Spectator's card trick

You can use any deck for this trick. The spectator can shuffle it.

In this trick, you will be the spectator and your spectator will be the magician, so your presentation and performance will be the key to selling this effect.

When you get the deck back, you have to determine which card is the top card. You can either look at it quickly while doing a riffle shuffle, or you can look at the bottom card and control it to the top using an overhand shuffle.

Now ask the spectator to ask you to pick a card and memorize it. Don't show it to anyone, because in reality, the card you will be searching for will be the top card. To make it more convincing, put the card back near the top of the deck.

For fun, you can now ask the spectator to ask you what is your card, obviously they will be wrong. So you can now ask them to ask you for a number between 10 and 20.

They can deal that many cards on the table, and show the card on top of the rest of the deck. This will not be your card, so they can deal it on the table too, and put all of this on top of the deck.

Next, they can repeat the same thing with a bigger number, between 20 and 30.

Now, subtract these 2 numbers together, and deal the corresponding number of cards.

They can finally reveal the card on top of the deck, which is your "selected" card.