Card
From Castle Wiki
A Card is an interactive scene in Castle. One or more Cards together compose a Deck. Each card may contain some art, sound, logic, and other interactive elements in the form of some Actors in physical space.
Many decks on Castle consist of a single card, containing a simple toy, game, scene, or world. Creators can optionally add more cards to the same deck, for example to introduce multiple different scenes or levels, and then use Rules to send the player between different cards in the deck in response to narrative actions or gameplay achievements.