwoelf
Absolutely brutal! Took me many hours...
on 14. March 2026, 17:58 by Snookerfan
Very nice and tough puzzle! Thanks
on 13. March 2026, 21:04 by Exigus
Very nice build up with a flurry at the end. Thanks!
on 13. March 2026, 18:06 by sfield
Excellent puzzle. Only attempted a 4 star because this is a really good puzzle series. After playing around for a while, I figured out that you could make some assumptions without loss of generality as long as you were prepared to swap around some answers later. Tried doing that first with letters, but I messed up some of the deductions. So I redid it based on what I had learned using numbers, but I messed up the process of swapping them. So I did it one last time, now knowing which assumption was correct in advance so I wouldn't have to swap later and that went very quick after I already spent so much time learning the puzzle.
