Bargain Fealty

is_available = is_at_war = yes
any_character_struggle = {
	involvement = involved
	struggle_can_access_unlocks_bargain_fealty_interaction_trigger = yes
}
trigger_if = {
	limit = {
		is_ai = yes
	}
	is_imprisoned = no
}
top_liege ?= this
is_shown = scope:actor = {
	any_character_war = {
		primary_defender ?= scope:actor
		is_war_leader = scope:actor
	}
	trigger_if = {
		limit = {
			scope:recipient = {
				is_landless_ruler = no
			}
		}
		tier_difference = {
			target = scope:recipient
			value <= -1
		}
	}
	trigger_else = {
		tier_difference = {
			target = scope:recipient
			value <= -2
		}
	}
}
scope:recipient = {
	NOT = {
		this = scope:actor
	}
	primary_title ?= {
		is_mercenary_company = no
	}
}

As written in game/common/character_interactions/03_fp2_interactions.txt.

scope:actor = {
	custom_tooltip = {
		text = bargain_fealty_interaction_valid_tt
		any_character_war = {
			is_war_leader = scope:actor
			primary_defender = scope:actor
			NOT = {
				using_cb = fp2_border_raid
			}
			NOT = {
				using_cb = county_struggle_cb
			}
		}
	}
	any_character_struggle = {
		involvement = involved
		has_struggle_phase_parameter = unlocks_bargain_fealty_interaction
	}
}
scope:recipient = {
	custom_tooltip = {
		text = bargain_fealty_interaction_neighbor_tt
		any_neighboring_and_across_water_top_liege_realm_owner = {
			this = scope:actor
		}
	}
	NOT = {
		is_at_war_with = scope:actor
	}
}
exists = scope:target

As written in game/common/character_interactions/03_fp2_interactions.txt.

on_accept = if = {
	limit = {
		exists = scope:target
	}
	scope:target = {
		hidden_effect = {
			set_called_to = scope:recipient
		}
		if = {
			limit = {
				is_attacker = scope:actor
			}
			add_attacker = scope:recipient
		}
		else = {
			add_defender = scope:recipient
		}
	}
	create_title_and_vassal_change = {
		type = swear_fealty
		save_scope_as = change
	}
	scope:actor = {
		change_liege = {
			liege = scope:recipient
			change = scope:change
		}
		resolve_title_and_vassal_change = scope:change
	}
	scope:actor = {
		stress_and_fulfillment_impact = {
			arrogant = medium_stress_impact_gain
			craven = medium_stress_impact_gain
		}
	}
	scope:recipient = {
		stress_and_fulfillment_impact = {
			greedy = medium_stress_impact_gain
			craven = medium_stress_impact_gain
		}
	}
}
else = {
	scope:actor = {
		send_interface_toast = {
			type = event_toast_effect_neutral
			title = war_ended_before_response
			left_icon = scope:recipient
		}
	}
}
add_clan_unity_interaction_effect = {
	CHARACTER = scope:actor
	TARGET = scope:recipient
	VALUE = medium_unity_gain
	DESC = clan_unity_bargained_fealty.desc
	REVERSE_NON_HOUSE_TARGET = no
}
on_decline = scope:actor = {
	trigger_event = char_interaction.0236
}
add_clan_unity_interaction_effect = {
	CHARACTER = scope:recipient
	TARGET = scope:actor
	VALUE = minor_unity_loss
	DESC = clan_unity_bargain_fealty_refusal.desc
	REVERSE_NON_HOUSE_TARGET = no
}

As written in game/common/character_interactions/03_fp2_interactions.txt.