Puzzles #665, #666 & #667 - 24HPC Zodiac (NIKOJI, Nurimisaki, Balance Loop)

I also contributed several puzzles to the Puzzlers Club rounds at the 2024 24 Hour Puzzle Championship this year. We authored two rounds, each with 24 puzzles. The first round had one puzzle themed on each Greek letter, while the second round was a double zodiac (signs and animals).

Even though I've already done a Puzzle Zodiac before and wasn't too enthused by this theme, I still made 3 puzzles for the zodiac signs side of things. NIKOJI is otherwise known as Gemini Block, which was a type I was unaware of at the time of my original Puzzle Zodiac. The bottom row not being a word was kind of annoying, but I tried using Qat to find any words that could work and none existed. This was worth 30 points in the round.

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Cats like to curl up in corners. Nurimisaki is a type all about corners. It's a bit of a stretch but I like the genre and had originally thought of the type for PZ, even though I went with Akari at the time. I checked with some solver assistance to see if there was any way of avoiding the extra circle in the top left corner and unfortunately found that it was impossible to specify that corner without another clue. Puzzle is worth 25 points.

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To round out the comparison, I grabbed Libra to make a Balance Loop worth 50 points. This was one of the biggest missed opportunities of the original PZ in the name of genre balance, and while I don't regret my old choice of Minarism... this Balance Loop is way, way better. I did have a working version without that center clue at one point, but this required neutering a lot of the logic in the second half of the solve, so I sacrificed the purity of the theming for the sake of a much better puzzle. In general I skewed a bit larger on grid size this 24HPC to try to prevent undershooting round length again, and as a whole we succeeded -  the rounds were maybe a bit oversized, but well within acceptable ranges for the 24HPC as a whole.

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Puzzle #646 - Numbers are Overrated (Nurimisaki)

Someone in Puzzlers Club mentioned a Nurimisaki pattern that would force a deduction, which put me in the mood to make one. So I did, finding my own neat pattern that somehow managed to finish without needing any clue numbers. This is such a fun genre.

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Puzzles #477 & #478 - More Nurimisaki

I ended up making a couple more Nurimisaki puzzles after Nurimisaki Nomad. The type is just fun to play around with even if making aesthetic puzzles with it is extremely hard - the type often just keeps going, and also can have unresolvable ambiguities crop up late in a puzzle.

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I was really surprised to find that an empty space that large would resolve by itself from just border 6s. A pretty neat easy puzzle.

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This one has a bit more bite to it and some fun connectivity arguments. The bottom right working was also a bit surprising, but I find that there's something surprising in most Nurimisaki puzzles, when looking for areas that don't look like they should work!

Puzzle #413 - Celebratory Trophy (Nurimisaki)

Nurimisaki Nomad, the latest daily contest series on LMI just concluded. After a hard-fought battle with a couple stumbles on my part (but 7 first places!) I managed to scrape a 4 point win over Walker Anderson in what I believe is the closest final score for one of these to date. The puzzles are all excellent and I highly recommend checking them out if you haven't already! This is my 2nd win, and to celebrate, I made a Nurimisaki in the shape of a trophy.

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I know I've been promising more posts for a while and I have a hefty backlog to post so hopefully I find the time to actually put together the posts soon.

Puzzles #391 - 400 - MadMahogany's Christmas Tree Conundrum (Shading and Sudoku Medley)

Like the last two years, I took part in the Secret Solver event on Puzzlers Club. This time around, I got MadMahogany, someone I mostly know is semi-active (I think?) on the CTC Discord, and some of their most memorable puzzles they've posted to their blog have been shading or sudoku puzzles. Sudoku is obviously outside my general comfort zone, but whatever, this was the perfect opportunity to go big and make something incredible. So I made a Samurai Sudoku shaped like a Christmas tree with different variants in each subgrid. Rules after the puzzle images.

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Nurikabe | Tasquare | Canal View | Nuribou | Nurimisaki | Kurotto | Mochikoro | Cave | Kurodoko

I also decided to make a collection of 5x5 shading puzzles themed on 12/25 (as close as I could get it) for each shading puzzle variant in the big puzzle. Rules for Nurikabe, Tasquare, Canal View, Nuribou, Kurotto, Kurodoko, Nurimisaki, Mochikoro and Cave can be found linked here, as well as Sudoku. These 9 puzzles were a last minute addition when I finished with time to spare, and I thought it would be nice to have a brief reminder / demonstration of the shading rules before having to dig into the tree itself.

