## Domino Effect

Two spectators create a chain of "dominoes," using pairs of cards to represent dominoes. Despite almost total freedom in choosing the dominoes, they find that the magician has predicted the beginning and end of the chain in advance.

Remove two pairs of cards that match in both value and color; for example, the red Sevens and black Queens. Take one of each and put them into an envelope to be used as a prediction. Then remove eleven more pairs of cards. These only need to match in value, not color. It's alright to have more than one pair of the same value; e.g., two different pairs of Eight. Just make sure that none of the pairs are Sevens or Queens (in our example).

Assemble the deck with the remaining red Seven and black Queen on top, followed by the eleven pairs of cards, then the remaining twenty-six cards.

### WORKING

1. Begin, saying, "Has everyone here played with dominoes at one time or another? Just to refresh your memory, dominoes are small rectangular tiles, with a different number on each end. Instead of dominoes, we're going to use pairs of cards."

As you talk, give the deck a Jog Shuffle, leaving the top half unchanged.

2. Continue, saying, "I need two people to help me build a chain of card-dominoes. I'll take some pairs of cards off the deck. I have to use pairs since each domino has two numbers. we need enough to make a reasonable chain, but not so many that it will take us forever, so just stop me whenever you like."

As you're talking, deal pairs of cards off the top of the deck onto the table. You should have dropped five or six pairs before you suggest that someone stops you. You don't want to deal more than twelve pairs, so if you get to eleven and still haven't been stopped, pause and say "This is probably enough. Or would you like me to use one more domino." That gives them a choice, but still stops them where you want to stop.

3. Set the remainder of the deck aside, as it won't be used further. Mix the cards on the table in order to destroy the evidence of the pairings. Leave them mixed on the table and have one spectator pull out any two cards to serve as the initial domino. Turn them face-up and place them side-by-side on the table. Let's assume they laid out a Two and a Five.

4. Say, "That's the first domino. When you play dominoes, you create a chain by adding a new domino to either end of the first, one that links to it." Gather up the cards and hand them to the second spectator. "In this case, you need to make up a domino out of two cards: one has to be either a Two or a Five, but the other can be anything you like.

5. The spectators alternate, choosing cards to make dominos, until eventually they can no longer find a card that matches either of the end cards. This will be because those cards are the red Seven and the black Queen that match your predictions. Take the remaining cards, if there are any, and add them to the other discards.

"You've created a unique chain of card-dominos. No one could have known what cards you would select initially, nor what cards you would select to continue the chain. The number of possible chains you could have selected is astronomical. Of the billions and billions of possibilities, you created a chain with these two cards on the ends.

Remove the two end cards and place them in the middle of the table. Pick up the remaining cards from the chain and add these to the discards. Now ask someone to open the prediction envelope and take out the two cards within.

Finally say, "Isn't it amazing then, that I predicted not only the numbers on the end of the chain, but actually matched both the number and the color of the final two cards! That's the Domino Effect."

Note: If at any time, the spectator chooses a pair of cards that match both ends of the chain, casually tell them "Only one end at a time. Pick one of the two and then another card." You need to prevent this as it would end the chain prematurely.

Let's say the spectator removes a Five and a Jack. Show him how to place the Five next to the first Five, then the Jack next to it (Fig.1). Then hand the cards to the other spectator and tell him that his "domino" has to have either a Two or a Jack, plus any other card.