An object is any concrete "thing" in a game of Magic: an ability on the stack, a card, a copy of a card, a token, a spell, a permanent, or an emblem. No card currently references objects as such, only particular types of objects.
An object can have many characteristics: Name, mana cost, color, card type, subtype, supertype, rules text, abilities, power and toughness, loyalty, hand modifier and life modifier. Any other information regarding the object is not considered a characteristic, but rather an attribute or a property.
From the Comprehensive Rules (Guilds of Ravnica (October 5, 2018))
- 109. Objects
- 109.1. An object is an ability on the stack, a card, a copy of a card, a token, a spell, a permanent, or an emblem.
- 109.2. If a spell or ability uses a description of an object that includes a card type or subtype, but doesn’t include the word “card,” “spell,” “source,” or “scheme,” it means a permanent of that card type or subtype on the battlefield.
- 109.2a If a spell or ability uses a description of an object that includes the word “card” and the name of a zone, it means a card matching that description in the stated zone.
- 109.2b If a spell or ability uses a description of an object that includes the word “spell,” it means a spell matching that description on the stack.
- 109.2c If a spell or ability uses a description of an object that includes the word “source,” it means a source matching that description—either a source of an ability or a source of damage—in any zone. See rule 609.7.
- 109.2d If an ability of a scheme card includes the text “this scheme,” it means the scheme card in the command zone on which that ability is printed.
- 109.3. An object’s characteristics are name, mana cost, color, color indicator, card type, subtype, supertype, rules text, abilities, power, toughness, loyalty, hand modifier, and life modifier. Objects can have some or all of these characteristics. Any other information about an object isn’t a characteristic. For example, characteristics don’t include whether a permanent is tapped, a spell’s target, an object’s owner or controller, what an Aura enchants, and so on.
- 109.4. Only objects on the stack or on the battlefield have a controller. Objects that are neither on the stack nor on the battlefield aren’t controlled by any player. See rule 108.4. There are five exceptions to this rule:
- 109.4a An emblem is controlled by the player that puts it into the command zone. See rule 113, “Emblems.”
- 109.4b In a Planechase game, a face-up plane or phenomenon card is controlled by the player designated as the planar controller. This is usually the active player. See rule 901.6.
- 109.4c In a Vanguard game, each vanguard card is controlled by its owner. See rule 902.6.
- 109.4d In an Archenemy game, each scheme card is controlled by its owner. See rule 904.7.
- 109.4e In a Conspiracy Draft game, each conspiracy card is controlled by its owner. See rule 905.5.
- 109.5. The words “you” and “your” on an object refer to the object’s controller, its would-be controller (if a player is attempting to play, cast, or activate it), or its owner (if it has no controller). For a static ability, this is the current controller of the object it’s on. For an activated ability, this is the player who activated the ability. For a triggered ability, this is the controller of the object when the ability triggered, unless it’s a delayed triggered ability. To determine the controller of a delayed triggered ability, see rules 603.7d–f.
From the glossary of the Comprehensive Rules (Guilds of Ravnica (October 5, 2018))
- Objects can deal “damage” to creatures, planeswalkers, and players. This is generally detrimental to the object or player that receives that damage. See rule 119, “Damage.”