has_access_to_claim_throne_scheme_trigger

has_access_to_claim_throne_scheme_trigger = {
	OR = {
		has_perk = meritocracy_perk
		AND = {
			is_diarch_of_target = $TARGET$
			$TARGET$ = {
				NOT = { has_diarchy_parameter = can_be_instantly_dismissed }
			}
		}
		AND = {
			is_powerful_vassal_of = $TARGET$
			any_character_struggle = {
				involvement = involved
				has_struggle_phase_parameter = unlocks_claim_throne_for_powerful_vassals
				is_secondary_character_involvement_involved_trigger = {
					CHAR = $TARGET$
				}
			}
		}
		AND = {
			any_character_struggle = {
				involvement = involved
				has_struggle_phase_parameter = unlocks_claim_throne_for_all
				is_secondary_character_involvement_involved_trigger = {
					CHAR = $TARGET$
				}
			}
		}
		AND = {
			exists = title:d_sunni.holder
			is_vassal_of = title:d_sunni.holder
			any_character_struggle = {
				involvement = involved
				has_struggle_phase_parameter = unlocks_claim_throne_for_caliph_vassals
			}
		}
		has_character_flag = confederation_claim_throne
	}
	trigger_if = {
		limit = {
			government_has_flag = government_is_celestial
		}
		NOT = {
			any_liege_or_above = { has_title = title:h_china }
		}
	}
}

As written in game/common/scripted_triggers/00_scheme_triggers.txt.