Effect: A magician takes a plate with 3 envolopes on it. He mixes the envolopes up and the spectator chooses 2 of them. The spectator takes out what is inside of the envolopes and finds just blank paper. The magician takes out what in his envolope and finds a dollar bill.
Secret: First put a blank piece of paper in 3 envolopes and put the envolopes on a plate flap down. Take a folded dollar bill and put it on the table and put the plate on top of the bill. Make sure the dollar bill is in a place so that you can pick up the plate and the bill at the same time easily.
Explain that in two of these envolopes you have put blank pieces of paper and in the other one you put a dollar bill(even though you know thats not what you did). Next have a spectator choose two of the three envolopes. It doesn't matter which ones the spectator chooses they will still have blank paper in them. Move the envolope that the spectator didn't choose to the side of the plate closed to you.
Pick up the plate and the bill. Slide the envolope of the plate along with the bill so your holding the envolope with the bill hidden behind it. Have the spectator look at what is in their envolopes. They will find blank pieces of paper. You need to open the flap of your envolope and insert your index and middle finger but don't take out the paper. Pretent to be taking something out of the envolope, but when you take your fingers out use your thumb to slide the bill up to the top and show everyone the bill.
From the front it looks like you took the bill out of the envolope. Explain that you influenced their actions and had them choose the envolopes with the blank pieces of paper.