A characteristic-defining ability is a kind of static ability that conveys information about an object's characteristics that would normally be found elsewhere on that object (such as in its mana cost, type line, or power/toughness box).
Characteristic-defining abilities are noteworthy because they are active at all times, even while not in play or outside of the game.
Some characteristic-defining abilities are:
- Changeling (grants every creature type.) e.g. Avian Changeling.
- Devoid (makes an object colorless, despite the presence of colored mana in the mana cost) e.g. Touch of the Void.
- Characteristic-Defining Ability
- A kind of static ability that conveys information about an object’s characteristics that would normally be found elsewhere on that object (such as in its mana cost, type line, or power/toughness box). See rule 604.3.
- 604.3. Some static abilities are characteristic-defining abilities. A characteristic-defining ability conveys information about an object’s characteristics that would normally be found elsewhere on that object (such as in its mana cost, type line, or power/toughness box) or overrides information found elsewhere on that object. Characteristic-defining abilities function in all zones. They also function outside the game.
- 604.3a A static ability is a characteristic-defining ability if it meets the following criteria: (1) It defines an object’s colors, subtypes, power, or toughness; (2) it is printed on the card it affects, it was granted to the token it affects by the effect that created the token, or it was acquired by the object it affects as the result of a copy effect or text-changing effect; (3) it does not directly affect the characteristics of any other objects; (4) it is not an ability that an object grants to itself; and (5) it does not set the values of such characteristics only if certain conditions are met.
- 706.9d When applying a copy effect that doesn’t copy a certain characteristic, retains an original value for a certain characteristic, or modifies the final value of a certain characteristic, any characteristic-defining ability (see rule 604.3) of the object being copied that defines that characteristic is not copied. If that characteristic is color, any color indicator (see rule 204) of that object is also not copied.
Example: Quicksilver Gargantuan is a creature that reads, “You may have Quicksilver Gargantuan enter the battlefield as a copy of any creature on the battlefield, except it’s 7/7.” Quicksilver Gargantuan enters the battlefield as a copy of Tarmogoyf, which has a characteristic-defining ability that defines its power and toughness. Quicksilver Gargantuan does not have that ability. It will be 7/7.