(4.) Unique Sets

I noticed I forgot to specify a rule yesterday: the rule that numbers may not repeat within a region. I did correct it soon enough after posting the puzzle, though.

A version without a no-repeats rule could well be interesting as well: then, there’s a choice on how to interpret regions with repeated numbers.

  • The choice faithful to the name would be to ignore repeated numbers: for example. a region with {1, 1, blank} would have the same set as a region with just {1}.The example puzzle on the rules page actually solves under these rules as well (as does yesterday’s puzzle, unsurprisingly).
  • The other choice would be to consider them distinct: that is, the regions would be multisets. This would probably be the less interesting variant, but it could work well in sparser puzzles.

Anyways, today’s puzzle operates under the no-repeats rule.

004 Unique Sets 2

Standard Unique Sets rules.

Perplexible picks: Masyu variants

Neither one has a fully symmetric clue layout, but I’m happy with them as they are.

Regular Masyu rules.


Alternating Liars Masyu 2The full title of this one is Alternating Liars Masyu. In addition to regular Masyu rules, half the clues are liars: that is, a liar white pearl acts like a black pearl, and vice versa. The loop must alternate between truthful and liar pearls: going around the loop, every other pearl must be a liar.


Alternating Masyu 1This one is an Alternating Masyu. In addition to regular Masyu rules, the loop must alternate between white and black pearls: going around the loop, every other pearl must be black.

While using guesswork might be tempting, there is a particular insight this puzzle was built around.