How do they do magic tricks involving random audience members?

I was just at a David Copperfield show tonight, and most of his tricks involved the use of seemingly randomly chosen audience members. He would drag people up on stage and have them write down a number, card, secret, etc. He would then show that he predicted everything they wrote down or overwise conjured up for proof. Now, the only explanation for these tricks is that he uses audience plants. Either that or he’s actually magical.

What I’m wondering is, how does he pull off the illusion that his audience picks are truly random? His schtick was he’d toss an object into the crowd, and when someone grabbed it they would show that person on a large tv screen, holding the object. The lucky fella would then go up on stage to participate. I would imagine that he purposely throws the object to a section of the audience filled with people that were in on the act. Sometimes you could clearly see it being passed along by several people before it got to the right person. But what happens if he misses or fumbles the shot? What happens if someone else jumps up and grabs the ball/frisbee/whatever before it got to the target area? If that happened, the entire act would be shot. How’s it done?

I’m afraid your basic assumptions are incorrect. I am not a magician myself, but I have seen many magic shows. I cannot tell you exactly how these tricks are done because I do not know the specifics of these particular tricks, but the amazement proceeds from the fact that most of the audience thinks the way you do.

I’m sure several posters will pop up in this thread explaining why no one should tell you how these tricks are done, but there are many books written on the subject, easily available to anyone interested enough to look for them or to buy them, that will explain some ways of performing these mentalist acts.

I’ll give you a bit of “proof” that I am correct. What cemented this concept for me as a young kid was seeing a particular trick done once or twice. The magician would throw a pretend pack of cards into the audience, then ask whoever “caught” it to throw it to someone else. He would then ask that second (or third) person to “open” the pretend deck of cards, then have a person next to him “pick” one of the pretend cards. When he asked that person what card he had picked, surprise! He “magically” produced some flamboyant way of demonstrating that he had that card written down already.

Since I’ve seen this trick done at a private party where I personally knew several of the people who ended up participating, I knew it wasn’t based on a plant who called out the card he had already written down. It couldn’t have been any tricky way of detecting or seeing the card that was picked, because there wasn’t really a card! I dismissed the possibility that real magic was involved (this was before I ever saw Willow do her stuff on Buffy the Vampire Slayer).

The logical conclusion to me that all the flamboyant invisible card theatrics aside, what the magician really accomplished was somehow being able to produce in short order in some flamboyant way ANY GIVEN CARD at a minute’s notice. That was the trick.

If you think of it in those terms, I’m sure you will also agree that whatever trick it was that mystified you, the way David Copperfield did it was not limited to either having a confederate in the crowd or using real magic.

There are many ways to achieve a trick like that, including using elaborate props or set pieces to drag the trick out for a long time, giving the chance for other machinations to occur behind-the-scenes to achieve the result.

But the simplest way, and I use that term advisedly, is to engineer the trick so that every element may appear random, when in fact most of them are not.

There’s also the famous mind-reading trick, where audience members write something on a piece of paper, seal it in an envelope, and write their name on the outside of the envelope. Envelopes are all put in a bowl. The magician draws an envelope from the bowl, calls out the name and tells the person what’s in the envelope; opens it to confirm, and repeats this many, many times.

Of course, the first person called on is a plant. Then the magician is one step ahead – he pulls a second envelope, but calls the name of the person that was really on the first envelope (if you follow me), which he’s already opened. He pulls a third envelope, but calls the name of the person on the second envelope.

Most of magic involves preparation, hidden gimmicks, and misdirection. The specifics vary with each trick – if you see the same trick often enough, you can usually see through the misdirection.

Not true. There are other explanations. That’s how magicians, such as myself, make a living. Obviously, we don’t discuss our methods on a public forum such as this. However, I am pleased that the illusion of magic was so strong and compelling for you. Copperfield’s show is one of the greatest magic shows ever put together.

It’s no illusion. His audience picks really are random.

If you want to know how the tricks are done, take up an interest in magic and mentalism (mind-reading magic) and pursue it diligently for many years. You’ll get there in the end!

I have done a little amateur conjuring, I’m not going to tell you the full details, but here’s a few hints.
First of all, there is The Force - yes, its really called that. Magician can trick the volunteer into thinking he has a free selection, but actually he picks the item magician wants him to.

