A card trick was a type of magic trick involving the manipulation of playing cards.
In 2266, Charlie Evans demonstrated a card trick to Janice Rand that he claimed one of the crew on the Antares showed him; he changed the image on the cards to show her face. He then disposed of one of the cards, only for her to find it in her uniform. In reality, he was using the powers the Thasians imparted him with. (TOS: "Charlie X")