Making the spectator pick the card YOU want,
while they think they’re picking the card THEY want.

Many times in a magic trick, you will need to make a spectator choose a specific card without realizing that they're picking the card you want them to pick.

Before starting the magic trick, secretly remember the top card of the deck. This is the “force card” that you will force your friend (the spectator) to choose, although s/he will think it is a "Pick a card, any card" kind of free choice.

Have the spectator lift up half the deck, and place it on the table. This is called cutting the deck. You now have two piles of cards, A and B. The card your friend will choose, the force card, is on the top of pile A. Keep track of where the force card is, and don’t forget it.

Tell the spectator you will mark where the cut was. Pick up pile B, and place it sideways on top of pile A. The pictures show how this is done.

Ask the spectator if s/he has seen the card yet, and when s/he says no, lift pile B, and have the spectator take the top card of pile A. Your friend will think this is where s/he cut the deck of cards, so when the card is picked up, they will think it is their card.

Now that the spectator has "chosen" your card, you can go on with whatever magic trick you had planned.

A simple magic effect would be to pretend to concentrate for a moment and then name the force card! Only a magician could know the value of a card without looking at it, and now you can too!