One of the most widely used tools for many magicians is a regular deck of playing cards. They become a magic card when the performer begins to use them to play a trick. The simplest trick involves a member of the audience picking a card at random from the deck and then reinserting it. Then the magician does some fancy handwork with the cards and somehow pulls the selected card from the deck.
Tarot and other divination cards can also be considered to be a set of magic card. They are used by fortune tellers, new agers and sorcerers. The cards are arranged into two types, major arcana and minor arcana and are used for foretelling the future. Their divinatory meaning is derived from Jewish Cabbala mysticism and alchemy.
The use of a magic card for divination can be traced back to the middle ages, and was probably practiced for hundreds of years before then based on the complexity of the cards that have been discovered. The cards could also be used in the same way we use playing cards today, for fun and gambling.