Hidden spike trick explained (+Tutorial for a safe method)

The “Hidden Spike Trick”, sometimes called “Nail under bag” as well, is a very dangerous magic act. The magician puts one nail pointing upwards underneath several cups or bags and tries to smash them one by one with his hand until there’s only the last one left – the one with the nail underneath.

How the spike cup trick is usually performed:

The magician puts a nail underneath multiple cups or bags, turns around, and they are mixed up by a spectator. Now, he smashes them with his hand one by one until there is only one left. If something goes wrong, his hand will be damaged.

There are different ways to perform this trick, I’ll explain three methods in this post. Down below, I’ve included a safe alternative as well, that you can perform yourself if you like the trick.

Let’s get started.

Technique explained: How magicians can find the nail under the cups

First, I’ll explain how this trick works when performed by professional magicians.

However, please keep in mind that this magic trick doesn’t work every time and people have even gotten hurt performing it on TV. So never do it with a real nail!

Also, I would like to clarify one thing right at the beginning:

The magician never relies on his “intuition” or tries to interpret the spectator’s reaction. The cups are marked.

The cups are either marked (there are several ways to do this) or the magician uses a special gimmick that allows him to find the correct cup.

Smash and stab magic trick revealed (three different versions)

No magician in the world would risk his health for such a trick.

That’s why the cups are marked, and the magician simply remembers the cup under which the nail is located.

The only problem is that the spectators must not notice this. The markings must be so inconspicuous that they are almost impossible to spot for the audience.

I’ll explain a few techniques that are used pretty commonly.

Method 1: The serial number of the cups

Some plastic cups have a serial number stamped on the bottom of the cups, which can only be detected when looking closely. This allows the magician to distinguish the cups and he simply memorizes the serial number of the cup with the nail.

This way he can find the correct cup again, even if a spectator has mixed them up before.

I’ve explained this method down below in detail, it’s pretty easy to master and you can use it to perform a trick yourself (without a nail, obviously!).

Method 2: Marking the cups in a different way (e.g. with thin threads)

Another option is to mark the cups with other objects. An example is three threads of different lengths that are attached to the cups. This also allows the magician to distinguish the cups and keep them apart.

However, this variation is very risky and could be noticed by the audience. For example, if a string falls off, the trick has to be canceled – otherwise, the magician could actually hurt his hand.

Method 3: Using a special gimmick

Another variation is to use a special gimmick. I don’t want to give away any well-kept secrets of magic here, but there are definitely other methods to find the nail under the cup.

Still, there is always some risk involved when performing the trick with a real nail.

Never try this trick at home with a real nail!

I’ll show you an alternative that is (almost) as exciting, but you can’t hurt yourself.

A safe alternative of the trick that you can perform yourself

If you want to copy the magic trick, just use another object (for example, a piece of paper) instead of the nail. Of course, the trick will not be as exciting and dangerous, but it will be just as impressive.

You can also sell this effect as a “mental magic trick” because you supposedly “read” the spectator and can see read his mind.

What you need for this:

  • Three or four plastic cups (with different serial numbers on the bottom of the cups!).
  • A small piece of paper (or something similar)

The only important thing is that you can tell them all apart (hence the numbers on the bottom of the cups have to differ). You may have to search a bit to find such cups.

Quick tip
These cups not special "magic cups", but ordinary cups that you can buy in almost any supermarket.

Next, you need a small object that the spectator can put under a cup. You can use a piece of paper for this, but of course, you can also use dice, a coin, etc.

Tip: It’s possible that you can see a dark object from the outside through the cup wall. So you are on the safe side if you just use a white piece of paper (otherwise the spectators might accuse you of being able to see it through the cup wall after the trick).

In both of the explained variations, I use a small piece of white paper that is placed under the mug.

Safe version 1: Serial numbers

There are two different variations on how you can perform this mug trick.

For the first method, you can use as many cups as you want (I would recommend three or four). You turn all the cups over and ask a volunteer to pick a cup.

You then place the piece of paper under that cup and remember the serial number on the bottom of the cup. Make sure to use cups that have different serial numbers at the bottom!

When turning around, ask the spectator to switch all the cups as many times as they want. As soon as you turn back around, all you have to do is find the cup with your memorized number and you will immediately know where the piece of paper is.

Safe version 2: Keeping track of the cups

With this method, you have to use exactly three cups, and one of them must be different from the other two.

Place the three cups upside down in front of you on the table and give the small piece of paper to the spectator. You turn around and the volunteer may put the piece of paper under a cup of his choice, swapping the other two cups.

You memorize the number of the middle cup before you turn around. This will allow you to tell where the piece of paper is afterward.

So, here’s how the trick works:

  • You put three cups upside down in front of you on the table.
  • Remember the number of the cup in the middle.
  • Turn around and ask the spectator to put the piece of paper under a cup of his choice.
  • Now he should swap the other two cups (the cup with the piece of paper does not change its position!).

Then, to find the piece of paper, you just have to check where the cup is whose number you remembered (I’ll call this cup “your cup”). There are three possibilities:

Position of “your cup”Position of the piece of paper
Your cup is still in the middleThe paper is under the middle cup
Your cup is on the leftThe paper is under the right cup
Your cup is on the right rightThe paper is under the left cup

I’ve explained each possibility once, if you are interested, you can read it through. But it is enough if you just remember the table above.

Possibility 1: Your cup is still in the middle.
This means that the spectator has placed the piece of paper under the cup in the center. He should swap the other two (empty) cups, but since your remembered cup is still in the middle, the piece of paper is there.

Possibility 2: Your cup is now no longer in the middle, but on the outer left.
This means that the spectator has placed the piece of paper under the cup on the right. If the cup is moved in the middle, another cup must be. So if your remembered cup is now on the left, it was swapped with the left cup – and the paper is under the right cup.

Possibility 3: Your cup is now no longer in the center but on the far right.
This means that the spectator has put the piece of paper under the leftmost cup. (Explanation exactly as for possibility 2, only the other way around).

A few tips for the performance of the magic trick with spikes under cups

With the two variations explained, it’s relatively easy to find the spectator’s piece of paper. You turn around, the spectator mixes up the cups and when you turn back again, after a few seconds you know where the paper is.

Quick tip
Always take your time when performing this trick, the audience will get suspicious otherwise.

So here’s how I would do it:

Distract your audience with completely irrelevant questions that have nothing to do with the trick. That way, the focus is no longer on the cups themselves, but more on your “ability to see through people.”

A short example:

The spectator chooses a cup and you turn around for a minute. When facing the audience again wait a few seconds. Then you look deeply into the eyes of the volunteer in front of you and tell them that you already have a premonition.

Now ask the audience member what his/her favorite color is (or whatever else comes to mind). Then ask him/her if he/she is right- or left-handed (as I said, this has nothing more to do with the trick – pure distraction).

You can turn this trick into a “mind-reading” illusion, by asking the spectator a few random questions to make it look like you can read his thoughts.

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