Tricky Logic Puzzles for Adults

my upcoming book

Posted by Steven Clontz on January 17, 2020

I’m very excited to announce that my book of logic puzzles, including 25 “cryptic” or puzzlehunt-style puzzles, will be published in Feburary!

book

It will be available on Amazon and wherever else books are sold.

Thanks to Andrea Blumberg, Bryan Clair, Phillip Clontz, Tracy Cobbs, Jenn Dumont, Julie Gaddy, Steve Gaddy, Eric Harshbarger, Charles McPillan, Erin McPillan, Trent Webb, and my wife and daughter for their support in the writing of the book. And special thanks go to Andrea, Bryan, Eric, and Jenn for letting me adapt four great puzzles of theirs for the book!

Sample Puzzles

As the release date approaches, I’ll be sharing some of the kinds of puzzles I hope you’ll enjoy in the book.

Nonogram

First up, here’s a nonogram, also known as color-by-number or Picross. The puzzle below was one of a few cut from the final manuscript to get the page length (and price!) down, but hey, that means I can share it here instead! Here’s an excerpt from the book explaining them, and a completed example from Wikipedia.

Nonogram puzzles are known by a wide variety of names: Picross, Paint-By- Number, Griddlers, Logic Art, and many more! Solving (and designing!) puzzles are a particular joy, because rather than the final answer being an arbitrary grid of numbers or symbols, the end result is a pixelated image. Half the fun is figuring out what you’re drawing as you solve.

In a nonogram, each cell of the grid will either be left blank, or filled-in. To solve, consider the numbers at the boundaries. Each number represents a continuous block of filled-in squares, ordered top-to-bottom or left-to-right.

“Level Up”

(Nonogram Javascript library credit: https://handsomeone.github.io/Nonogram/)

Calcudoku

Calcudoku puzzles, also known under the (trademarked) name KenKen, are a fun blend of logic and arithmetic.

A Calcudoku puzzle uses the numbers 1 through 4 for a 4 by 4 puzzle, 1 through 5 for a 5 by 5 puzzle, and so on. Like Sudoku, each row and column must contain each of the numbers for the puzzle exactly once (creating what mathematicians call a Latin square). But since, unlike a Sudoku puzzle, none of the numbers are provided, you’ll need to use logic to place the numbers in each cell according to the clues given in each “cage”. Addition \((+)\) or multiplication \((\times)\) clues describe the sum or product of the caged numbers. Subtraction \((-)\) or division \((\div)\) clues describe the difference or quotient of the larger number by the smaller number in the cage (which always has two cells). Numbers can be repeated within a cage, as long as they don’t share a row or column.

Since the below example is a \(7\times 7\) grid, it should be filled using the numbers 1 through 7. The book contains Calcudoku puzzles between \(4\times4\) and \(8\times8\). To print and enjoy, the below image links to a PDF.

calcudoku

Logic Grids

I couldn’t resist including a few classic logic grid puzzles into my book!

Logic Grid puzzles are perhaps the purest type of logic puzzle, since no explanation of the mechanics is necssary. All you have to do is use logic to figure out the relationships between the various people or items being discussed.

But don’t let that fool you into thinking they are easy! That’s where the grid comes into play. Using it, you can make notes on the relationships between each pair of properties, ruling out the impossible until only the possible remains.

Five neighbors, conveniently named Alice, Bob, Carl, Diana, and Eve, live in a row of five houses of different colors, with different pets, and preferring different beverages. Using the clues below, can you determine who is who?

  • Diana lives in the rightmost house, not the blue house.
  • The coffee-drinker lives next to the green house.
  • The owner of the fox prefers water.
  • Carl enjoys tea.
  • The person who likes milk dislikes snails.
  • The fox lives in a yellow house.
  • The ivory house is located to the left of Alice’s house.
  • Diana owns a zebra.
  • The fridge in the rightmost house holds a lot of OJ.
  • Bob lives somewhere to the right of the red house.
  • Carl lives nextdoor to the leftmost house.
  • The dog owner is an immediate neighbor of Diana.
  • Alice lives in a red house.

The grid below links to a nifty web app that you can use to help solve the puzzle. There’s even an option that will help autofill the grid if you’d like some extra help (“Draw Conclusions”), or you can leave it all up to yourself (“No support”).

calcudoku

Sudoku

Are you allowed to write a book of logic puzzles without Sudoku? I’m not sure you can. I certainly didn’t!

In case this is your first experience with this popular puzzle format, the rules are simple: fill in the numbers 1-9 within the grid so that each number appears exactly once in each row, column, and 3x3 subsquare.

Click below to print and enjoy!

sudoku

Masyu

While I’ve worked with all the other puzzle types for a long time, to be honest I’m a very recent Masyu solver! And boy was I missing out – these challenges are a lot of fun!

The task at hand is to draw a single cycle of horizontal and vertical lines that passes through each box that contains a circle. Lines that pass through black circles must do so at a 90° angle, but must pass straight through both adjacent squares. On the other hand, lines must pass straight through white circles, but must turn 90° through one adjacent square (or possibly both). Not every square of the grid must be passed through.

Of course, they say a picture is worth a thousand words. A printable puzzle is available through the picture link below.

masyu

Cryptic Puzzles

My last and favorite puzzle type found in the book is the cryptic puzzle, also known as puzzlehunt-style puzzles. You’ll have to wait for my next update for my teaser cryptic puzzle, but here’s a small clue for now… maybe hold on to your Sudoku and Masyu solutions if you work on the above examples. :-)


Follow me on Twitter at @StevenXClontz for updates! As the book release date approaches, I’ll be doing a couple giveaways, so keep an eye out if you’d like to score a free copy.

Join the conversation by tweeting #TrickyLogicPuzzles: