Logic Masters Deutschland e.V.

Zodiac Project: the year of the dög

(Eingestellt am 20. November 2025, 00:55 Uhr von aqjhs)

So Sotehr nominated me to continue the sudoku chain of The Zodiac Project as started by ViKingPrime. It consists on setting a sudoku puzzle using a constellation (extra region) chosen by the previous setter.

I knew I had to make a Doppel-Dög puzzle but the extra region I was given proved to be a challenge for it... so it got a few upgrades to a toroidal Doppelgänger setting. Hope you like it!

TL;DR Rules: Doppelgänger sudoku with the usual min.diff.5 Doppel-Dög (with its circle sweepers and same-value balls) on a toroidal grid. Dög loop must pass through every tree, and trees are a full set 1-9. Cages have the same value sum.

  • Doppelgänger Sudoku:
    • Fill each cell of the main 9x9 grid such that every row, column and 3x3 box contains a 0 and eight different digits from 1-9.
    • No two rows, no two columns, and no two boxes may be missing the same digit.
    • For each 0 in the grid, the digits missing in its row, column and region must be three different digits.
  • Extra region: The cells marked with trees 🌳 🌲 contain different digits from 1 to 9. Differences in trees are merely cosmetic.
  • The grid is toroidal:
    • Each edge of the grid is considered to be adjacent/orthogonal to its opposite edge. (For example, r1c2 is considered to be orthogonally adjacent to r9c2.)
    • Lines wrap around opposite sides of the grid.
    • Clues outside the grid are for visual aid.
  • Doppel-Dög loop:
    • Draw an orthogonal non-branching closed loop that doesn't cross or touch itself, not even diagonally.
    • The loop must pass through every cell marked with a tree, regardless of its shape. 🌳 🌲
    • The loop "starts" at the cell marked with the dog and is considered to be oriented in the direction indicated by the arrow (i.e. r4c7 and r4c6 are on the loop).
    • A cell on the loop with a digit D will have a value equal to the digit D steps away along the loop in the orientation given by the arrow.
    • Cells not on the loop will have a value equal to the digit in them.
  • Adjacent digits (not values) along the loop must have a difference of at least 5.
  • Cells marked with a circle are not part of the loop, and have a digit that equal to the count of the, up to 8, neighboring loop cells.
  • Cells joined by a ball have the same value.
  • All parks (cages) have the same value sum. Digits do not repeat in parks but values may repeat.

Online in Sudokupad (and with extra note space).

The Zodiac Project:

Thanks to Sotehr, ThePedallingPianist and ChinStrap for testing the multiple iterations of this puzzle.

For the next installment of this series I nominate Nell Gwyn and this is the constellation I'm giving to her.

R1C5 R4C3 R7C1
R6C3 R6C5 R6C8
R7C7 R7C9 R8C8

Lösungscode: Values on the column missing the digit 5, top to bottom.

Zuletzt geändert am 20. November 2025, 21:43 Uhr

Gelöst von ViKingPrime, zeniko, ThePedallingPianist, Sotehr, Fusce, lmdemasi, han233ing, ChinStrap, Isael, Lyouke, kodra22, War, tuturitu
Komplette Liste

Kommentare

am 25. November 2025, 17:22 Uhr von War
Excellent. The solve path was beautiful. Once the 0s started dropping in the whole puzzle fell into place. Other than the 0s interacting with other rules, the doppelganger felt like it was sidelined until the end, but the whole puzzle logic was captivating.

am 22. November 2025, 12:28 Uhr von Isael
Wow! It feels like several puzzles in a row

am 20. November 2025, 13:49 Uhr von Sotehr
Perhaps slightly more difficult than a walk in the park, but arguably more enjoyable!

am 20. November 2025, 11:37 Uhr von ThePedallingPianist
Another mind-bendingly awesome construction from aqjhs! The steps are not actually brutally difficult, but the logic is so creative and the solution path so beautifully narrow that it's definitely worth setting aside some time and mental energy for this one, as, unlike our protagonist, you may easily find yourself barking up the wrong tree.

am 20. November 2025, 11:22 Uhr von zeniko
As tricky as this puzzle looked initially, it did flow slowly but steadily, always giving just the right amount of resistance. Just don‘t let this be your first Doppel-Dög… Thanks for sharing these marvels.

Zuletzt geändert am 20. November 2025, 01:32 Uhr

am 20. November 2025, 01:30 Uhr von ViKingPrime
Be careful of gazing too long at this puzzle, lest it gaze back into you...
To solve an aqjhs puzzle is to risk madness in the Lovecraftian sense, intellectual curiousity leading inevitably to uncovering the terrifying indifference of a vast and uncaring universe (but, like, in a good way).

Schwierigkeit:5
Bewertung:100 %
Gelöst:13 mal
Beobachtet:0 mal
ID:000PZD

Variantenkombination Neu Kantenverklebung

Lösung abgeben

Lösungscode:

Anmelden