vassal_would_join_rebel_faction_tyranny_trigger

vassal_would_join_rebel_faction_tyranny_trigger = {
	NOR = {
		# Isn't lover of liege
		has_relation_lover = scope:liege_temp
		# Isn't friend of liege
		has_relation_friend = scope:liege_temp
		# Isn't ally of liege
		is_allied_to = scope:liege_temp
		# Isn't heir of liege
		is_primary_heir_of = scope:liege_temp
		# Isn't hooked by liege
		scope:liege_temp = { has_strong_hook = prev }
		# Not cowed
		has_dread_level_towards = {
			target = scope:liege_temp
			level = 2
		}
		# Doesn't hate rebel's faith
		faith = {
			faith_hostility_level = {
				target = scope:rebel_temp.faith
				value >= faith_hostile_level
			}
		}
	}
	OR = {
		# it's not legal!
		ai_honor >= high_positive_ai_value
		# who cares? I believe this will not happen on me
		scope:liege_temp = {
			has_trait = kinslayer
		}
		trigger_if = {
			limit = { is_child_of = scope:liege_temp }
			is_child_of = scope:rebel_temp
		}
		trigger_else_if = {
			limit = { is_close_family_of = scope:liege_temp }
			is_close_family_of = scope:rebel_temp
		}
		trigger_else_if = {
			limit = { exists = house scope:liege_temp.house ?= house }
			scope:rebel_temp.house ?= house
		}
		trigger_else = {
			always = yes
		}
	}
	OR = {
		# Is an honorable person
		ai_honor >= 25
		# Doesn't hate the rebel
		trigger_if = {
			limit = {
				has_game_rule = very_hard_difficulty
				scope:liege_temp = { is_ai = no }
			}
			opinion = {
				target = scope:rebel_temp
				value >= 0
			}
		}
		trigger_else_if = {
			limit = {
				has_game_rule = hard_difficulty
				scope:liege_temp = { is_ai = no }
			}
			opinion = {
				target = scope:rebel_temp
				value >= 20
			}
		}
		trigger_else = {
			opinion = {
				target = scope:rebel_temp
				value >= 40
			}
		}
	}
}

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