Sub-Zero
(Published on 12. March 2026, 15:25 by M.K.)
Rules:
- Normal sudoku rules apply, with one exception: Place the digits 0-8 instead of 1-9.
- Digits in a cage cannot repeat and sum to the small number in its corner.
- The 3x3 box borders divide blue lines into segments – each segment on an individual line has the same sum.
- Every digit that stands below a 0 counts as negative regarding summation.
- There are 8 different sub-zero digits in the grid – no row, column, or 3x3 box can have more than one sub-zero digit.
Link: SudokuPad
Solution code: Row 5 + Column 1
Comments
on 13. May 2026, 11:08 by M.K.
@Frank Puzzles: I don't see the difference between the words "different" and "unique" in the given context. I'm curious: What multiple interpretations do you see?
on 9. May 2026, 21:55 by Frank Puzzles
Nice rule set and setting. A friendly suggestion. I would choose the word "Unique" instead of different for the 8 sub-zero digits, as different could have multiple interpretations.
on 26. March 2026, 13:20 by M.K.
Watch Mark solve this puzzle on CTC:
https://www.youtube.com/watch?v=jtQcQ-Y8Ur0
on 25. March 2026, 12:18 by QuiltyAsCharged
Fun and creative puzzle!
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Thanks! (M.K.)
on 25. March 2026, 11:49 by bhambells
Nice puzzle, but no need for such a long solution code..
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I contemplate putting a shorter solution code into the embedded solution. (M.K.)
on 19. March 2026, 18:38 by bleppie
Nice concept, a few tricky bits, smooth solve, thanks!
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The concept was born when I tried to fit the zero into a 9x9 grid. And I always wanted to use that title. Thanks for solving! (M.K.)
on 13. March 2026, 21:43 by dzamie
That was really interesting! Easier than I had anticipated, but certainly quite challenging. There are a lot of interesting and unique deductions that get made.
(plus, I had fun pretending to levitate shapes above themselves to look for negatives)
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Glad you liked it. Thanks for solving! (M.K.)
