This is a very cool easy magic trick that anyone can do, and depending on how good you are, you can add or take off the sleight of hand at the end of the trick.
The first step is to separate out 15 cards from a normal deck of cards. These can be any cards accept the jokers, even the jokers if you really wanted.
Hold up the 15 cards to the person you are performing the trick for. Ask them to memorize a card that you are holding. They don't have to touch the card or take it out or anything, they just havwe to remember any of the cards.
Next, lay the cards down on the table in three rows of five. Then pick up each row of five, and ask the person if their card is in that pile. When they say their card is in that pile, put that pile on top of the deck of 15 cards. You now know that their card is one of the top 5 cards.
The next step is to lay the cards out in three rows again, but this time you have to lay out the cards so that the first row has 2 cards out of the five at the top, the next row has two more, and the last row has 1. This makes it so that if the person says their card is in the first row, you know it is one of the top two cards in that row, if they say it is in the second row, then you know it is one of the top two cards in that row, and if they say it's in the third row, you know their card is the top one in that row.
If their card is in the first two rows, you will have to repeat the last step once more, where you put one of the possibles at the top of the first row, and the other possible at the top of the second row. If their card was in the last row, then you know their card is the top card in that row, and can go to the next step without putting out rows again.
Now that you know which card is theirs, you have to present it to them in a cool way. If you really want to at this point, you can just flip the card over and say, "Is this your card?", but that's not a very good performance.
The first part of the big reveal, is to get the audience involved. Give them a choice so that they feel they've affected the outcome, when they really haven't. At this point you have the stack of 15 cards, where you know which card belongs to the person. I usually put it as the sixth card in the deck, but putting the last pile that they said their card is in between the other two piles. I then lay the cards out to look kind of like a person, where there is a card in the center, and then a corner of each of the other four cards touching a corner of the card in the center. Make sure to remember which card is theirs while putting them down, so that you remember when you pick them back up.
Then give the person a choice. Tell them to choose two piles. If they choose the pile that their card is in along with another, get rid of the third pile. If they choose the two piles without their card, get rid of those two piles. This will make the person feel even more amazed by your trick, because they think they have affected it.
After this, put their card in the center of the cards that are left. Make sure to practice this part, so that you can do it without them noticing. It's good strategy to distract them with talking or pointing at the pile that you threw away while doing this. Make sure to leave their card sticking out a bit, so that you can clamp it with you pointer finger and middle finger more firmly than the other cards for the next step.
For the big reveal, hold their card tight while holding the other cards more loosely, the KARATE CHOP the pile. Do it in as extreme a way as you can, really surprise them if possible. With your karate chop make sure to be holding their card very tightly so the other cards fly out of your hand but that one remains.
At this point, flip their card over and ask, "Is this your card?"
If someone asks, "How did you do that?" DO NOT show them. It will ruin the trick and will leave you with less people to perform for. Magic is a lot more fun when it's mysterious, so it's better for both of you to keep it a secret. They can research it on their own if they're really interested.
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