Puzzle #290 - Christmasyu Part 2 (Masyu Medley)

This is the second part of my Christmas gift for my mom- a Masyu variation mashup. I'll copy the rules I gave in the pdf I printed after the puzzle.

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Each 8x8 subsection of the puzzle obeys the rules of one of the Masyu variants [in the previous post]. Standard Masyu rules apply in all subsections, and a summary of all rules follows below.
Alternating: For the circles within this subsection, the loop must alternate touching black and white circles. This restriction does not apply outside the subsection. As an example, the loop may touch a black circle in the subsection, a black circle outside it, and then a white circle inside. However, black in, white out, black in is invalid.
Standard: No additional rules.
Deformable: White circles in this subsection may be filled in and act like black circles instead.
All Cells: All cells in this subsection must be used.
Tetromino: Cells not used by the loop in this subsection should form tetrominos. Each of the 5 shapes (I, L, O, S and T) must appear exactly once. Unused cells across subregion boundaries do not count for this restriction.
Dynasty: Cells not used by the loop in this subsection may not be orthogonally adjacent. Unused cells across subregion boundaries do not count for this restriction.

Enjoy the puzzle! I really enjoyed putting this together and was extremely surprised that the lower left would work like that! The difficulty is mostly fairly low here, but since this was for my mom... that just makes it more accessible to everyone else, doesn't it? 😁

Puzzles #284 - #289 - Christmasyu Part 1 (Masyu Sampler)

For Christmas, I made some puzzles for my family! My mom enjoyed Masyu from Logic Puzzles 101, so I made her a set of relatively easy Masyu and variations. And a large puzzle using all of the variants in one, which you'll see tomorrow.

Standard Masyu

Standard Masyu rules apply, with no additional rules. I wanted to ease my mom back into the type with a very easy example, though it still turned out a bit easier than I wanted from uniquely specifying the outside. It served its purpose well.

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Alternating Masyu

The loop must alternate touching black circles and white circles. Antisymmetry alllllllmost worked here with a fun and fair solve- the corners break it. That said, the corners still made for a nice resolution and I like this puzzle.

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Deformable Masyu

White circles may be "deformed" by filling them in to create a black circle. This one is my favorite of the set purely due to the theme. My mom thought this variant was very mean but ended up solving it without too much trouble, as intended.

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All Cells Masyu

The loop must travel through every cell in the grid. Can you tell that I was more focused on aesthetic themes for these puzzles than intricate logic? I love how the top right corner ends up working out and flows here.

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Dynasty Masyu

Cells unused by the loop may not be adjacent. This variant proved much tougher to grasp than I anticipated, even if I thought most of the deductions were straightforward. The top left in particular was something that my mom struggled with seeing how it could even work, even though it largely doesn't use the variant.

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Tetromino Masyu

The cells left unused by the loop must form the indicated set of tetrominos. In this puzzle, the set is O, I, L, S. This puzzle gave me so much trouble to construct as placing circles would often render the puzzle unresolvable from that point, and even placing all the shapes wouldn't give a place where a circle could go. Eventually I found an extra black circle I could place that made the puzzle much nicer, thankfully.

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Puzzle #283 - Invisible Barrier (Barns)

This Barns puzzle is a bit unconventional, and I made it to highlight a specific kind of deduction. Should be pretty easy with the right idea and nearly impossible without it.

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Puzzles #278 - #282 - Pie in the Sky (Spiral Galaxies)

In a reversal of how I usually handle these posts, comments for these Spiral Galaxies puzzles will be after the puzzles themselves.

Themeless

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Barrier

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Gravity

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Cornered

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Opposition

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Alright, have you solved them all yet?

You have? Good- spoilers ahead.

These were all failed attempts at a Tatami Tentaisho- the "no +" constraint just wasn't strong enough to drive a solve while also resulting in a puzzle that needed the constraint. I tested all of these in the excellent myamya solver to see if the variant rule was necessary, and every time it came up unique without it. Though the second one broke easily from the variant rule, I really liked the potential theme and construction and decided to commit to making it a standard for later- I just didn't expect to end up with 5 standards.

