Every distinct wording since 2010, newest first.
July 12, 2019 · Core Set 2020
A player may activate an activated ability any time they have priority.
February 1, 2010 · Worldwake
In a Vanguard game, each player begins the game with a starting life total of 20, as modified by his or her vanguard card's life modifier. See rule 902, "Vanguard."