Puzzle 381 (Nurikabe/Tapa) [Mastermind]

This is a Nurikabe / Tapa Mastermind puzzle. Solve the left grid as a Nurikabe and the right grid as a Tapa. The gray numbers between corresponding rows represent Mastermind clues. If one were to superimpose the two solutions (without rotation or reflection), the gray number in a row tells exactly how many squares are shaded in both grids.

Puzzle 381

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Puzzle 377 (Numberlink)

This is a Numberlink puzzle.

Puzzle 377

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The symmetry and lack of edge clues was as hard to pull off as it looks like, both in constructing and proving uniqueness. I don’t think the puzzle itself is that difficult though.

Puzzle 373 (Masyu) [Optional Blacks]

This is a Masyu puzzle, with a twist. The loop is not required to pass through black circles. But if a black circle is passed through, it still functions like it would in ordinary Masyu.

Puzzle 373

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The gimmick in this puzzle means that trial and error strategies are likely to get you the solution in short order. So I did my best to make the logical path as clean as possible, and I mostly succeeded. For maximum enjoyment and challenge, avoid any if-then sequences of significant depth.

Puzzle 369 (Nurikabe)

This is a Nurikabe puzzle.

Puzzle 369

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Puzzle 365 (Castle Wall) [Anti-symmetric]

This is a Castle Wall puzzle, with a twist. None of the clue colors are given initially. For each symmetric pair of clues, exactly one is inside the loop (white) and exactly one is outside the loop (black).

Puzzle 365

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Unrelated to this puzzle: if you’re a Fillomino fan, you will enjoy this puzzle from Anderson Wang, a regular USPC/LMI competitor and someone I’ve met in real life through math contests. His other content is worth doing too, but that one stands out.

Puzzle 250 (Nurikabe) [Marathon]

This is a Sunday Nurikabe marathon. That is, it is a very large and very difficult Nurikabe puzzle.

Puzzle 250

I have some unfortunate news. With the exception of a total eight days of break, this blog has had one puzzle go up every day for over 200 days now. Tomorrow that will end. There will likely still be updates to this blog, but they will be much more sparse, perhaps around once per week. (and obviously puzzle difficulties will no longer be aligned with the days of the week)

The primary reason is that there are a number of puzzle-related projects I have been wanting to do for months. None of them were things I could find the time to do concurrently with keeping up the schedule on this blog. In addition, although my idea well is not dry, for logic puzzles like these it is not at the depth it used to be, and there are several that I’m putting in reserve for the aforementioned projects.

It doesn’t help that with every post here my publishing standards increase. A lot of time recently has been spent starting or making puzzles that I threw into the reject pile, ones I may have been happy to use in the past. Added with the time spent on puzzles that do go up, that’s an enormous investment.

I should also note that I may begin to put up some additional posts without puzzles. This will be exclusively a puzzle blog, but I may share many of the things I’ve learned about puzzle solving and construction, and some of my philosophies regarding them.

Thanks a lot to everyone who read, solved, or commented here. We’ll still be going, just not as strong as before.

Puzzle 249 (Akari)

This is a Sunday Akari puzzle.

Puzzle 249

What kind of Sunday puzzle is this?

Puzzle 242 (Castle Wall)

This is a Sunday Castle Wall puzzle.

Puzzle 242

Puzzle 235 (Country Road)

This is a Sunday Country Road puzzle.

Puzzle 235

Puzzle 228 (In-Out Slitherlink)

This is a Sunday In-Out Slitherlink puzzle.

Puzzle 228

This puzzle was made shortly after I did the one posted here by a Japanese author, whom I do not know although he apparently has seen this site. In my attempt to give feedback (albeit in English) on his post I was thwarted by a Japanese CAPTCHA, so apparently on Japanese sites I am indistinguishable from a spam bot. Darn.

To compensate, here is my shout-out and tribute to that construction. The main ideas employed aren’t that similar; I was mainly trying to put to thorough use a number of deductions that I learned while doing that puzzle.