Then there are various methods where the volunteer is genuinely given a free choice, the magician gets a sneak peek at the choice, then reveals it to the audience. One example is using marked cards, but there are much cleverer methods than that

Then there’s The Boon - the magician has a cunnigly concealed pencil in his hands, and writes down his prediction after the volunteer has revealed his choice

Then there’s the Get Out - no matter what card is chosen, the magician has a way of revealing that he ‘knew’ that. “Aha, you chose the ace - observe as I remove my glove, see that the word ‘Ace’ is written on my palm. Thank you” " Aha you chose the seven - observe as I raise my foot - see how the word “seven” is printed on the underside of my boot. Thank you"

And loads of other methods too.

What happened to the admonition some time ago by the SDMB admins, that we could be banned for revealing the way professional magic tricks are done. Is that still an SMDB policy?

That was an intellectual property issue, which I believe was resolved. It was decided, IIRC, that revealing the essence of a a trick in one’s own words was acceptable, and did not violate any US intellectual property laws.

Ok, so my source is the NBC show “Las Vegas,” but the technique portrayed certainly makes sense. In those shows where the magician/mentalist “reads” the minds of members of the audience, hidden microphones have been placed in various spots and monitored while the audience waits for the show to start.

Then there’s the probability play. This involves asking someone to name one or two things and have the magician show he’s predicted this. It turns out there are some questions that will seem to have an endless number of answers, but where one or two will be chosen by people often enough that magicians can perform mind reading tricks with them. Here are two:

Select one of the following numbers:

1 2 3 4

Only Dopers pick 3

Pick a random number between 10 and 40, both digits must be odd, and the two digits cannot be the same as each other.

You picked 35, or was it 37

There are many of these. Dig around in the magic section of your public library and you’ll find more.

Since Carnick’s “basic assumptions” are clearly “incorrect” according to nearly everyone here, perhaps someone can tell me how David Copperfield manages to pull off the following favorite act of his, which has had many thematic variations over the years, each one getting a bit harder to pull off but nonetheless all working on the same principle. (Please also note that despite what I have to say may seem more like seething skepticism than the typical SDMB “fortuitous agreement response”, that I hugely admire Copperfield and acknowledge his amazing skills, and that I am only posting this because I am not only a very scrutinous fan, but also someone who draws a line between what is logically feasible and what is not.)

He pulls a person from the audience (randomly, of course!) and sits them down to talk, all the while having a covered blackboard off to the side of the stage, in full view of the audience. He tells the audience that he’s written something down on the board, which he’ll reveal by the end of the trick. No one can see what’s written on this board, of course, as it’s covered with a fancy drapery. Only after talking to this “totally random audience member” about whatever topic it is he or they choose to speak on, he reveals what’s on the board: essentially a perfect transcript of the details of their conversation is read aloud while we watch in amazement! We’re supposed to wonder at how he could have possibly known all of that beforehand, and how if he didn’t have precognitive psychic powers, it could have possibly been written on the board after the fact, since we’ve seen it standing there on stage completely untouched and in full view. We’re supposed to ask ourselves how it could be possible since the totally random audience member is a totally random audience member.

The fact is, the audience member isn’t totally random, it doesn’t really matter which of them does most of the talking, what the subject was, or how the audience member appears to have been selected, because the audience member is a plant. Years ago, Copperfield would scarcely hesitate to go out and hand-pick an audience member himself (at least, he did on several of his numerous ABC television specials). Whether or not he still does this in his current performances is irrelevant, because I wouldn’t be surprised if he’s ditched the hand-picked audience member method in favor of the more believable “random toss” selection in recent years. More than likely, he still uses both approaches, but his method for getting the plant to the stage in a seemingly random manner is the real trick. The material itself is scripted, memorized, rehearsed and written on the blackboard beforehand, of course, and then performed with an extemporaneous and witty conversational exchange onstage so as to make the audience believe the plant is real. Copperfield’s ability to make viewers believe he has a random and impartial audience member is the lynchpin to making the trick work, and this is why the repartee between the two of them must be very fluid and believable. As Peter Morris here offered, this is the “Force” technique at its very best, but instead of forcing the random participant, he’s forcing the audience (with a disarmingly cute performance) into accepting the illusion that the participant is randomly chosen.

