Black Dot Fortress
(Published on 23. May 2026, 01:00 by yttrio)
Rules:
Normal Sudoku rules apply.
Digits separated by a black dot have a ratio of 2:1. Not all possible dots are necessarily given.
All cells with a black dot on at least one edge act as fortress (maximum) cells: Cells with a black dot on an edge must be larger than all orthogonal neighbors of the cell that do not have a black dot on at least one edge.
Solution code: Row 8
Comments
on 25. May 2026, 05:51 by alarac
using color helped with solving but overall would put it at 2*
on 24. May 2026, 03:15 by CarnacTheMagnificent
Great puzzle. First time solving a puzzle with the Fortress rule. I was amazed how the given information was enough to solve this. Thank you very much for this puzzle. I'm adding this to my favorite puzzle section.
on 23. May 2026, 23:00 by henryng
Neat puzzle! A bit tricky remembering that the fortress rule doesn't apply to other fortresses, though obviously it would be impossible
on 23. May 2026, 21:36 by Pairot
I also think it's a 2*
Very fun, but challenging.
on 23. May 2026, 17:24 by superkinkel
Very nice and very easy after figuring out the break-in. That however is not that easy, so I think it rather borders on two stars.
on 23. May 2026, 15:07 by Franjo
Thank you very much for creating and sharing another unusual (and quite easy) puzzle.
on 23. May 2026, 14:12 by Plok
Great rule set. Once I understood the dynamics of the rule it is fairly easy.
on 23. May 2026, 13:01 by Martina
I really love that rule. Simple and powerful.
on 23. May 2026, 10:49 by Wuschel
Really great puzzle, but I disagree with the very easy rating.
Thank you yttrio!
