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Wednesday, January 30, 2013

Dominoes 1

I wish I had a way to link to an Excel spreadsheet in this blog, but I don't see one.  Guess you'll just have to print this one out.

Monday, January 28, 2013

Dominoes rules

A set of dominoes has been laid out in a grid and the edges erased.  You must determine where the edges go.  The solution is unique.

Here is a sample and its solution:

Most puzzles will include a set of dominoes to the side for checking off used dominoes.  Unfortunately, I have not found a completely suitable domino applet yet. has one, but it doesn't support the double nine dominos that I used for the first puzzle.

Edit: I know it has been years since I have posted anything on this site, but I decided to dust it off today and look at it.  When I did that, I noticed that there is a bit of a flaw in my sample puzzle, depending on your definition of the rules of a unique solution.  According to my definition, it is a flaw.  

The solution is not unique, in that everything can be solved uniquely up until the last four dominoes in the upper right corner.  The way I have the solution posted above is not a unique solution, as the 3/2, 3/1, and 2/1 dominoe can be moved around to provide another solution. In my definition of unique, this is not allowed and the mistake was mine as I did not intend the puzzle to work out this way.  However, the 1/1 domino can also be positioned vertically instead of horizontally, which leads to the following solution:
Working this way, we can see that this does force a unique solution.  So here's the rub: Some puzzlers consider the unique solution to be a condition that must be followed during the solving process, rather than a constraint on the solution, if that makes any sense.  The logic proceeds like this:  I have reached a point where I have to make a guess.  If I choose guess number one, the logic chain proceeding from that guess allows multiple solutions.  If I choose guess number two, the same thing could happen again.  Repeat until you get to the final guess.  This guess does lead to a unique solution.  Therefore, that must be the correct guess.  I don't really like this kind of puzzle.  For some reason, it just seems like the puzzle is cheating.  I like my puzzles to have one solution, and one solution only.  In fact, it wouldn't even be appropriate to say that my puzzle has a unique solution, because unique implies that one solution stands out different from the rest.  I would define the solution to my puzzles to be the solution.  I will leave this sample puzzle in the blog as it is for demonstration, but if you ever find one of my puzzles with a non-unique solution, please bring it to my attention, because that would've been an error in the design process.

Akari 1



Akari Rules

Akari is a Japanese surname meaning "light."  The puzzle is also called Light-Up, and for obvious reasons once you try one.  Here are the rules.

1.The puzzle consists of a grid with some black cells and some white cells.  Some of the black cells contain numbers.
2. Light bulbs must be placed into the white cells.  The numbers in the black cells indicate how many horizontally and vertically neighboring cells contain light bulbs.  Black cells with no numbers can contain any number of neigboring bulbs.
3. Light bulbs illuminate all the cells in the row and column they are in, up to the edge of the grid, or to a black cell, whichever comes first.
4. No two light bulbs can illuminate each other.

Below are a sample puzzle and its only solution.

Sunday, January 27, 2013

Nurikabe 4

It's been a long time (almost two years), but I've started creating puzzles again.  Maybe this time I'll be able to stick with it.

Friday, January 28, 2011

Slitherlink 3

I kind of have a soft spot for Slitherlink.  It was the first of the Nikoli type puzzles I was introduced to (besides Sudoku, Kakuro and Battleships).

Nurikabe 3

I was experimenting with different grid sizes and came up with this.  I suppose it would've worked just as well if it was stretched vertically rather than horizontally, but it just felt more stable like this.

Wednesday, January 26, 2011

Chocona 2

Nurikabe 2

I'm keeping with the golden ratio motif, but I've increased the size of the board to 15 by 24.  And I've included a hefty 27-cell "island" in the puzzle. 

Masyu 2

I was experimenting with golden ratios and trying to make a board size that is the most aesthetically pleasing.  Since the golden ratio is approximately 1:1.61803399, my choices were somewhere between a board size of 100,000,000 columns by 161,803,399 rows or 2 columns by 3 rows.  I settled for a size that should take fewer seconds to solve than the total number of atoms in the universe.  I thought 10 columns by 16 rows makes a nice looking board, and you should be able to solve it in just a few minutes.

Edit:  I removed a pearl that was unnecessary to arrive at a solution.  I updated the Puz Pre link, too.  I'm sure there's more pearls I could remove, but I'm not that good at getting it to a bare minimum yet.  I just happened to get lucky with the one I took out.

