If a battle has no player in the game designated as its protector and no attacking creatures are currently attacking that battle, that battle’s controller chooses an appropriate player to be its protector based on its battle type. If the battle has no battle type, its controller must be chosen. If no player can be chosen this way, the battle is put into its owner’s graveyard. See rule 310, “Battles.”
April 14, 2023 · March of the Machine
If a Siege’s controller is also its designated protector, that player chooses an opponent to become its protector. If no player can be chosen this way, the battle is put into its owner’s graveyard. See rule 310, “Battles.”
July 3, 2020 · Core Set 2021
rule 704.5x not present in this release
May 3, 2019 · War of the Spark
In a Planechase game, if a phenomenon card is face up in the command zone, and it isn’t the source of a triggered ability that has triggered but not yet left the stack, the planar controller planeswalks. See rule 901, “Planechase.”
January 25, 2019 · Ravnica Allegiance
In a Planechase game, if a phenomenon card is face up in the command zone, and it isn't the source of a triggered ability that has triggered but not yet left the stack, the planar controller planeswalks. See rule 901, "Planechase."
April 27, 2018 · Dominaria
In a Planechase game, if a phenomenon card is face up in the command zone, and it isn’t the source of a triggered ability that has triggered but not yet left the stack, the planar controller planeswalks. See rule 901, “Planechase.”
September 29, 2017 · Ixalan
rule 704.5x not present in this release
May 1, 2014 · Journey into Nyx
In a Planechase game, if a phenomenon card is face up in the command zone, and it isn’t the source of a triggered ability that has triggered but not yet left the stack, the planar controller planeswalks. See rule 901, “Planechase.”
February 1, 2014 · Born of the Gods
In a Planechase game, if a phenomenon card is face up in the command zone, and it isn’t the source of a triggered ability that has triggered but not yet left the stack, the planar controller planeswalks. See rule 901, "Planechase."
July 1, 2012 · Magic 2013
In a Planechase game, if a phenomenon card is face up in the command zone, and it isn't the source of a triggered ability that has triggered but not yet left the stack, the planar controller planeswalks. See rule 901, "Planechase."