How to win bets and make enemies with a simple card trick:

First, take 21 playing cards.

Fan out the cards, facing your sucker, and tell them to mentally choose one of the cards.

Shuffle the deck, and start dealing the cards out one at a time, face up, into three piles. Instruct your sucker to watch for their card and remember which of the three piles it lands in.

Ask your sucker which pile the card landed in.

Gather up the cards, one pile at a time. Make sure you place the pile indicated by the sucker in the middle, between the other two piles.

Repeat this process two more times (a total of three times.)

At this point, oddly enough, the sucker's card is the tenth card from the top of the deck. Perhaps someone else can explain why this is so. I only know that it is so.

Now, here's the twist that will win your bet, or get you killed, or get a laugh, depending on how far you're willing to push it.

Deal the cards out one at a time, turning them over. Watch for that tenth card. That is the sucker's card. When you come to it, keep right on going and deal out a few more cards. Then stop, pause with the next card in your hand, and say:

"I bet you (some amount of money, preferably $0.00) that the next card I turn over is your card."

At this point, the sucker has already seen his card go by. He knows the next card can't possibly be his. So naturally, he'll take the bet, it's a lock.

Then, you put the card that's in your hand back on top of the deck, sift through the pile of cards you already dealt, take the sucker's card out and turn it over, face down.

And now is a good time to run for cover.

Of course I have given only one way to locate the sucker's card. There are a million different ways to do that, of course.