Logic Masters Deutschland e.V.

Eddy (Toroidal masyu)

(Published on 25. January 2026, 15:01 by dumediat)

This puzzle was created based on a comment by isajo4002 in the Sudoku Skunkworks Discord server. I hadn't made a toroidal puzzle before this, so what better time than the present? Shout out to chameleon for developing the Puzzle TV software to allow dynamic visualization of the torus!

Ratings, comments, and feedback are much appreciated! Please feel free to reach out to me on Discord if you have any comments or questions. Please also feel free to try my other puzzles here.

Rules:

  • Masyu: Draw a non-intersecting, non-branching loop through the centers of some orthogonally connected cells. The loop must turn on black circles and travel straight through the cells on either side. The loop must go straight through white circles and turn in at least one of the cells on either side.
  • The grid is a torus (ie, rows 1 and 10 are adjacent, and columns 1 and 10 are adjacent). Therefore, the loop may travel through grid borders (eg, from r1c5 to r10c5) if allowed by other rules.

Penpa (static grid with answer check): https://tinyurl.com/mmkjjh2e

Puzzle TV (dynamic grid without answer check): https://tinyurl.com/mpehzah4

Note: In the Puzzle TV software, the button on the bottom-right allows one to move the grid, and the button above it returns to loop drawing. There is a conflict checker that will turn a loop segment red if it violates any masyu rules.

Solution code: For each row of the pictured grid (top-to-bottom), the number of turns the loop makes (10 characters)

Last changed on on 27. January 2026, 22:12

Solved by Myxo, Mr_tn, dogfarts, KNT, Bellsita, Leaving Leaves, Calesch, Dragonslayer, Piatato, Christounet, Jesper, Playmaker6174, CHalb, itweb, LeiZ123321, JustinTucker, zzw, Statistica, The Book Wyrm, CJK, webato, puzzler05, MaizeGator, sehringdipity, misko, ns08, ManuH
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Comments

on 27. January 2026, 23:23 by zzw
Very nice! Simple idea executed cleanly with just enough toroidal madness and a smooth interesting path.

on 27. January 2026, 22:12 by dumediat
Fixed Puzzle TV link

on 27. January 2026, 00:32 by Playmaker6174
Oof, quite trippy scanning throughout but the flow was pleasant enough to follow. I liked how connectivity was determined at certain spots x)

on 26. January 2026, 09:04 by Christounet
Cool puzzle. Not easy to visualize connectivity towards the end.

on 26. January 2026, 08:25 by Piatato
Lovely!

on 26. January 2026, 03:16 by dumediat
Updated Puzzle TV link with version that includes conflict checker.

on 25. January 2026, 15:10 by Myxo
Awesome puzzle!

Difficulty:3
Rating:91 %
Solved:27 times
Observed:0 times
ID:000R5X

Puzzle variant Online solving tool Wraparound Path puzzle

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