mpo_nomad_duchy_invasion_war_ai_trigger

mpo_nomad_duchy_invasion_war_ai_trigger = {
	is_independent_ruler = yes
	is_at_war = no
	gold > 0
	NOT = {
		has_realm_law = uncrowned
	}
	has_realm_law = nomadic_authority_2
	OR = {
		#China is in division
		AND = {
			situation:dynastic_cycle ?= { situation_current_phase = situation_dynastic_cycle_phase_chaos }
			NOT = {
				exists = title:h_china.holder
			}
		}
		# Havsaran zud? Leave the steppe!
		capital_county ?= {
			any_county_situation_sub_region = {
				situation_sub_region_has_county = prev
				sub_region_current_phase = situation_steppe_havsarsan_zud_season
			}
		}
		#Landless and heavily herded
		AND = {
			is_landed = no
			domicile.herd >= 4000
		}
		#Family has held title without ascendance for a while
		AND = {
			ai_energy >= 0
			is_gurkhan = no
			sub_realm_size <= 3
			domicile ?= { herd <= two_thirds_max_herd_value }
			
			exists = $NOMAD$.house
			primary_title = {
				previous_holder ?= {
					house ?= $NOMAD$.house
				}
				any_past_holder = {
					count >= 2
					this != $NOMAD$
					house ?= $NOMAD$.house
					OR = {
						is_alive = yes
						time_since_death = {
							years <= 120
						}
					}
				}
			}
		}
	}
}

As written in game/common/scripted_triggers/mpo_scripted_triggers.txt.