duel disk
A device used for playing Duel Monster card games in the Yu-Gi-Oh! manga and anime. Typically takes the shape of a forearm-mounted contraption with foldable blades that is used to place cards on it. The device utilizes "Solid Vision" technology to generate hologram of monsters and cards played by both players.
In real life, the device was conceived by Takahashi Kazuki as a way to give characters an ability move to more freely during a card game match for dramatic effect instead of having them duelling on a table.