Spontaneous Saturday 7/12: Conceptis Puzzles part 2

Screen Shot 2014-06-14 at 1.19.55 AM

For this Spontaneous Saturday, I shall expand on my previous post about Conceptis puzzles by talking about 5 puzzles that I hadn’t covered previously: Tic-Tac-Logic, Hitori, Fill-a-Pix, Pic-a-Pix, and Nurikabe.

11/2/15 EDIT: I just realized that 1 has a link to 2 but 2 doesn’t have a link to 3. Let me fix that.


While it is a puzzle inspired by tic-tac-toe, it is not the tic-tac-toe we all know. No, instead of trying to get three in a row, the objective is to not get three in a row. Although, that’s only part of the objective. The objective in full is to fill the board with X’s and O’s to fulfill the following conditions:

  1. There must be no more X’s than O’s.
  2. There must be no more than three consecutive X’s or O’s down a column or row.
  3. No two rows or columns can be completely alike.

Quick review exercise: Figure out everything wrong with this incorrectly solved puzzle.
Screen Shot 2014-07-12 at 2.54.49 AM


From the website (since I can’t word it any other way): “Each [Hitori] puzzle consists of a square grid with numbers appearing in all squares. The object is to shade squares so:

  • No number appears in a row or column more than once.
  • Shaded (black) squares do not touch each other vertically or horizontally.
  • When completed, all un-shaded (white) squares create a single continuous area.”

Basically, in Hitori, you have two options: circle or shade. Numbers can only be shaded if they appear twice or more in a row or column and if adjacent numbers are unshaded. There are three main patterns I use to crack at Hitori puzzles: the Triplet, the Stalker Duo, and the Sandwich. Here are all three of them, presented in one image:
Hitori patterns

  • Triplet: If three of the same number appear consecutively in a row or column, shade the outer two and circle the middle one.
  • Stalker Duo: If two of the same number appear consecutively in a row or column with a non-adjacent one of the same number, shade the non-adjacent one.
  • Sandwich: If two of the same number surround a different number in a column or row, circle the surrounded number.

These are 100% guaranteed to yield logical results, but they aren’t be-all-end-all. Just keep the three tenets in mind when solving the rest of the puzzle.


In Fill-a-Pix, there are numbers. Lots and lots of numbers. What do these numbers mean? They represent the number of shaded squares surrounding them. Think of it like Minesweeper, but without the mines. It is really simple. Like, unbelievably simple. It’s still fun, though, because unlike some puzzles (see previous installment), it actually requires thinking. Here, I’ll include a solved puzzle to alleviate the brevity of this description.
Screen Shot 2014-07-12 at 3.35.39 AM


As (subjectively) far back as 10 years ago, there was this one puzzle game I happened upon called Picross. It was basically B/W Pic-a-Pix: each row/column is marked with clues that indicate how many squares must be highlighted, and in what pattern. Here is a sample B/W puzzle:
Screen Shot 2014-07-12 at 3.49.05 AM
and here is a sample color puzzle:
Screen Shot 2014-07-12 at 3.50.43 AM
So, for instance, column 5 of the colored puzzle must be filled in the following manner: 1 red, 4 blue, 2 black. These puzzles were really confusing to me at first, but there is an algorithmic way to approach it: use the size of the grid and the clues to chip at the puzzle little by little until the full image is created. Use the following equation:

Number omitted = Grid dimension (height or width) – ∑ clues

where ∑ clues is determined in the following manner: Add the numbers in the row/column clue. For every consecutive clue number of the same color, add an extra 1.

Using this formula, if the Number omitted (we’ll call it N) is 0, you can complete the row/column without hesitation. Consider the B/W image shown earlier. Column 4 yields an N value of 0, so let’s fill it out real quick.
Screen Shot 2014-07-12 at 3.59.09 AM
But, if N is not 0 and is no greater than any of the clue numbers, you can try to complete the clue, but you must skip N tiles (or the clue number, whichever is less) per clue while filling it in. This time, I will use the color puzzle as an example; column 5 has an N value of 3, columns 3 and 4 have N values of 2, and row 6 has an N value of 1. So, we can incompletely fill these fields out.
Screen Shot 2014-07-12 at 2.26.05 PM
Sometimes, chipping away at the puzzle like this may lead to odd breakthroughs (for example, row 6 now has 3 red tiles instead of 2, thanks to the column hints), and that’s what it’s all about. All in all, Fill-a-Pix requires math skills (I sometimes use a calculator when doing weekly Fill-a-Pix) and plenty of patience. But, I wouldn’t have it any other way.


Ah, good old Nurikabe. Yes, good old chances-are-if-it’s-Medium-I’ll-have-to-guess-my-way-out-of-it Nurikabe. Wait, what? Sorry.

Once again, I’ll quote the rules from the website since it’s hard to explain. “Each [Nurikabe] puzzle consists of a grid containing clues in various places. The object is to create islands by partitioning between clues with walls so:

  • Each island contains exactly one clue.
  • The number of squares in each island equals the value of the clue.
  • All islands are isolated from each other horizontally and vertically.
  • There are no wall areas of 2×2 or larger.
  • When completed, all walls form a continuous path.”

Basically, the main things to keep in mind are: isolated “islands” with only one clue each, continuous path of black with no 2×2 squares, and the number of squares per island should be equal to the number within the island.

Review exercise: Compare the following puzzle to its solution:
Screen Shot 2014-07-12 at 3.20.32 PM Screen Shot 2014-07-12 at 3.21.24 PM


Copied from the previous installment: “Overall website rating: 9/10. The only thing I could ask for Conceptis to change is to either set Sound to “Off” by default or to allow account-based defaults so that they apply no matter the device used (my computer’s data got wiped once and I had to turn the sound off again for every single puzzle). Also, more free-to-play puzzles would be nice. (Come on, just one per category per week?)”


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