The Color Changing Card Trick
This card trick from Richard Wiseman is probably best introduced with very little information. Talking too much about it before you watch it might give some hints about what to expect. After the card trick is performed, the video then goes on to show exactly how it was done. Were you paying attention?
If you like card tricks, you may also want to review the rules for various card games. It’s easy to forget how to play some of them which makes a refresher even more important.