The Monty Hall problem is a famous one in probability. It is based on a TV game from the USA called "Let's make a deal" (1963). It is named after the original host of this show. Inspired by this game, here is an original effect and a great plot for stage, parlour or close up. This unpublished method is easy to do and costs nothing. There is no maths or memorization or difficulty of any sort. It does require some one-time preparation, but just with some index cards, a sheet of paper (for the list of prizes), and a normal pen, nothing else. It can be adapted to your style, venue, weddings, birthday parties, Halloween, Valentine day, corporate events, kids shows etc. The list of booby prizes can also be very easily customized or changed for strolling, and be a good opportunity for comedy Magic!
Three business cards are put on the table, along with a list of random lottery numbers and prizes. Two of the cards have a lottery number written on the back, and the third one has a car. The spectator chooses one of the cards, WITHOUT LOOKING AT IT. The performer looks at the three cards, and turns over one that he knows is a booby prize card of course. The spectator is now invited to either keep his original card, or to swap it against the other
one. Whatever he does, he will always (100%) lose.
(Note: You can also make the spectator win all the time, if you prefer. The performer can also predict whether the spectator would switch or not.)
1st edition 2015, 37 pages.
word count: 3229 which is equivalent to 12 standard pages of text