Minecraft wiki entry for Predicate, associated text: random_chance_with_looting—Generates a random number between 0.0 and 1.0, and checks if it is less than a specified value which has been affected by the level of Looting on the killer entity. Invokable from advancements and loot tables, and fails[verify] when invoked from anything else.
 chance: Base success rate.
 looting_multiplier: Looting adjustment to the base success rate. Formula is chance + (looting_level * looting_multiplier).