noble_family_adoption_effect

noble_family_adoption_effect = {
	$ADOPTEE$ = {
		if = {
			limit = {
				exists = house.house_head
			}
			house.house_head = {  #We do this first, otherwise house head will already mean someone else.
				if = {
					limit = {
						$ADOPTER$.culture = { has_cultural_parameter = wider_adoption }
						$ADOPTEE$ = {
							culture = { has_cultural_parameter = wider_adoption }
							NOT = {
								any_parent = {
									is_alive = yes
									can_be_combatant_based_on_gender_trigger = { ARMY_OWNER = liege }
								}
							}
						}
					}
					add_opinion = {
						modifier = adopted_my_house_member_opinion
						opinion = 25
						target = $ADOPTER$
					}
				}
				else = {
					add_opinion = {
						modifier = adopted_my_house_member_opinion
						opinion = -25
						target = $ADOPTER$
					}
				}
				if = {
					limit = {
						has_hook_of_type = {
							type = house_head_hook
							target = $ADOPTEE$
						}
					}
					remove_hook = {
						type = house_head_hook
						target = $ADOPTEE$
					}
				}
			}
		}
	}
	$ADOPTER$ = {
		if = {
			limit = { scope:gold = yes }
			pay_short_term_gold = {
				target = $ADOPTEE$
				gold = $ADOPTER$.minor_gold_value
			}
		}
		if = {
			limit = { scope:hook = yes }
			use_hook = $ADOPTEE$
		}
		$ADOPTEE$ = { set_house = $ADOPTER$.house }
		# Zealous vassals *hate* you adopting a heretic
		house = {
			every_house_member = {
				custom = every_zealot_house_member_tt
				limit = {
					ai_zeal >= medium_positive_ai_value
					faith = { faith_hostility_level = { target = $ADOPTEE$.faith value >= faith_astray_level } }
					NOT = { this = $ADOPTER$ }
				}
				add_opinion = {
					modifier = adopted_new_house_member_opinion
					opinion = -20
					target = $ADOPTER$
				}
			}
			every_house_member = {
				custom = every_close_family_house_member_tt
				limit = {
					NOT = { this = $ADOPTER$ }
					is_close_family_of = $ADOPTER$
					NAND = {
						ai_zeal >= medium_positive_ai_value
						faith = { faith_hostility_level = { target = $ADOPTEE$.faith value >= faith_astray_level } }
					}
					NAND = {
						$ADOPTER$.culture = { has_cultural_parameter = wider_adoption }
						$ADOPTEE$ = {
							culture = { has_cultural_parameter = wider_adoption }
							NOT = {
								any_parent = {
									is_alive = yes
									can_be_combatant_based_on_gender_trigger = { ARMY_OWNER = liege }
								}
							}
						}
					}
				}
				add_opinion = {
					modifier = adopted_new_house_member_opinion
					opinion = -10
					target = $ADOPTER$
				}
			}
		}
	}
	$ADOPTEE$ = {
		#adopted should travel
		if = {
			limit = { exists = $ADOPTER$.capital_province }
			$ADOPTER$.capital_province = { save_scope_as = destination_province }
		}
		else_if = {
			limit = { exists = $ADOPTER$.host.capital_province }
			$ADOPTER$.host.capital_province = { save_scope_as = destination_province }
		}
		else_if = {
			limit = { exists = $ADOPTER$.domicile.domicile_location }
			$ADOPTER$.domicile.domicile_location = { save_scope_as = destination_province }
		}

As written in game/common/scripted_effects/07_dlc_ep3_scripted_effects.txt.