The 15-Box Odyssey
(Published on 11. October 2025, 10:00 by Duarte-Carvalho)
Rules:
Draw fifteen 3×3 boxes within the grid and place the digits 1–9 once in each box.
Digits within boxes must not repeat in any row or column on the grid.
All the given clues on the grid are each one entirely inside of one unique 3X3 box.
All the cells outside of the 15 3X3 boxes must be filled with 0's.
The grid is mostly covered by fog; entering a correct digit may clear some fog anywhere on the grid.
Arrows: the digits along the arrow must sum to the number in the circled cells.
Kropki: digits separated by a white dot are consecutive; digits separated by a black dot are in an 1:2 ratio (i.e. one digit is double the other).
Renban: purple lines must contain a set of consecutive digits in any order.
Quadruplets: every digit in a circle must be assigned to one of the four surrounding cells.
Killer cages: digits in a killer cage must sum to the number in the top left corner and cannot repeat.
German whispers: adjacent digits on a green line must differ by at least 5.
Thermometer: digits on a thermometer must strictly increase from the bulb to the tip.
XV: digits separated by an X must sum to 10; digits separated by a V must sum to 5.
Skyscrapers: Clues outside of the grid give the number of skyscrapers visible from that point in that row or column. Digits in the grid represent the heights of the skyscrapers. Taller skyscrapers block the view of any smaller skyscrapers behind them. (the 0's do not influence the skyscrapers view).
Solve online here: SudokuPad Puzzle
If you like this puzzle you may enjoy some of my other puzzles too, click HERE to see the other puzzles I have made.
Solution code: All the digits on german whispers lines (smallest to biggest)
Comments
today, 08:11 by etoler
Just incredible. A very long solve for me, but worth every second. Thank you for sharing this masterpiece!
yesterday, 23:53 by War
Approachable and fun, thanks!
yesterday, 13:27 by Snookerfan
Great puzzle! Very long and enjoyable solve with some, at least for me, very hard steps. Thank you
yesterday, 01:15 by Starlight
Really enjoyed this. I needed some breaks due to the sheer size and time it took me but I loved it. Awesome work
on 11. October 2025, 17:42 by Zibl
One of the longest sudoku journeys I've ever undertaken. Well worth the trip, fantastic puzzle! :)
on 11. October 2025, 17:03 by dickey
Nice one
on 11. October 2025, 15:51 by Duarte-Carvalho
clarifying the rules.
on 11. October 2025, 15:39 by jinkela114514
Does a skysraper blocks any skyscrapers behind it with the same height? For example, if the non zero digits in a row from left to right are 1, 2, 3, 3, 4, 5, should the clue be a 5 or a 6?
The non 0 digits can not repeat in any row or column.
