Historical Rules · 1 February 2010
Rule 112.1a
Official source text from the 1 February 2010 Rules release
An ability is a characteristic an object has that lets it affect the game. An object's abilities are defined by its rules text or by the effect that created it. Abilities can also be granted to objects by rules or effects. (Effects that do so use the words "has," "have," "gains," or "gain.") Abilities generate effects. (See rule 609, "Effects.")