Copperfield has also done one rather impressive variation on this illusion with audience members who use spraycans to paint cute little pictures on a big piece of white linen. After they’re all done spraypainting their doodles, Copperfield removes another sheet from an envelope that has been hanging in view of everyone the entire time, and to our amazement, the drawings are virtually identical to the ones the audience members made. Same concept, more impressive performance. I wondered endlessly about how this could have been even remotely possible, and the fact is that it isn’t. It’s rehearsed and the supposedly random participants are more than likely well-practiced members of Copperfield’s payroll. Perhaps this is where those aspiring amateur actors who don’t get chosen on their final audition for the latest TV reality show go to get work?

I beseech anyone to prove me wrong, and will gladly accept the “magician’s code of secrecy” pretext as proof that I’m right. Perhaps as a disclaimer, I should state that this post reflects only my own opinions, that I’m not a magician, and that these are not official secrets so that I’m not in danger of being blackmailed, kidnapped, or tortured by the secret society of aspiring stage illusionists.

anamnesis, perhaps the trick you describe can be reduced to the standard “one thing magically replaced with another” trick, where the chalkboard on stage is replaced with one off stage with an assistant transcribing the conversation, much like a lady being replaced with a tiger.

I don’t know how other replacement tricks are done, but perhaps some of those techniques can be used with the chalkboard, and hence still have a truly randomly picked audience member.

Just speculating, I have no real knowledge of these are done.

Damn it. I fell right in with 3 and 37. But why 37? I thought that I deliberately picked something that most other people wouldn’t pick.

With magic, you must remember that nothing is what it seems to be.

With the technilogical advances we have today, in contrast to what Houdini had available, it’s a wonder that magicians can still mystify folks. (Think about it. . .I’m in my study typing this and you halfway around the world are reading it seconds later. . .that’s MAGIC!) The biggest tricks magicians pull off are making you think you’re seeing one thing, when in fact you’re not. There are many, many ways to “write” a message on a covered “blackboard” that have nothing to do with a hand holding a piece of chalk. But the audience doesn’t even consider that possibility. As long as the audience thinks it’s seeing an ordinary slate chalkboard (Do they even make those today?) and that it’s not switched or not written on during the act, the trick works. The audience member is probably not a plant. The magician did not know what the person was going to say and did not write it on the board in advance. The trick is how to get the words on the board while its covered with a cloth.

If the audience member really was a plant, why aren’t there hundreds of ex-audience members singing like canaries as to how it was done.

I picked 31.

I would think that an easier way to “randomly” pick a plant would be to not really throw the item, and then have the plant hold up an identical item that he/she already had.

I had a “magic trick” book when I was a kid that explained several more commonly used schemes, but the only one I remember is the Forced Choice.

I also remember reading at least one novel in which a supposed “genius” type figured out the magician’s mindreading schtick and demonstrated how it was done. It’s obvious once you know how it’s being done. :wink:

[QUOTE=Julius Henry]
Then there’s the probability play.QUOTE]

I bombed both of 'em with a 1 and a 13.

I guess I’m not a magically inclined sort.

Remember that picking 35 or 37 is merely playing the odds, not saying that everyone will pick those numbers.

The same kind of trick is used by mediums and ESP-type tricksters, See Straight Dope Staff Report: How come TV psychics seem so convincing?, to which our own ianzin gave invaluable information.

If you’re interested in cold reading and similar magicians’ tricks, I recommend The Full Facts book of Cold Reading, written by ian, and available from his website at (Note: we normally don’t allow such “advertising”, but Ian’s stuff is a Moderator-approved exception.)

Similarly to the above, I have demonstrated ‘ESP’ at my School.
I asked a pupil to think of a number between 1 + 10. Then I told him he was thinking of 7 (reasonably likely). I followed up with ‘think of a colour’ = ‘blue’.
Gratifyingly, his mouth fell open! :cool:

I’ve had the pleasure of being on Derren Brown’s TV show. Not only is he an impressive illusionist, but also a very polite chap!

Another example of Thr Force that I’ve seen is getting someone to take one of two items. For example the magician holds up two books (A and B). The magician wants the volunteer to take book A. They hold up both books and announce “Please point at the book you feel is more magical.” If the volunteer points at book B the magician will then say “You chose book B to be more magical so that is the book I will use to perform magic, you hold on to book A.”
If the volunteer points at book A the magician will say “You chose book A to be more magical, therefore I will give you book A.”
Either way it appears that the volunteer had control over the choice (which he did) but it was never said what the choice would result in.