Extension Cord 103: Parity Sums
(Published on 28. January 2026, 08:30 by FireTruckFuel)
Normal 6x6 Sudoku rules apply.
Box borders divide the blue Region Sum line into sections, each with the same sum.
Adjacent digits along the red Parity line alternate between odd and even.
The black Extension Cord line connects all other lines it touches so that segments of the same type are joined together by adjacent ends along its stretch. (r2c6 "touches" both r1c4 and r4c4) The length and path of an Extension Cord does not need to be assumed. It continues underneath other lines and does not branch unless specified. It may begin and end outside the grid to clarify its path or length.
Ready for the next puzzle? Extension Cord 104: Whispering Arrows
Solution code: Row 3
Comments
on 29. January 2026, 11:06 by wuc
Still a bit of thinking how the rules fit on new concepts. But I really liked this one as well. Great idea. Keep going.
on 29. January 2026, 00:53 by dzamie
This is my favorite of the series so far. It's the easiest to read, and the connections play very well together. Honestly, I think this might make a better introduction to the extension cord rule than either of the earlier ones.
The "touches" example might be better if you mentioned how it affects the rules - rather than r2c6 being connected to both r1c4 and r4c4, it might be clearer to say that the RSL on r2c6 directly touches the RSL on r1c4, and the parity line on r2c6 directly touches the parity line on r4c4.
on 28. January 2026, 10:37 by SennyK
Are you sure your example is correct? I would assume R2C6 "touches" R1C4 and R3C5, but does not "touch" R4C4
edit: I was thinking of RSL, but I can see that you meant different cells for different lines
on 28. January 2026, 10:05 by superkinkel
One star difficulty in my book. While I now understand why you had the unnecessary breaks in the lines on 101 and 102, I don’t think it really is a tutorial for this one. “Continues under other lines” is all that has to be remembered …
But the concept is certainly growing on me, curious for the next installment and to see what it can do in full Sudoku …
