Puzzle 372: Double Choco + Compass

It's been a while!  I burnt out after doing the Genre Spotlight series for a year, and then all my puzzle writing energy went toward LPO 2026.

Recently, I've been playing the new puzzle game The Artisan of Glimmith which, given that you're reading this blog, comes highly recommended.  This game combines several common region division constraints and clues, just like Islands of Insight did for shading genres.  My playtime with the game almost certainly inspired this mashup.

Rules: Divide the grid into regions of orthogonally connected cells, each containing a connected group of white cells and a connected group of grey cells.  Within each region the shape of the white cells is identical to the shape of the grey cells, allowing rotations and reflections.  

Additionally, some compasses are given in the grid.  A number in a compass indicates how many cells belong to its region that are further in the indicated direction than the compass itself.  A region may contain zero, one, or multiple compass clues. 

Online interface (Penpa)

 

Puzzles 368 - 371: Caves from Mustang Math 2025

I've continued to supply puzzles for the Mustang Math Tournament!  While MMT is primarily a math contest for middle school students (mostly written by high school students), there is one round every year which introduces a pencil puzzle genre.  In previous tournaments, we've covered Fillomino, Double Choco, and Slitherlink.  We give students an overview of the rules, a sample puzzle, and some variants, and ask them to solve as many puzzles as possible.  Some years are harder than others (the Double Choco round in 2023 was particularly nasty...) but we try to make the puzzle set accessible overall, with a few hard puzzles sprinkled in because I can't resist.

Last year, we decided to go for Cave.  We explicitly gave "no checkerboard" as a rule rather than something students needed to figure out for themselves.  Overall, the Cave round seemed to be easier than the Double Choco round from 2023, but harder than the Slitherlink round from 2024, which is not surprising.

I wrote most of the puzzles for the round, with Pranshu (a high school junior at the time) supplying the remaining grids.  Each section had a particularly tricky puzzle at the end, much harder than the rest of the set.  Here are those capstone puzzles; if you want the full set, let me know!

Puzzle 367 (Ice Walk (Hex, Bouba))

To close out the year, here's an Ice Walk on a hex grid.  This puzzle may not use loop closure that much, but the clue interactions are still surprising.  Here's to 2026 and beyond!

Rules:  Draw a loop through the centers of some cells which passes through each numbered cell. Two line segments may intersect each other only on icy cells, but they may not turn at their intersection or otherwise overlap. The loop may not turn on icy cells. A number indicates how many cells make up the continuous non-icy section of the loop that the number is on. 

Additionally, all turns must be "bouba" (i.e. all angles in the grid must be 120°.)

Puzzle 367 (Penpa)

 

Puzzle 366 (Tapa (Line))

Tapa (Line) puzzles tend to be quite difficult, because the Line restriction creates many unexpected and sometimes scary consequences.  This puzzle was specifically designed to flow nicely and be fairly easy overall.

Rules: Classic Tapa rules apply.  Additionally, no four consecutive cells in a row or column can be shaded.

Puzzle 366 (puzz.link) 

 

Puzzle 365 (Quad Tapa-Like Loop)

This is the second puzzle I made for WPC "prep".  Tapa-Like Loop is pretty cool.  Quad variants are usually pretty scary, but this one isn't too bad.

Rules: Classic Tapa-Like Loop rules apply within each quadrant.  Additionally, the contents of row / column pairs adjacent to gaps between the quadrants are exact reflections of each other, including loop segments and empty cells.  For example, the bottom row of the top-left grid is a mirror image of the top row in the bottom-left grid.

Puzzle 365 (Penpa)

 

Puzzle 364 (Kakuro (Star Battle))

This puzzle was made for WPC "prep" (the word "prep" is in quotes because I didn't attend myself).  It combines Kakuro and Star Battle in a very natural way, and I'd like to see more of the type.  That said, this puzzle is pretty tough, so beware.

Rules: Place the indicated number of stars per row and column so that no two stars touch, even diagonally. Then enter digits 1–9 into all remaining cells of the grid so that no digit repeats in any of the “words” across and down. Clues denote the sum of digits in each of the words. Cells with stars should not be counted into the sums.

Puzzle 364 (Penpa) 

 

Puzzles 362 and 363 (Slitherlink)

Here are two Nikoli-style Slitherlink puzzles on 10x18 grids.  These are always more difficult to construct than I expect.  It's pretty easy to make a puzzle with lots of easy steps, but it's much harder to create one which feels intentional.  I also tend to force linear solve paths in my puzzles, so when constructing a Nikoli-style grid, those intentions must be thrown out the window.

