It's the sort of conundrum that apprentice wizard Merlin - eponymous hero of the current BBC children's drama - needn't concern himself too much about: how do magicians stop others from pinching their tricks?
Mere mortal magicians, however, are less fortunate and often find themselves wrestling with this very down to earth difficulty.
It's a problem that has tested Guy Hollingworth is both his profession (intellectual rights lawyer) and his ardent passion (Hollingworth is a highly regarded magician).
The crux of the problem is this - magic is about dark arts and mystery. Whereas codifying something in law tends to mean setting it down in black and white, for anyone and everyone to pore over should they so desire.
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Hear Guy Hollingworth on Law in Action, BBC Radio 4, broadcast on Tuesday 11 November at 1600 GMT
An idea alone cannot be covered by law, and so simply inviting someone to choose a card, for example, and then making it appear in a wallet, is not something the law can or will protect, says Hollingworth.
A scripted presentation of a trick however, would amount to a "literary work" in which copyright exists and unscrupulous competitors could be sued for breach of it.
But this still does not protect the trick per se - merely the presentation of it.
Some go further and set out to patent their tricks. But in order to do this the trick has to be relatively detailed. The more flesh that is put on the bones of the basic trick, the more chance there is that it can be protected by the law of designs, patents and copyright.
"The kind of magic that has been patented tends to be the species of detailed large scale illusions practised by the likes of David Blaine and David Copperfield," says Hollingworth.
"That's perhaps a hangover from the hey day of the grand illusion where magicians would travel the globe performing stage spectaculars at which it was not unknown for other magicians to attend, watch, and even jump up on stage, run around the back, and see just how the illusion was created."
But patents or registered designs create their own problems. Once a trick is patented it is by definition revealed, and competitors can look at the patent and discern the method.
Guy Hollingworth's magic trick: pick a card
So, seeking to protect a magic trick by law ends up being counter-productive, on the basis that anyone can suddenly find out how it's done.
The one area of law which respects the magician's desire for secrecy is the law of confidence - essentially the methods that are used to protect trade secrets.
However, the bigger problem is this, says Hollingworth: "Can you stop the world as a whole from revealing secrets?"
The answer would seem to be a resounding "no".
"There are many magic conventions around the world where magicians talk shop. Anyone can go to one of these, just as anyone can walk into a magic shop and buy one of the many books that explain magic tricks."
Even the security and secrecy of the many magic clubs, of which the Magic Circle is one of the best known, is porous, he says.
"A lot of magic tricks are available outside magic clubs," says Hollingworth. "Fortunately most people aren't sufficiently motivated to go and find out how they are done. But it is difficult to for a magician to argue that they have maintained a trade secret."
It helps explain why there have been so few legal claims by magicians against those who chose to reveal the method behind their tricks.
The famous case of the "Masked Magician" in the United States, who blew the gaff on a raft of magic methods, failed because it could not be argued that the tricks he divulged had been cloaked in sufficient secrecy before he revealed them.
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