DDDDoppelgänger
(Published on 12. December 2025, 19:19 by mellowrobinson)
Inspired by puzzles from Fenners and Oskode, I've put a Chaos Construction inside a Doppelgänger, so that each 0 is missing four different digits from its row, column, box, and Chaos region. Big thanks to LMDemasi, Oskode, and laquartetfan for testing.
- 4D Chaos:
- Divide the 9x9 grid into nine orthogonally connected '4D' regions.
- The digit in a circle indicates how many cells of its 4D region are in the same 3x3 box as the circle.
- All circles are given.
- Doppelgänger:
- Fill each cell of the main 9x9 grid such that every row, column, 3x3 box, and 4D region contains a 0 and eight different digits from 1-9.
- No two rows, no two columns, no two 3x3 boxes and no two 4D regions may be missing the same digit.
- For each 0 in the grid, the digits missing in its row, column, 3x3 box and 4D region must be four different digits.
- Space outside the grid can be used to track missing digits, but is not required for completion.
- Arrows:
- A digit N in a cell with an arrow points to a cell N steps away within the 9x9 grid that contains the digit missing from the 4D region that the arrow is in. Not all arrows are given.
Solution code: Column 8 of the main grid, with a dash (-) for 4D region borders.
Comments
on 4. January 2026, 16:57 by wullemuus
What a pleasure to see that so many new creative puzzles with the Doppelgänger logic are set in these days! Congrats to this extraordinary and intricate, but always balanced version!
on 24. December 2025, 06:55 by h5663454
Cool!੭ ᐕ)੭*⁾⁾
on 14. December 2025, 22:24 by marcmees
very hard but rewarding CC solve. Thanks
on 13. December 2025, 20:04 by Snookerfan
Absolutely brilliant and bonkers! One of the hardest puzzles I have ever managed to solve. Such a satisfying process. Thanks for this gem!
on 13. December 2025, 10:02 by oskode
Most fun I've had with a puzzle all year. Fantastic work!
on 13. December 2025, 04:23 by War
Amazing combination of all my favorite variants!
on 13. December 2025, 03:58 by mellowrobinson
formatting