I think both puzzles before are successful attempts at the style, particularly the second one.

Puzzle 362 (puzz.link)

Puzzle 363 (puzz.link)

 

Puzzle 361 (Sus-Shikaku)

This puzzle is a Sus-Shikaku, a variant invented (?) by Prasanna Seshadri for last year's Puzzle Ramayan contest.  Apparently, this clue pattern was quite similar to one of the grids on the actual contest.  Regardless, this one is pretty tough.

Rules: Standard Shikaku rules, with a twist.  Divide the grid into regions so that each region contains one circle.  Regions containing black circles are still rectangular, but regions containing white circles are not rectangular.  Numbers still indicate the area of the region contained in the clue. 

Puzzle 361 (Penpa)

 

Puzzle 360 (Yajilin)

The next few posts on here will be reposts of various puzsq puzzles I've written this year.  I didn't want these posts to "dilute" the Spotlight (whatever that means), but now that the Spotlight is over, there's no reason not to cross-post them here.

First up, a Yajilin from way back in January.  At the time, I was messing with Cross+A generation, and wanted to see if it was possible to construct a symmetric Yajilin faster than Cross+A could.  The answer was "yes", although cspuz ended up being really helpful with the ending.  I'm super happy with how this one turned out.

Online interface (puzz.link)

 

Genre Spotlight 70: Trapezoids (Puzzles 358 and 359)

For our last spotlight (at least on a regular basis), I spent a long time thinking about what genre to do before realizing that we hadn't had a non-square grid yet.  (Tawamurenga doesn't count.)  Here's my opportunity to fix that!  This genre is Trapezoids, originally invented by Dan Adams in 2016.  It's a genre that only works on triangular grids, using that geometry in an interesting way.

Rules. Shade some cells black.  Shaded cells must be in clusters of three, forming trapezoids.  Trapezoids may not touch orthogonally.  All the unshaded cells must form a single connected group.  Each number indicates the number of shaded cells in the (up to six) cells surrounding the clue.

            

Small note: Dan's original puzzles don't seem to have any clues along the border of the grid.  I found border clues easier to work with, so added them into my constructions. 

Genre Spotlight 69: Key West (Puzzles 356 and 357)

Only two more left!  Not sure what I'll do for the last one; probably nothing special, to be honest.  Also, if you're thinking "wait, wasn't dj close to 400 puzzles before?", I realized yesterday that the numbering has been wildly off since May!  Whoops.

For today's genre, we've got a type that is hot off the pzprxs presses!  This type is Key West, first appearing way back in Puzzle Communication Nikoli 53.  Upon reading the rules, your first impression may be "wow this is very similar to Sukoro".  Indeed, the two genres share many common structures.  But the ruleset here is different enough to provide an alternate feel.

Rules: Place a number between 0 and 4 in every island, and draw orthogonal bridges connecting them. Orthogonally adjacent islands cannot have the same number. Numbers indicate how many bridges are connected to this island. All islands with a number above 0 must be connected into a single network.

       

Genre Spotlight 68: Oasis (Puzzles 354 and 355)

Today's genre is Oasis, a neat shading type invented by Matej Uher for WPC 2016.  I've been long scared of this type and never really attempted it.  I'm glad I gave it a go, it's much more reasonable than anticipated!  Still not easy, though....

Rules: Shade some cells so that no two shaded cells are orthogonally adjacent and the remaining unshaded cells form one orthogonally connected area. No 2x2 area may be entirely unshaded. Cells with circles cannot be shaded. A number in a circle indicates how many other circles it could reach by traveling only through empty, unshaded cells.

          

Genre Spotlight 67: Turnaround (Puzzles 352 and 353)

Oh no, two loop genres in two weeks?  Who have I become?

Today's genre is Turnaround, a puzzle type by Indonesian constructor chaotic_iak.  It is similar to a few other genres, mainly Inaba's Pearl Loop, which count loop turns near given clues.  

Rules: Draw a non-intersecting loop through the centers of some cells. A number indicates how many times the loop makes a turn within the three-cell portion of the loop with the clued cell in the middle.

             

Genre Spotlight 66: One Point Loop (Puzzles 350 and 351)

For today's genre, we have an Inaba type called One Point Loop.  The ruleset seems strange at first glance, but it has an equivalent interpretation that is much easier to think about when solving.  Like similar genres which only have one clue type, it takes some finesse to make interesting deductions happen, and moving clues around can seriously damage previous logical steps.  But this genre is fun to solve!  It feels like a version of Every Second Turn that has a bit more friction.

