Tricky Prezzie Puzzle




Introduction: Tricky Prezzie Puzzle

Think back to your last birthday. Can you remember what everyone got you? Sure, perhaps you can remember what gifts you recieved from your nearest and dearest, but can you recall all of the prezzies you got? I know I can't.

That's fine - until you consider that your friends probably can't remember what you got them for their birthdays either. Tsk! After all that time and effort you expended picking them something fabulous! Bloody ingrates.

Well, one way to ensure that your gift sticks in their memory is to make even the act of giving the present into an event. Rather than just handing over a paper-wrapped package, why not present your buddy with tricky birthday puzzle that will ask them to prove their powers of observation and manual dexterity if they ever want to get their hands on the goods? That's what I did for my friend Simon's birthday last year, and it worked brilliantly!

In this Instructable I'll take you through the workings of the tricky prezzie puzzle I set for him, so that you too can frustrate your friends with deviousness before delighting them with nice things that you think they'll like. With a few specialist supplies you can make handing over their gift into a present itself.

Unfortunately, I did this almost a year ago, so I don't have any photos of it. I've used diagrams where possible, so that'll have to do - at least until someone posts an Instructable on how to build a time machine so I can go back and take some snaps.

Spoiler Warning!

This 'Ible contains an explanation on how a piece of simple magic equipment works. If you don't want to have the inner workings of the Magic Bill Box ruined for you, don't read on. You have been warned!

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Step 1: A Little History

My buddy Simon is a fan of the Monkey Island games, so for his birthday I tracked down a copy of the one game in the series he didn't own, The Curse of Monkey Island. I also bought him a neat t-shirt from Cafepress (pictured below). Finally, to top off the package, I bought him a skull-and-crossbones pin badge.

I knew that I didn't just want to hand over the gifts, so I took a little time to think about something cool I could do to make the pressie-giving itself into an event. Inspired by the pirate theme of the prezzies, I started thinking about hidden booty, which in turn led me to think about tricks and traps. Before long an appropriate problem was forming in my mind...

Step 2: What I Used

In order to set up the Tricky Prezzie Puzzle I used the following items:

A magic bill box -
A sheet of flash paper -
Two exploding pens -
Exploding caps -
A sturdy box file
An appropriate length of chain
A combination lock

There are alternatives for the last three items, but the important thing is that you have a lock that requires a combination rather than a key to open it.

Step 3: The Basic Setup

I placed the presents within the sturdy box file, wrapped it securely with the chain and locked the whole thing up with the combination lock. To get at his gifts, my friend would need the combination.

I had written the combination on a piece of flash paper, which was held in the mechanisms from the two exploding pens. These were armed with the exploding caps, and this whole mess housed inside the magic box. In order to get the combination, Simon would have to first work out how to open the magic box, and then figure out a way to remove the flash paper without setting off the exploding mechanisms. Easier said than done, believe me.

Step 4: A Little More Detail

Lets take a more in-depth look at some of the components used in the puzzle.

Flash paper is used by stage magicians for fire effects. It is a chemically treated paper which is about the same strength as tissue. Its name comes from the fact that it ignites extremely easily, and then burns very quickly, leaving behind almost no residue.

Exploding pens are a practical joke. While on the outside they may look like pens, inside they contain a spring loaded mechanism which is attached to the main body of the pen by a hook and which fits into the cap of the pen. To arm the mechanism, the spring-loaded hammer is pulled back and an exploding cap placed onto the firing pin. The hinged flap is the folded back down over the pulled-back hammer, and the device slotted into the lid of the pen. When the lid is removed the hammer is free to spring back into place, firing the cap and creating a loud bang.

The magic bill box is a simple magic toy. You borrow a bank note from a volunteer and place it into the box through the slot in the top. The challenge is to remove the bill from the box without breaking it. Even upon some thorough inspection it appears to be impossible to open the box, but of course there is a simple secret to opening it which I will detail below, just past the spoiler warnings.

Spoiler Warning! Magic Bill Box Explanation Below!

The bill box contains a secret drawer that will not open unless pressure is applied to the correct places. Once the correct pressure has been applied, the draw slides out very easilly.

End Of Spoiler

So, let's recap. The combination for the lock is written on the flash paper. The flash paper is held between two armed mechanisms from the exploding pens, and then everything is placed within the magic box. Even if the victim figures out how to open the magic box, they must do so without allowing the armed mechanisms to go off - if they fire, the exploding caps are enough to ignite the flash paper and ensure that the combination is destroyed.

Step 5: The Tricky Bit

Setting up the exploding mechanism proved quite tricky, so here are some tips which will hopefully make the process as simple as possible.

Firstly, the flash paper. You only need a little bit - having too much makes attaching it to the firing mechanisms more difficult and increases the likelihood that the cap will fail to ignite it. Write the combination as small as you can, and then use scissors to trim off as much excess flash paper as possible. Also, write the combination in pencil rather than pen - the flash paper is slightly translucent and ink marks from a pen would be visible though it, so a devious victim might attempt to solve the combination by reading it through the flash paper.

When placing the flash paper into the firing mechanisms, make sure that you place it directly onto the pin and then put the exploding cap over the paper; otherwise the paper will not ignite. This is another reason to use as small a piece of paper as possible.

Arming the mechanisms was fiddly as hell. I set up the paper and the caps as described above, then placed them all together into the bill box's secret drawer. The bill box is deeper than the armed mechanisms are tall, so you'll need to place something on top of the mechanisms otherwise they'll fire prematurely. Thankfully the skull-and-crossbones badge I'd bought as part of the gift came attached to a piece of card, so I used that.

So, the two unarmed mechanisms and the flash paper were placed into the secret drawer, and then exploding caps were placed onto the firing pins on top of the flash paper. At that point I armed the first mechanism, pulling back the hammer and folding the hinged arm down to cover it. I then armed the second mechanism, using my little finger to hold down the hinged flap of the first and prevent it from firing. When both mechanisms were armed I placed the badge into the drawer on top of them, still holding it down to prevent firing, before sliding the drawer shut.

With the drawer shut the badge was held in place, preventing the pins from firing, but I know from experimentation that if the drawer were opened the mechanisms would have fired. You'll have to do a bit of experimentation yourself to find something suitable to hold the mechanisms down.

Step 6: The Results

The Tricky Prezzie Puzzle was largely a success. My victim had one heck of a time trying to work out how to open the magic box - he eventually did it quite by accident. Once he'd got the drawer slightly open he was able to use a combination of manual dexterity and keen spatial awareness to disarm the exploding trap and discover the combination for the lock.

Writing this 'Ible I've been thinking about improvements that cold have been made, but I'll keep them to myself for now. Perhaps you've come up with some ideas too? Even if you don't follow these plans exactly, or even slightly, hopefully you'll feel inspired to come up with something equally devious for your own friends. Have fun!

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    6 years ago