I am back with another puzzle featuring my bespoke rule variation: Quad Circles that interact with Lines as Cells do. If anyone can think of a better name than "Interactive Quad Circles", I'd love to hear it. As far as I know, I came up with this idea but please do let me know if there is a similar concept that predates mine.
Typically, Line constraints only interact with digits on Sudoku Cells, but in this puzzle they also interact with digits in Quad Circles.
In this example, the Cell highlighted in blue is connected via a Red Parity Line to a Quad Circle containing the digit 1. Because 1 is odd, and Quad Circles would count as values along Parity Lines in this puzzle, the highlighted Cell must contain an even number.
If you enjoy the Interactive Quad Circles concept, please give these other puzzles a try!
Solution code: Column 7 digits, top to bottom
on 31. August 2026, 12:29 by itsid
Lovely break in, and very nice interactions in between.
I think I like the rule set.
thanks for sharing
on 17. August 2026, 22:14 by EYEONYSUS
I would rate this 1* for difficulty, but it was fun and very satisfying!
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