Core rule · Rules Tome 2.0.8 § 400
Zones of play
Cards move among formation, action, deck, hand, discard, banish, battlefield, and dungeon areas.
How it works
Full rule
Formation, action, battlefield, and dungeon zones are in play. Deck, hand, discard, and banish zones are not. When a card leaves play, cards attached or equipped to it are discarded or destroyed in the required order.
At the table
Example
A revealed card on top of a deck is still in the deck and is not in play.
Watch for this
Common mistake
A visible card in a discard or banish pile is still not in play.