Designate Heir

is_shown = scope:recipient = {
	is_child_of = scope:puppet_or_actor
}
NOR = {
	scope:recipient = scope:puppet_or_actor.designated_heir
	scope:recipient = scope:puppet_or_actor
}
scope:puppet_or_actor = {
	trigger_if = {
		limit = {
			is_roman_emperor_primary_title_trigger = no
		}
		custom_description = {
			text = dynasty_member_leads_election
			NAND = {
				primary_title ?= {
					has_title_law_flag = elective_succession_law
				}
				dynasty ?= primary_heir.dynasty
			}
		}
	}
}

As written in game/common/character_interactions/00_heir.txt.

trigger_if = {
	limit = {
		exists = scope:recipient
	}
	scope:recipient = {
		is_eunuch_trigger = no
		NOR = {
			has_trait = disinherited
			has_trait = devoted
			has_trait = order_member
			has_trait = bastard
		}
		house ?= scope:puppet_or_actor.house
	}
}
scope:puppet_or_actor = {
	can_designate_heir_trigger = yes
	trigger_if = {
		limit = {
			government_has_mechanic = administrative
			government_has_flag = government_has_influence
		}
		prestige >= designate_heir_admin_prestige_cost
		influence >= designate_heir_admin_influence_cost
		custom_tooltip = {
			text = valid_co_emperor_candidate_liege_trigger
			scope:recipient.top_liege = scope:puppet_or_actor.top_liege
		}
	}
	trigger_else_if = {
		limit = {
			NOR = {
				government_has_flag = government_is_mandala
				government_has_flag = government_is_landless_adventurer
			}
		}
		prestige >= designate_heir_cost
	}
	trigger_else = { }
	trigger_if = {
		limit = {
			government_has_flag = government_is_landless_adventurer
			exists = scope:recipient
		}
		scope:recipient = {
			is_adult = yes
		}
	}
	trigger_if = {
		limit = {
			government_has_flag = government_is_mandala
		}
		piety >= designate_heir_cost
	}
	trigger_if = {
		limit = {
			NOT = {
				scope:puppet_or_actor.primary_heir ?= scope:recipient
			}
		}
		custom_tooltip = {
			text = designate_heir_interaction.tt.currently_coruling
			NOT = {
				has_diarchy_active_parameter = diarchy_is_co_rulership
			}
		}
	}
}

As written in game/common/character_interactions/00_heir.txt.

on_accept = scope:puppet_or_actor = {
	send_interface_toast = {
		type = event_toast_effect_neutral
		title = designate_heir_interaction_notification
		left_icon = scope:puppet_or_actor
		right_icon = scope:recipient
		set_designated_heir = scope:recipient
	}
}
notify_puppeteer_of_outcome_effect = {
	TYPE = event_toast_effect_neutral
	TITLE = designate_heir_interaction_notification_puppeteer
}
on_auto_accept = scope:recipient = {
	trigger_event = char_interaction.0120
}

As written in game/common/character_interactions/00_heir.txt.