Rules: Draw a loop on the dotted lines passing through all black circles.  Each segment of the loop must contain exactly one circle, possibly at one of its endpoints.

           

Genre Spotlight 65: Trixo (Puzzles 348 and 349)

Before beginning this post, a small update.  Currently, we're on entry 65 -- it's been a long ride!  However, all good things must eventually come to an end.  I always planned for this series to last only a year or so, and it'd be good to end on a nice, round number.  The last entry of the Spotlight series will be Entry 70.  (This means that the last post will be in mid-December.)

Today's genre is Trixo!  This type was invented earlier this year by PuzSQ/Discord user xetto.  It's an interesting type!  Feels Inaba-like, in a way.  (Though I said that about Corner Disorder last week.  Shrug.)

Rules: Place some shaded trominoes onto the grid to form a single diagonally connected network.  All clued cells are shaded.  Cells marked with a "╳" must touch another tromino diagonally.  Cells marked with a "◯" must not.

          

Genre Spotlight 64: Corner Disorder (Puzzles 346 and 347)

Today's genre is a bit different than usual, because it's a type I just made today (Sunday)!  More specifically, the idea for this ruleset came while playing with a different genre called Quarry.  This type, from michael3.14 in the CTC server, has the same rules for black and white squares, but also permitted unclued regions which satisfied certain properties.  These unclued regions felt tough to force because of the way the white circles work.  What if we removed the unclued regions, then, and loosened the remaining rules a bit?  

This is what I came up with.  It may not be in the spirit of the Spotlight series, but I spent enough time constructing these (and fixing some uniqueness issues in my first attempt) that I felt it was worth posting.

Rules: Divide the puzzle surface into rectangles, each containing exactly two circles.  Black circles must be located in a corner of their region.  White circles must not be located in a corner of their region.  Gray circles may be of either color.

           

Genre Spotlight 63: Bunnyhop (Puzzles 344 and 345)

This post was originally about a different genre, but constructing puzzles in that type proved difficult, so I pivoted to a different type.  As it turns out, this one is also difficult to construct.  You know it, you love it or hate it, it's Bunnyhop!  Invented by Hempuli, known for his hit game The Plumber Thing and literally nothing else.

Rules: Draw lines along the edges of cells to form a loop. Every line segment goes through a cell, connecting two corners located along the same edge. Every cell must be visited exactly once. The loop cannot branch off or cross itself.  Black cells cannot be visited.

                

Genre Spotlight 62: Kazunori Room (Puzzles 342 and 343)

This week, we have a Nikoli genre called Kazunori Room.  This type has actually been implemented in puzz.link for a while!  It's an interesting type.  I'm not quite sure if this genre needs an extra rule or clue type somewhere, but for now, here you go.

Rules: Place a number from 1 to N into each cell so that each region contains each number from 1 to N exactly twice each, where N is half the number of cells in the region. Two numbers of the same value within a region must be orthogonally adjacent. No 2x2 area may consist of cells which all contain the same number. Clues represent the sum of the numbers in the cells they touch.

               

Genre Spotlight 61: Martini (Puzzles 340 and 341)

Today's genre is a shading type called Martini.  It appears on puzz.link but I'm otherwise not sure where the type originates.  Perhaps it's a Nikoli Omopa?  Regardless, it's an interesting type that allows for some interesting interactions.

Rules: Shade some cells such that all shaded cells within a region form a single orthogonally connected group. Shaded groups may not be orthogonally adjacent, but must all form a single diagonally connected network. Cells with black circles must be shaded. Cells with white circles must not. A number in a white circle indicates the total number of circles that are in its orthogonally connected area of unshaded cells. 

          

Genre Spotlight 60: Mukkonn Enn (Puzzles 338 and 339)

Today's genre is Mukkonn Enn, first appearing in WPC 2017 as an instructionless puzzle. Prasanna Seshadri refined the genre (e.g. made it a full loop) and changed the name to Mukkonn Enn for its 2022 GrandmasterPuzzles debut.  I've seen this type for a while but never got around to making one.  Acting on those hunches is what this spotlight series is about, right?

Rules: Draw a single, non-intersecting loop that passes through the center of all cells, including clue cells. Each clue cell is divided into four sections. If a number is present in a section and the loop travels in that direction, then the number represents the length of the straight loop segment in that direction, measured from the clue cell to the cell where the loop turns. If the loop does not travel in that direction, then the number means nothing.