469.1. Conquer: A player gains Control of a Battlefield they did not yet Score this turn.
469.1.a. In Modes of Play with teammates, Battlefields under the Control of a teammate during the scoring step of the Beginning Phase of a player's turn are also disqualified from being Scored through Conquer by any means by that player's team.
469.1.b. A player will gain control of a Battlefield after establishing Control.