Puzzle #277 - Dividing Line (Nurikabe/Masyu)

I also submitted this second Nurikabe (like loop) and Masyu combination to GMP, but it was rejected on basis of type. Solve as a standard Masyu puzzle. Additionally, all connected groups of cells not on the loop must contain exactly one number, indicating the size of that group as in Nurikabe. The loop may not pass through numbers.

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I really, really like this construction- there's several steps I found really interesting while testing this puzzle, and of course the theme is striking.

Puzzle #276 - Chained (Cave)

This post is a bit different- no puzzle image, no interface link, just a link to where it's published on Grandmaster Puzzles. Most of my readers have probably already seen and solved this puzzle from a month ago. This blog is where I want to keep a record of all of my puzzles, and so it gets this post. Why now and not then? Simple, I had already planned for December 1st - 25th to be a variant series for numbers 251 - 275 and linking when it was first posted would have thrown off my numbering :P

GMP Submission #1 - Cave

I wasn't necessarily expecting this one to get accepted as the logic felt fairly plain to me with a fairly weak theme, but here we are. I tend to use diagonally touching clues in my Cave puzzles and this one was no exception- I have a few more puzzles waiting to be published in the future that I'm much more pleased with the construction of.

Which of course says a lot about them, because this one is solid!

Puzzle #??? - Excalators

I don't tend to make puzzles outside of grid-logic puzzles (and levels in puzzle games) but for Christmas, I stepped outside my comfort zone a bit and made my brother a variant on Escalators. Some of the clues are personalized towards things he would know that aren't common knowledge, though it shouldn't stop the puzzle from being reasonably fair with one lookup.

Link to a PDF of the puzzle

Also for the holidays, I made my sister a Minecraft adventure world, and my mom a series of puzzles I'll be posting later in the month. I also participated in the Puzzlers' Club Secret Solver event, and will post what I made for my solver once constructors are revealed in a week or two.

Puzzle #275 - In Absentia (Kakuro/Kropki)

Kakuro is kind of bland. Kropki isn't, in my opinion. Adding the dots and negative constraint to Kakuro proved to be a wonderful experience for construction- dead ends were immediately obvious, there were tons of highly restricted cells to work with and influence in many ways, and I even got to avoid cluing a bunch of cells directly.

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Oh, did I say I added dots? What happened to them 🙄

That's right, all dots are given. All 0 of them. Have fun, and happy holidays!

Puzzle #274 - Wander Wall (Meandering Ripple Effect)

When I was originally brainstorming variant ideas, I wanted to include Ripple Effect in some way. My first two ideas didn't go well- adding the restriction to Cojun or Makaro. My third idea of making a hybrid with Meandering Numbers didn't go much better, but when I revisited it with a better understanding of what the added implications were I managed to turn up this puzzle after a lot of testing dead ends. The solution to the puzzle should be a valid solution in both rulesets.

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I don't recommend trying to make one of these. I really don't.
Errata (2020): the puzzle originally had no solutions, now it has one.
Errata (2023): added 2 givens to improve solve path and remove alternate solutions I couldn't find.

Come back tomorrow for the final variant in this series- I'm really proud of the construction, even if it's not for everyone. Afterwards, I have some other holiday puzzle gifts and assorted other puzzles I have lying around to continue posting into the new year :)

Puzzle #273 - Five of a Kind (Fivecells/Pentominous)

Today's combination is one that's been done before with a lot of neat interactions- Fivecells and Pentominous. I wanted to try my hand at it and quickly decided not to pursue a symmetric theme in favor of some more interesting logic and a different aesthetic- I like how it turned out.

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Puzzle #272 - Filling Space (Aho Fillomino)

Aho is a puzzle genre so rare, that I actually couldn't find any rules page for it outside of puzz.link, nor could I find any examples but those in its database. It's a fun twist on Shikaku where regions with areas divisible by 3 must be L-shaped, while areas not divisible by 3 must be rectangular. I thought it could be fun to add the core restriction from Fillomino where regions of the same size may not share an edge.