Monday, January 24, 2011

Slitherlink 2

I finally got around to creating another slitherlink.  I wanted something a little more challenging than my first, and something with a nice aesthetic look to the starting clues.  What came out was this.  Just to forewarn you, this one is not easy.  I actually felt a little dirty for letting this one loose in the world.

Chocona 1

This one is pretty easy, and there are a lot of givens.  I hope to get better.

Chocona Rules

I think this puzzle shows some promise to be an interesting puzzle type.  I like how the logic seems to work more towards "Where can't the black squares go?" rather than "Where can the black squares go?"  It works thusly:

  1. Some of the cells must be painted black.  A number in a heavily bordered region indicates how many cells in that region must be painted black.  A region with no number can have any number of black cells, including zero.
  2. The black cells must create only rectangular or square areas.
  3. The rectangular areas may include cells from different regions, and most likely will.
  4. Two different rectangular areas may not touch along edges.  They may touch at corners, though.  (Thanks, Marcin, for pointing out this missing rule.)

Check out the sample below.

You'll note that there is no requirement for all the painted cells in any particular region to be connected.  

Wednesday, January 5, 2011


Yeech.  I hope this post works okay.  I've created a monster of a LITS puzzle and now my Internet connection is all wonky.  I've got the images saved, but the Puz Pre link may give me issues.  Anyways, this puzzle is probably the hardest I've created so far.  Get ready to put your thinking caps on.  You'll definitely need to open this in its own window.


Another tip:  If you go to the Puz Pre link, Go to the Display menu, and change the Cell size to Small or Ex. Small to see more of the puzzle at once.  It also helps with making the borders between regions appear thicker and easier to distinguish between them and the thinner grid lines.

Tuesday, January 4, 2011


LITS Rules

LITS earned it's name based on the 4 pieces that are used in the puzzle.  The L-shaped tetromino, the I-shaped tetromino, the T-shaped tetromino, and the S-shaped tetromino.  The square tetromino is not used for reasons you will see below.

Here are the rules.

1.  Each region in the grid must contain exactly one tetromino of edge-connected cells.
2.  No tetromino in one region can touch another similarly-shaped tetromino in another region along a cell edge.  (This includes rotations and reflections)
3.  A solved puzzle can have no area of 2x2 black cells anywhere.  (Even if the cells come from different regions.)
4.  All black cells must be connected together through their edges.

Stay tuned for LITS Puzzle no. 1!

Tuesday, December 28, 2010

Nurikabe 1

Here is a Nurikabe for you to enjoy.  Not too hard, not too easy.

Nurikabe Rules

A Nurikabe is a Japanese spirit that manifests itself as a wall to impede travelers walking at night. The puzzle Nurikabe is so named because the object is to figure out where the black cells are placed based on the clues.  I guess the black cells are the Nurikabe spirits.  Here are the rules and a sample puzzle:

1. Each number in the grid indicates a region of edge-connected cells of exactly that number.  No two numbered areas can touch except at corners.  Each number will be a part of exactly one region
2. Each numbered region is surrounded by either the walls of the puzzle, or black cells.  All black cells must be edge-connected together to form one contiguous region.
3. No numbered cells can be painted black.
4. No black cells can be connected together to form a 2x2 area of black cells in any part of the grid.

Friday, December 24, 2010

Masyu 1

Here is my first Masyu puzzle.  It moves along pretty quick in the beginning, but I think you'll find a little thinking is required towards the end.

I do realize there are quite a few more givens than you would normally find in this kind of puzzle, but I haven't yet learned how to pare them down to bare minimum.  Give me time.  Hopefully, you'll still find it fun.

Masyu rules

Masyu (also sometimes known as pearls) belongs to the same family as Slitherlink.  They are both puzzles where you must use the clues to draw a single connected loop.  Here are the rules:

1. Use the clues to draw a single, connected loop that does not cross or branch off.
2. Lines must pass through the black circles (or pearls), and must turn at a 90 degree angle within the pearl.  The lines coming out of the pearl on each leg of the angle must continue straight for at least one square.
2. Lines must also pass through the white circles (or pearls), and must go straight through the pearl, but must make a 90 degree turn on at least one of the squares adjacent to the pearl.
3. Not all squares in the grid are required to be filled, but every square with a pearl will have a line through it.

