Oracle cards are divinatory card decks that, unlike the tarot, follow no fixed structure. A tarot deck has a set architecture, seventy-eight cards, four suits, a numbered sequence of trumps, that a reader learns once and carries from deck to deck, so that any tarot deck is legible to anyone who knows the system. An oracle deck has no such shared skeleton: each deck is a self-contained creation, with its own number of cards, its own images and themes (angels, animals, goddesses, affirmations, moon phases, or anything else), and its own accompanying guidebook supplying the meanings the deck's creator intends. This makes oracle cards both more flexible and less standardized than tarot: the reader interprets chiefly through the images, the printed keywords, and intuition, rather than through a memorized structural system, and moving to a new oracle deck means learning a new set of meanings from scratch.
Precursors go back at least to the nineteenth century, the Lenormand cards being an important and somewhat more structured early example of a non-tarot divinatory deck, but the great proliferation of themed oracle decks belongs to the modern New Age and self-help market. As a practice, oracle-card reading is used less for detailed prediction than for reflection, guidance, and prompting insight, and it sits within the broad contemporary landscape of intuitive and self-directed spiritual tools.