If you've never heard of Sudoku, you're not living under a rock in a classy enough part of town. This horribly addictive number puzzle has captured the attention of old and young alike. I was working a puzzle on my Palm while waiting my turn to get a haircut a few weeks ago and an elderly lady next to me told me about the aggravating grid she had worked that morning. Upon seeing my Palm she commented that she might need to buy one of those just to play the game on.

Sudoku is a number puzzle that involves no math and a lot of logic (eh, it's a fair trade off). It's played on a 9x9 grid in which each number from 1-9 can appear only once in each line (horizontal and vertical) and only once in each 3x3 square. It will only take a few minutes to get the concept in your head but many many hours to get the game off your mind. The game is either simplified or complicated by the cells that are filled in for you when you start. The more numbers they give you the fewer leaps of logic you have to take to arrive at a completed puzzle. Got it?

Sudoku (actually "Su Doku." Loosely translated it's Japanese for "solitary numbers") naturally lends itself to puzzle caches. By assigning letters to the horizontal grid (A-I) and numbers to the vertical (1-9) you can direct cachers to individual cells within the grid (as in the image to the right).

So how do you put one together? You have a couple options. One, you can find a pre-made Sudoku puzzle and direct people to the squares of your choice (keep in mind, if there's a zero in your coordinates you'll need to give that one to them). Or you can go to Sudoku-XLS and download a Microsoft Excel document that helps you create your own puzzles.

Of course, it's up to you to decide how easy or difficult you want your puzzle to be. Many Sudoku sites rate their puzzles as either Easy, Medium, Hard, or Insane. It all depends on how many pre-filled squares you provide for the players.

A couple things to keep in mind about this style of hide:

• With nearly 400 different Sudoku-based puzzles hidden at the time of this writing, it's going to take some imagination to keep this style fresh.
• There are many Sudoku solving programs available out there. Chances are some of your finders will use these rather than solving the puzzle themselves. If you're ok with that, then no problem, but you might want to find some way to work around this problem.

Examples

They say that a picture is worth a thousand words, and a well-done picture puzzle cache can certainly generate a lot of words. Some of them aren't the kind we use here though!

A good picture puzzle not only challenges the finder to get to the coordinates but to get inside the hider's head to find exactly what you want them to look for. I've seen some great puzzle caches built around either a single picture or multiple pictures on the cache page.

One common method for this style of puzzle is to provide a set of pictures that correspond to the numbers in the cache's coordinates. One puzzle I've seen had a series of Presidential portraits. To find the cache you had to identify which President was which (difficult to do with some of our lesser-known Presidents) and then identify his place in the sequence of office (example: Washington = 1, Lincoln = 16, etc.). The number in his sequence corresponded to the coordinates needed to find the cache.

The great thing about a puzzle like this is it can be applied to a wide variety of topics to keep the challenge fresh. Instead of using Presidents, try state flags (corresponding with their entry into the Union). Another example I've seen used book covers from a numbered series. The possibilities are practically limitless with this kind of puzzle.

For a different kind of picture puzzle, try a "Magic-Eyes style" 3D picture creator like the ones found here. It will take some practice to come up with one that works well, but it will be worth it!

Examples

Presidents Day
Stereogram
UPC - Unique Puzzle Cache

Remember back when home computers first really took off and suddenly there were hundreds of fonts available with which to express yourself? Remember those friends of yours who would send you their "family newsletter" and assign a different font for each article? Do you remember how annoying that was to read?

Well, who better to annoy now than your fellow cachers? There are thousands of fonts out there for the taking. Many of them fall into the "Dingbats" category, using images rather than recognizable letters. These can be used to create some puzzling codes for your coordinates.

For example, the font used below is called Wingdings and is included with most Windows-based PC's. The coordinates provided, when switched to Wingdings look like this:

With the incredible number of fonts available the ideas for this style of puzzle are practically endless. You can use:

• Dingbats: A specific class of font that uses pictures instead of letters.
• Braille: Braille fonts and even Morse code fonts are both available from a variety of sources.
• Klingon: This is a real fun one for the geeks out there. There are lots of fonts available that build off of languages made up for various science fiction series and movies.

Keep in mind, not everyone has the same fonts installed on their computers. In order for this puzzle to work, you'll need to do a screen capture of your text and paste it as an image file into your cache page.

FontFile - The most extensive collection of dingbats and fonts on the Internet.

Examples

Dingbat
First City Want Ads
Hubcap IV