Quattuor (Quadruples, Quad Sums)
(Published on 24. February 2026, 15:30 by Crusader175)
Normal sudoku rules apply.
Quadruples: A digit shown in a circle must appear at least once in the four surrounding cells.
Quad Sums: Four digits around a circle may repeat, and one digit must equal the sum of the other three digits.
Puzzle Link: SudokuPad
My youtube channel on solving sudoku: Crusader Puzzle
Solution code: Row 9
Comments
on 25. February 2026, 05:13 by ketchup_monster
beautifully smooth
on 24. February 2026, 22:02 by Tobias
Nice puzzle. Updated rule set is clear to me. Rating should be 1* imo
on 24. February 2026, 20:36 by Crusader175
Update the rules. Hopefully it's clear now?
on 24. February 2026, 20:26 by Franjo
Thank you very much for creating and sharing this beautiful puzzle.
on 24. February 2026, 20:07 by VitP
solves very easily.
level 1 ?, maybe level 2.
IMPORTANT:
the second rule definitely needs to be rewritten as "the 4 cells surrounding each circle contain a set of digits (which may include repeats), with 3 of the digits adding to the fourth" or something like that
on 24. February 2026, 19:52 by jhow25
the quad sum rules are very unclear. "At a corner," there are no circles at any corners. Are you saying every circle is also a quad sum?
on 24. February 2026, 17:04 by Mad-Tyas
Very nice and smooth!
on 24. February 2026, 15:39 by wisty
Amazing!!! Such an elegant solve from such an elegant looking grid. Thank you so much for sharing!
