Historical Rules · 17 November 2023
Rule 122.1g
Official source text from the 17 November 2023 Rules release
The number of defense counters on a battle on the battlefield indicates how much defense it has. A battle with 0 defense is put into its owner’s graveyard if it isn’t the source of an ability that has triggered but not yet left the stack. This state-based action doesn’t use the stack. See rule 704.