So in summary: divide the grid into regions where each region contains exactly one circle. The area of the region dictates the shape it should take- an L* if it's divisible by 3, and a rectangle if it isn't. Regions of the same size may not share an edge.

*Unlike Sashigane, each end of the L may be any size. As an example, a 21 may be satisfied by cutting a 2x2 out of a 5x5 square, among many other possibilities.

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The coolest step during construction ended up just barely not working, with a second possibility I had overlooked. Thankfully the rest of the logic ended up working out better than I intended, again due to a missed possibility that had a neat step to eliminate. See if you can guess what I'm referring to!

Puzzle #271 - Secluded Hot Spring (Onsen/Country Road)

When I got around to trying to construct an Onsen puzzle with a Country Road variation (unused cells may not be adjacent across a region boundary), I knew I would need to make a larger puzzle to really use the ruleset to its potential.

So I did.

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The first few decisions I made while constructing (the numbers and the frame) ended up giving me some trouble later on. That said, when I testsolved the puzzle after finishing I found it to have some interesting interactions, and the variant rule came into play more than I thought it did from constructing.

Puzzle #270 - Starry Night (Maxi Loop/Double Back)

It's funny to think that this is my second puzzle utilizing Maxi Loop rules, and I still haven't constructed a vanilla example of the type. I've also never constructed a vanilla Double Back, the other genre today's puzzle must obey the rules of. It's not a difficult combination and I found the types worked together quite well to make a smooth solve path.

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Puzzle #269 - Constellation (Balanced Moon or Sun)

I've seen Moon or Sun puzzles where the clues must obey Masyu rules before, and thought I'd try for something a bit more original by having the clues obey Balance Loop rules. White circles (suns) will have the loop segments travel the same distance in both directions, and the black crescents (moons) will have the loop segments travel a different distance in both directions. There's some potential for very sparse and tricky puzzles with this combo, though I doubt it'll be seen anytime soon since neither genre is particularly common.

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Puzzle #268 - The Empty Space Above (Castle Wall/Yajilin)

Stop me if you've heard this one before: a puzzle constructor decides that Castle Wall should be combined with another puzzle type where you draw a loop that can't pass through clue cells that contain a number and arrow, also known as Yajilin. You might have heard of it.

However, I don't think I've seen the types combined in this way before- all clues are Castle Wall clues, and the loop must follow Yajilin rules where unused cells can't be adjacent. Note that unused/shaded cells are not counted as black walls, and so can be both inside or outside the loop. I was a bit surprised that this much empty space could be specified under these rules, and pleasantly so. I came very close several times before finding this arrangement which also solves well.

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Puzzle #267 - White Hole (Tasquare/Lookair)

While browsing genre lists to find interesting hybrids, I realized that both Tasquare and Lookair are puzzles based around squares of shaded cells, and that adding Lookair's primary constraint of same size squares being unable to see each other to Tasquare could lead to some very interesting interactions. Both types already have a lot of potential to fill large empty spaces, and combining the two only compounded this in some surprising ways.

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Puzzle #266 - Seaweed in the River (Norinori/Heyawake)

Believe it or not, I had actually thought about this variant series and done some brainstorming for ideas a few months ago, and adding the Heyawake three room restriction to Norinori was one of the ideas I was most looking forward to. Cut to a month or so ago, and some new Heyawake "river" theory is all the rage, regarding adjacent narrow rooms, and there's room for a play on words with this variant. Maintaining my desired theme proved challenging, especially while trying to close out the puzzle uniquely. Quite a rewarding process that I'm glad I committed to though!