Here's an example:

Wednesday, December 22, 2010

Fillomino 2

Ok, my first attempt at a fillomino was just, shall we say, lame.  Hopefully this one is a little better.  For one thing, it's the standard 10 x 10, and for another, it's got some pretty large ominoes in it.  I thought these would be easy to make, but as it turns out, they can be a headache to make while still making the starting pattern look nice.  Still, I had fun designing it.  Enjoy!

Tuesday, December 21, 2010

Fillomino 1

And here is the Fillomino I created.  It's a tiny one.  I promise they will get bigger.

Slitherlink 1

And welcome to the first actual puzzle for you to solve.  Enjoy!

Monday, December 20, 2010

Fillomino Rules

Fillomino is so-named because the task is to fill a grid with polyominoes.  Polyominoes are basically dominoes of different sizes.  They can be any size from one to the size of your grid, though that would make for a very uninteresting puzzle.  The rulese are:

1. A polyomino consists of a series of edge-connected squares.  When the puzzle is solved, each square in a polyomino will contain a number that is equal to the number of the squares in the polyomino.
2. No polyomino touches another polyomino of the same size along an edge.  They may touch at corners.
3. Every square in the grid must contain a number and be part of a polyomino.
4. Some polyominoes may have no clues given.  They still must follow the rules above, though.

Sample and solution follows


Slitherlink Rules

Slitherlink is probably one of the first Nikoli puzzles I discovered that did not originate in America.  Kakuro and Sudoku both originated with Dell Pencil Puzzles as Cross Sums and Number Place before they traveled to Japan and back again with the Japanese names.  But, this is about Slitherlink, not those. The rules are summarized below.

1. Draw a single connected loop between the dots that does not touch or cross anywhere in the grid.
2. Lines may only be horizontal or vertical.
3. Numbers indicate how many sides in the imaginary square surrounding that number that the loop passes through.
4. Unnumbered squares may contain any number of lines surrounding the square.

An example with its solution is shown below.

There are many strategies and patterns that can be used in solving Slitherlinks.  Perhaps the most well known are the side-by-side 3's, and the corner 3's as well as what I call 'cascading 2's', which is what happens when there is a series of 2's in a diagonal.  Really clever puzzle designers can also force the loop to take a path where there are no numbered clues, but bounce around from dot to dot simply because there is no other path to take.  The possibilities are endless, and even after many years of solving, I'm still learning new strategies.

Rules and some cool links

After posting my first two puzzles, I realized that I do not have a rules page like many others do.  I'm going to go ahead and create some rules pages and provide links in all my puzzles to them, but I also encourage you to check out some other puzzle creators' rules pages, not only because they can probably write clearer rules, but also because you need to see their puzzles as well.  I will put those links in the sidebar to the left, or right, or wherever they fit best.

Also, I am going to link to a Japanese page that provides an awesome puzzle editor.  Don't worry, they provide an English page.  Not only does it make it easier to solve these puzzles, but it makes them a cinch to create.  I mean, there's still all the work involved in coming up with an idea, implementing it and test solving, but you sure do save on paper.  And that's a very green thing to do. 

Welcome to Puzzlepalooza!

I have been a fan of Nikoli puzzles for some time now.  I've even ordered one of their Penpa Puzzle Mix books and have killed many rubber trees erasing and fixing mistakes, even as the pages fell out and drifted peacefully away to some blissful puzzle afterlife.  Of course, the Internet is a never ending supply of challenging puzzles, and you don't have to worry about your web pages falling out (although I've never had my Penpa book throw up a flashing page congratulating me on being its 1 millionth reader).  I've cruised several puzzle pages lately and it seems to me that the creators seem to have almost as much, if not more fun, creating the puzzles than it gave me to solve them.  So, I decided to give puzzlesmithing a try myself.  After much head scratching, crying, praying to the Puzzle Gods and presenting the required virgin paper sacrifices (good thing they were already clad in pure white), I present my first two self-made puzzles; a Slitherlink and a Fillomino.  The Fillomino is a small one and shouldn't present too much challenge, but the Slitherlink is a standard 10 x 10, and although it is not an extremely difficult one, it has its moments.  Feel free to comment, but do not post spoilers and please go easy on me; these are my first creations and they're shy little creatures.  Big, nasty comments will scare them away and likely prevent any future puzzles from coming around.  Enjoy!