Region Double Sum Lines
(Published on 29. May 2026, 04:06 by Die Hard)
Normal sudoku rules apply. Box borders divide blue lines into regions. The sum of the digits on a region on one side of a box border is double the sum of the digits on a region on the other side.
Please leave a comment if you enjoy this puzzle.
Solution code: All 9 digits in row 1.
Comments
on 8. June 2026, 21:23 by Nemefish
Very lovely smooth puzzle with a nice twist on a common rule set.
on 6. June 2026, 18:33 by TimBoPavey
Thoroughly enjoyable and a rare completion of a 3* for me! Thanks Die Hard!
on 5. June 2026, 04:03 by PancakePie
I felt unsure if I would make it reading the rules, but after the break in I was ecstatic with each new logical step! Beautiful! Fun! Well done! Thank youuuuu! (3* seems right to me)
on 4. June 2026, 09:47 by GandalfLeRouge
Very nice puzzle! Really enjoyed it! I'm rating it 4* though, cause the break in is quite difficult, but so clean though. Loved it!
on 2. June 2026, 23:54 by Laxpanther
No problem solving, but the ruleset is still a bit ambiguous in its wording, as double only works in one direction. Might I suggest using wording with 2:1 ratio as with black dot puzzles?
on 2. June 2026, 18:53 by jez9999
Wow, extremely tough. 5 star for me, I have no idea how this got a 3 star rating! Break in not straightforward, easy to go wrong. Also I think the rules need clarifying. If a line comes into the same box twice, the 2 different line parts in the same box should be considered separately and not summed together.
on 2. June 2026, 15:27 by Kattorzeh
Interesting
on 30. May 2026, 07:14 by econtrout
Really fun rule...well set....
on 30. May 2026, 04:31 by SocratesRanz
Please clarify the blue line rule when the line crosses into the same box twice in box 5. Do (a) r4c5 + r5c6 add together as the sum of that blue line in box 5? Or (b) do those two cells each constitute a separate single-cell sum? Your wording implies (a), but customary RSL rules suggest (b).
Die Hard: b). I clarified the rules above.
on 29. May 2026, 19:39 by Fool on Hill
Excellent puzzle - enjoyed a lot
on 29. May 2026, 18:48 by damo_89
Lovely construction with some great ideas.
on 29. May 2026, 18:17 by BorisTheSnake
Beautiful ruleset and construction. Everything flowed really well, definitely on the harder side for a 3*. Thank you!
