The magician shows an envelope that contains a prediction and asks a spectator to choose a card. He then opens the envelope from which he pulls out a card which he places on the table saying that it is the chosen card. But he is wrong. He repeats it for other three times but he always fails.
At the end he turns upside down the four cards placed on the table and the audience will see a giant card that represents the chosen one.

Amazing and easy to do.
  
The cards are poker size.