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Puzzle #265 - Bowing In (Nuriboumaze)

As evidenced from the post title, this puzzle is a hybrid of Nurimaze and Nuribou, the latter of which is a type I've never constructed. For this Nurimaze puzzle, the final pattern of shaded cells should obey Nuribou rules- this combination was another that surprised me with some of its implications, and I'm very glad I switched the variation from the originally planned Cave (without numbers, so it would only add a restriction on shaded cells). And of course, both puzzle types beginning with "Nuri" is amusing, too.

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Puzzle #264 - Cyclone (Creek/Yin Yang)

I really like Creek puzzles, even though the type has a common complaint that implying shaded cells is too rare. So I applied Yin Yang rules to it to create a Creek puzzle where the solution will have all shaded cells connected, in addition to the standard unshaded connection. The final solution should both satisfy all of the Creek clues, and be a valid Yin Yang solution. Adding this simple restriction ended up being very powerful and fun to work with, and I hope you enjoy the same process of discovery I had while constructing this puzzle.

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Puzzle #263 - Clumps of Clay (Kurotto Stostone)

This was one of the variant ideas that I wasn't sure if it was going to work very well or not. It turns out that a Kurotto puzzle that has the added requirement that the shaded cells form a valid Stostone solution (without given regions) is actually incredibly fascinating. There are so many subtle bits of feedback between the two types that I found quite satisfying to uncover during construction. I hope you enjoy finding them too!

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Yeah, I know that's two Kurotto puzzles during this variant series. What can I say, the type can be tweaked in some really fun ways without much difficulty.

Errata: R7C2 has been changed from a 7 to a 5- I missed a possible connection from making both of those numbers the same, originally, and the puzzle had two solutions.

Puzzle #262 - Sea Serpent (Snake Aquarium)

As the post title indicates, this puzzle is a hybrid of Aquarium and Snake. The solution must meet all requirements of both puzzle types. I thought that this would be an interesting combination as there are a ton of Snake variants out there, and Aquarium was the obvious choice to pair it with as it also has outside clues. Some very different region layouts could lead to some very different logic to be discovered and I kind of hope someone else picks up on this combination in the future. Or I might push it farther, I'm not sure.

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Puzzle #261 - All Four None (Tatami Sashigane)

Funny story about this variant- I originally tried applying it to Tentaisho instead, and constructed 4 working puzzles (and 1 failed construction where I gave up on the variant rule). However... none of them needed the variant to be unique! Not even one!

So I switched to Sashigane and themed it on the number 4. Solve as a standard Sashigane, except there can be no gridpoints where 4 borders meet. I checked afterwards, and the variant is required- though it shouldn't be too tricky of a solve.

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The bottom left of this puzzle has been changed from its original version, as the original version had two solutions. That's what I get for slipping behind schedule, I guess- I'm a few days ahead at the moment.

Puzzle #260 - Close, But Not Quite (Knapp-Daneban Double Choco)

Knapp-Daneban is an interesting variation where all given numbers are off by exactly one. I thought applying it to Double Choco would be interesting, and made this puzzle with 10 different numbers. Getting some initial deductions proved quite challenging here. Another interesting interpretation of K-D Double Choco would be to have the regions be one cell apart from each other- I think it's been done?

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Puzzle #259 - Extensions (Multi-Numberlink)

So, Numberlink. A very tough genre to construct, and generally an easy one to solve... without a uniqueness proof. I think that this variation, where all instances of a number must be on the same line, normalizes all of these disparate challenges. I found it easier to construct, easier to prove unique, and harder to intuitively solve. How much of that is the specific puzzle and how much is the variation is an interesting question, that someone else will have to be the one to answer.

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Puzzle #258 - Crosswind (Crossing Nagare)

How many times has the first puzzle of a genre I've posted been a variant of that puzzle? I actually don't know. Anyway, here's a Nagare puzzle where the loop is allowed to cross. Note that crossing through the "wind" would not be allowed, as one of the crossing lines would not be pushed, and that crossing on a black arrow would also not be allowed, as it would then be exited in a direction other than where it's pointing.

