portrait_wear_helmet_trigger

portrait_wear_helmet_trigger = { # Different from Armor, as (crowned) Kings and Emperors should show their crowns!
	exists = this
	trigger_if = {
		limit = { exists = involved_activity }
		involved_activity = {
			NOR = {
				has_activity_type = activity_hunt
				has_activity_type = activity_pilgrimage
				has_activity_type = activity_roaming
			}
		}
	}
	is_incapable = no
	is_imprisoned = no
	NOT = { has_court_position = court_astrologer_court_position }
	trigger_if = {
		limit = { portrait_sickness_trigger = yes }
		is_in_army = yes
	}
	OR = {
		# Adventurers
		AND = {
			is_ruler = yes
			government_has_flag = government_is_landless_adventurer
			has_realm_law = camp_purpose_mercenaries
		}
		# Military Orders
		# Rank-and-file military order members only wear helmets when actively fighting
		# (commanding an army or riding out as a knight). Otherwise they're shown in their
		# tonsured monastic form. Mirrors the commanding-army / knight_army logic used for
		# regular knights & marshals below. NOTE: portrait_wear_armor_trigger still lets
		# them wear their armor at all times, per the military-order aesthetic.
		AND = {
			has_trait = order_member
			OR = {
				is_commanding_army = yes
				exists = knight_army
			}
		}
		# Commanding and lower than a King or uncrowned
		AND = {
			is_commanding_army = yes
			OR = {
				is_landed_or_landless_administrative_or_theocratic = no
				AND = {
					exists = primary_title
					OR = {
						primary_title.tier < tier_kingdom
						portrait_wear_no_crown_trigger = yes
					}
				}
			}
		}
		# Knight in an army
		exists = knight_army
		# Non-Council Knight lower than King and liege is at war
		AND = {
			is_knight = yes
			is_councillor = no
			OR = {
				is_landed_or_landless_administrative_or_theocratic = no
				AND = {
					exists = primary_title
					primary_title.tier < tier_kingdom
					liege = { is_at_war = yes }
				}
			}
			NAND = {
				is_ruler = no
				government_has_flag = government_is_landless_adventurer
				liege ?= {
					is_at_war = no
					NOT = { has_realm_law = camp_purpose_mercenaries }
				}
			}
		}
		# Marshal lower than Duke
		AND = {
			has_council_position = councillor_marshal
			OR = {
				is_landed_or_landless_administrative_or_theocratic = no
				primary_title.tier < tier_duchy
			}
		}
		has_character_flag = wear_armor
		# Serving Varangian
		has_character_flag = is_currently_varangian
		# In a Duel
		has_character_flag = single_combat_duel_armor
		# In a Tournament
		activity_tournament_armor_trigger = yes
		AND = { # In case these characters become landed they should stop wearing armor
			has_character_flag = military_outfit
			is_ruler = no
		}
		# Military style governor
		AND = {
			is_independent_ruler = no
			government_allows = merit
			OR = {
				vassal_contract_has_flag = province_military
				vassal_contract_has_flag = celestial_grand_marshal_obligation
				AND = {
					has_council_position = councillor_marshal
					liege = {
						OR = {
							AND = {
								is_independent_ruler = yes
								highest_held_title_tier >= tier_kingdom
							}
							tgp_is_ceremonial_liege_trigger = yes
						}
					}
				}
			}
			is_adult = yes
			trigger_if = {
				limit = { has_trait = devoted }
				rite = { rite_has_parameter = clergy_can_fight }
			}

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