"penpa" link (the URL is too long for some browsers, so go to Penpa, select "Load" from the top bar, and paste the URL from the pastebin into that box to load the puzzle)

So, here's the tree. Standard rules apply for each puzzle type within each labelled subgrid. Some grids overlap: the contents must satisfy all rules from both grids when taken only for that grid. As an example, Kurodoko requires shaded cells to not be adjacent to other shaded cells. This rule only applies within the Kurodoko grid, and so a shaded cell on the edge could be adjacent to a shaded cell in another grid. Any cell with an outlined gray circle will have its value act as a clue for the shading puzzle in that grid. Note that most thermos and arrows have the circles coincide with shading clues, but not all. A rundown of each variant rule follows. Star Battle - 1s and 2s may not share an edge or corner with each other. Thermo - numbers must strictly increase from the circle to the end. Arrow - the sum of all numbers on the arrow must equal the number in the circle. Classic - no additional restrictions apply. XV - Cells separated by a V must sum to 5. Cells separated by an X must sum to 10. Cells separated by an XV must sum to 15. Not all Xs or Vs are given. Kropki - Cells separated by a white dot must differ by exactly 1. Cells separated by a black dot must have one number be exactly double the other number. Not all dots are given. Difference - Cells separated by a red dot must have a difference of the number inside the dot. Killer - Cells inside a cage must sum to the value in the cage, and must not repeat within a cage. Product - Cells separated by a pentagon must have a product of the number inside the pentagon.

This puzzle took me probably 30 hours across several weeks to construct, and I got to work with a couple rulesets I'd never worked with before. Like overlapping grids (somehow this was new to me- many headaches from contradictions across grids though...), most of these number placement variants (Arrows are a huge pain, and Killer is way harder than I thought it would be), and Mochikoro and Canal View (fun and easy, painful and difficult. Though some of the Canal View pain was from the other restrictions, it's hard to make unique!). Special mention goes to the Nurikabe for being an absolutely massive gigantic pain to make unique, and the Cave, and the Kurotto section, and generally huge parts of this puzzle barely work. But it all comes together beautifully and I'm very proud of what I came up with here. And my solver liked it, too. :)

I'd also like to take this space to thank Rever for testsolving most of this puzzle before I sent it out, Swaroop for updating Penpa to even support grids this big, and djmathman for making the gift I received, which is really quite excellent.

That's all for now, sorry about the inactivity here, more puzzles soon once I write up the posts for them because I have another 8 waiting already. Errata: added a white kropki dot I thought was unnecessary, but was made necessary due to a bad deduction in completely different section.

Puzzle #193 - Fourced Triangle (Nurimisaki)

Nurimisaki seems to have no end to interesting clue combinations, as the ruleset can force quite a bit from a few seeds. Guiding that process is still fascinating to me, and I feel like I've barely scratched the surface of what the type can do.

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Puzzle #187 - Good Knight (Nurimisaki)

Symmetry as a visual theme is fairly standard in my puzzles, as it guides the construction process and results in some striking designs sometimes. Nurimisaki has proven very difficult to apply symmetry to, as the rules of the puzzle can often result in a cascade of deductions into a contradiction. I managed to succeed here, though, and with an extra restriction!

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Puzzle #186 - Clueless? (Nurimisaki)

A somewhat common theme for Nurimisaki puzzles is to only use numberless circles. I wanted to go one step farther in this puzzle and not have any adjacent circles, which proved very difficult to force a unique solution with. I made this after noting that an arrangement of circles I placed in tomorrow's puzzle gave a ton of information on its own, and thought it was worth building a puzzle around.

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Puzzle #179 - Hidey Holes (Liar Nurimisaki)

 You guys know the drill by now. Solve as a regular Nurimisaki puzzle, except all numbers in the grid are lying and should actually be another number. So a 3 can see 2, 4, 5, 6 or more cells, but never 3.

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Puzzle #152 - Three Ways (Nurimisaki)

Well. I finally got around to making a Nurimisaki puzzle. Hopefully this is somewhat tricky. There's a very clean path through this puzzle, but I wonder how many will actually find it?

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