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I think this variant is a bit more interesting than the standard type, though it does lose some neat directionality arguments from the fact that the loop can cross. In a standard Nagare, the two adjacent down arrows would be an instant contradiction!

Update: the original puzzle had 2 solutions, this has since been fixed.

Puzzle #257 - Downright Weird (Global Haisu)

Remember Haisu? Well, I had the weird idea to apply the room visit number rule to the entire puzzle as well- so all instances of a 1 must be visited before a 2, before a 3, etc. The implications are tough to grasp and I'm guessing heavily puzzle dependent, and there's room for at least another few in this variation before it starts getting stale. I definitely don't regret the construction attempt here.

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Puzzle #256 - Still Framed (Transparent Kurotto)

Fun fact about this puzzle: this was actually my second attempt at making a Transparent Kurotto, with the first coming back when I made the Yajikazu/Akari combo with bulbs on walls. Anyway, solve as a standard Kurotto puzzle, except clued cells can be shaded. It's a bit harder to construct a break-in with the variant rule and there are some fun implications to be found with it, and like most of these variations I hope to see them explored further as there's a lot of potential.

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I'm just now realizing this could be used for secret solver inspiration. I wonder if it will be?

Puzzle #255 - Cross Sums (Nuraf)

Today's puzzle is a bit of a weird one- it's a Nurikabe where the unshaded groups obey Araf rules, containing exactly two numbers with an area strictly between those two numbers. For another example of a Nuraf puzzle, check that link.

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I... don't understand this type as well as I might like. It's quite interesting and there's a good chance of revisiting it in the future since there's a ton of potential here. Though there's nothing wrong with an easier elegant puzzle sometimes.

Puzzle #254 - Return to Diamonds (Partial Kropki)

When I first constructed some Kropki puzzles, I bemoaned the "all dots are given" constraint and how it prevented a nice aesthetic theme and often broke intended logic in the fill.

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So here's a variant puzzle which solves as a normal Kropki, except not all dots are given. Somehow this theme ended up both working well logically and aesthetically, with anti-symmetry to boot!

Puzzle #253 - Seeing Double (Double Nanro)

I often struggle to construct puzzle types with regions like Nanro- something about drawing the regions and giving clues just doesn't click right with me. That said, when I set out to make this run of variant puzzles I knew I had to try Double Nanro- solve as a regular Nanro, except instead of having exactly N instances of N in a region, have exactly 2 connected groups of N in a region. So a region with a 2 would contain four 2s, in two groups of two. This was a really fun variant to work with, even if it's not difficult to run into constructing dead ends. I'd love to see more of these, as there's definitely some interesting logic I didn't tap here!

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Puzzle #252 - Prime Differences (Doppelblock, Prime)

Logic Showcase 20 recently concluded on the Puzzlers Club Discord, which tasked participants with making a number placement puzzle with a non-standard set of digits. The four entries used Fibonacci numbers, prime numbers, inverses, and complex numbers- the puzzle that used inverse numbers was really neat and deserved the win over my prime Doppelblock, which follows standard rules except using the first 6 prime numbers instead of 1-6.

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It's probably easier to solve than it was to make.

Puzzle #251 - Opposition (Non-Consecutive Skyscrapers)

I'm going to be trying to make daily puzzle posts during December again, and specifically I'll be aiming for a different variant puzzle every day through Christmas. Will I succeed? I hope so! First up is a puzzle I prepared earlier, a non-consecutive Skyscrapers puzzle. Solve as a standard Skyscrapers puzzle, with the additional rule that numbers differing by one may not be orthogonally adjacent. This 6x6 turned out very difficult to construct, after a completely unfair 7x7 and several failed attempts on larger grids.

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(thanks to gravel and Bryce for pointing out the original 2 placements left 2 solutions. The puzzle has been fixed twice and definitely has one solution now.)

And for fun, here's the unfair puzzle. If you're just trying to find *a* solution it should be doable, but proving it's the only solution required me to make several 3-level case distinctions. It's an elegant design, however, and honestly surprising that it works.

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