108.1 Use the Oracle™ card reference when determining a card’s wording. A card’s Oracle text can be found using the Gatherer card database at Gatherer.Wizards.com.
108.2 When a rule or text on a card refers to a "card," it means only a Magic card. Most Magic games use only traditional Magic cards, which measure approximately 2.5 inches (6.3 cm) by 3.5 inches (8.8 cm). Certain formats also use nontraditional Magic cards, oversized cards that may have different backs. Tokens aren’t considered cards—even a card that represents a token isn’t considered a card for rules purposes.
108.2a In the text of spells or abilities, the term "card" is usually used to refer to a card that’s not on the battlefield or on the stack, such as a creature card in a player’s hand. The term "card" can also refer to a card in any zone that’s moving "from anywhere." On rare occasions, the text of a spell or ability may refer to a nontoken permanent as a "card . . . on the battlefield." For more information, see section 4, "Zones."
108.3 The owner of a card in the game is the player who started the game with it in his or her deck. If a card is brought into the game from outside the game rather than starting in a player’s deck, its owner is the player who brought it into the game. If a card starts the game in the command zone, its owner is the player who put it into the command zone to start the game. Legal ownership of a card in the game is irrelevant to the game rules except for the rules for ante. (See rule 407.)
108.3a In a Planechase game using the single planar deck option, the planar controller is considered to be the owner of all cards in the planar deck. See rule 901.6.
108.3b Some spells and abilities allow a player to take cards he or she owns from outside the game and bring them into the game. (See rule 400.10b.) If a card outside that game is involved in a Magic game, its owner is determined as described in rule 108.3. If a card outside that game is in the sideboard of a Magic game (see rule 100.4), its owner is considered to be the player who started the game with it in his or her sideboard. In all other cases, the owner of a card outside the game is its legal owner.
108.4 A card doesn’t have a controller unless that card represents a permanent or spell; in those cases, its controller is determined by the rules for permanents or spells. See rules 110.2 and 111.2.
108.4a If anything asks for the controller of a card that doesn’t have one (because it’s not a permanent or spell), use its owner instead.
108.5 Nontraditional Magic cards can’t start the game in any zone other than the command zone (see rule 408). If an effect would bring a nontraditional Magic card into the game from outside the game, it doesn’t; that card remains outside the game.
108.6 For more information about cards, see section 2, "Parts of a Card."