marriage_interaction_on_accept_effect

marriage_interaction_on_accept_effect = {
	#Use hook
	if = {
		limit = { always = scope:hook }
		scope:puppet_or_actor = {
			use_hook = scope:recipient
		}
		#To make sure betrothals can't be broken if a hook was used
		if = {
			limit = {
				OR = {
					scope:secondary_actor = { is_adult = no }
					scope:secondary_recipient = { is_adult = no }
				}
			}
			scope:secondary_actor = {
				set_variable = {
					name = hook_used_for_betrothal
					value = scope:secondary_recipient
				}
			}
		}
	}
	
	#Penalties for marrying a lowborn
	scope:puppet_or_actor = {
		if = {
			limit = {
				this = scope:secondary_actor # We check that you're marrying them yourself
				scope:secondary_recipient = { is_lowborn = yes }
			}
			# Vassal dispositions get aggy.
			## Actual effect applied in the on_marriage on_action.
			show_as_tooltip = {
				vassals_dislike_marry_lowborn_effect = {
					SPOUSE = scope:secondary_recipient
					RULER = scope:puppet_or_actor
				}
			}
			#Legitimacy loss for marrying a lowborn
			if = {
				limit = {
					is_valid_for_legitimacy_change = yes
					NOT = { rite = { rite_has_parameter = piety_from_marrying_lowborn_active } }
					NOT = { has_variable = lowborn_legitimacy_cooldown }
					OR = {
						NOT = { exists = primary_spouse }
						primary_spouse ?= scope:secondary_recipient
					}
				}
				if = {
					limit = { is_ai = no }
					send_interface_toast = {
						type = event_toast_effect_neutral
						title = married_lowborn_toast
						left_icon = scope:puppet_or_actor
						add_legitimacy = {
							value = medium_legitimacy_loss
							multiply = scope:puppet_or_actor.primary_title.tier
						}
					}
				}
				else = { # To avoid destroying polygamy AIs
					send_interface_toast = {
						type = event_toast_effect_neutral
						title = married_lowborn_toast
						left_icon = scope:puppet_or_actor
						add_legitimacy = { value = minor_legitimacy_loss }
					}
					hidden_effect = {
						set_variable = {
							name = lowborn_legitimacy_cooldown
							years = 10
						}
					}
				}
			}
		}
		else_if = { # If they're not a lowborn AND you and the recipient are both Nomad we may give you some Legitimacy
			limit = {
				this = scope:secondary_actor # We check that you're marrying them yourself
				scope:secondary_recipient = { is_lowborn = no }
				is_valid_for_nomadic_legitimacy_change = yes
				scope:recipient = { government_has_flag = government_is_nomadic }
				mpo_lower_nomad_authority_trigger = { CHARACTER = scope:recipient } # Only if recipient has higher Dominance than you
			}
			add_legitimacy = medium_legitimacy_gain
		}
	}
	scope:recipient = {
		if = {
			limit = {
				this = scope:secondary_recipient # We check that you're marrying them yourself
				scope:secondary_actor = { is_lowborn = yes }
			}
			# Vassal dispositions get aggy.
			## Actual effect applied in the on_marriage on_action.
			show_as_tooltip = {
				vassals_dislike_marry_lowborn_effect = {
					SPOUSE = scope:secondary_actor
					RULER = scope:recipient
				}
			}
			#Legitimacy loss for marrying a lowborn
			if = {
				limit = {
					is_valid_for_legitimacy_change = yes
					NOT = { rite = { rite_has_parameter = piety_from_marrying_lowborn_active } }
					NOT = { has_variable = lowborn_legitimacy_cooldown }
					OR = {
						NOT = { exists = primary_spouse }
						primary_spouse ?= scope:secondary_actor
					}
				}
				if = {
					limit = { is_ai = no }
					send_interface_toast = {
						type = event_toast_effect_neutral
						title = married_lowborn_toast
						left_icon = scope:recipient

As written in game/common/scripted_effects/00_marriage_interaction_effects.txt.