can_create_rite_trigger

can_create_rite_trigger = {

	is_adult = yes
	is_at_war = no
	
	trigger_if = {
		limit = {
			is_clergy = no
			highest_held_title_tier = tier_county
			top_liege != this
		}
		custom_description = {
			text = "faith_creation_duchy_or_higher"
			highest_held_title_tier >= tier_duchy
		}
	}

	trigger_if = {
		limit = {
			rite = {
				rite_has_doctrine = doctrine_theocracy_temporal
			}
			is_clergy = no
			has_puppet_type = theological_agent_puppet
			# Allow Mandala God-Kings and Son of Heaven to create and edit rites freely
			trigger_if = {
				limit = {
					top_overlord = this
				}
				NOR = {
					government_has_flag = government_is_mandala
					tgp_has_access_to_ministry_trigger = yes
				}
			}
		}
		is_puppet_action_valid = puppet_trigger_can_create_rite
	}
	
	custom_description = {
		text = "character_is_not_real_head"
		faith.religious_head != root
	}

	custom_description = {
		text = "character_can_only_create_one_rite"
		NOT = { exists = var:has_created_a_faith }
	}

	trigger_if = {
		limit = {
			faith = { has_doctrine_parameter = unreformed }
		}

		NOT = {
			custom_description = {
				text = faith_has_been_reformed
				object = faith
				exists = faith.var:has_been_reformed
			}
		}

		trigger_if = {
			limit = {
				NOT = {
					has_character_flag = ignore_3_holy_site_rule
				}
			}
			# Empire Faith Gate: easier reformation path
			trigger_if = {
				limit = {
					empire_faith_gate_enabled_trigger = yes
				}
				custom_tooltip = {
					text = empire_faith_gate_reformation_piety_level
					piety_level >= 2
				}
				trigger_if = {
					limit = {
						government_has_flag = government_is_tribal
					}
					custom_tooltip = {
						text = empire_faith_gate_reformation_tribal_authority
						has_realm_law = tribal_authority_3
					}
				}
				custom_tooltip = {
					text = empire_faith_gate_reformation_holy_site
					faith = {
						any_holy_site_barony = {
							count >= 3
							county.holder = {
								faith = root.faith
							}
						}
					}
				}
			}
			# Vanilla: 3 holy sites
			trigger_else = {
				faith = {
					num_realm_holy_sites_faithful_holders = {
						CHARACTER = root
						COUNT = 3
					}
				}
			}
		}

		custom_tooltip = {
			text = faith_reformation_via_decision
			faith = {
				NOT = { has_variable = block_reformation_var }
			}
		}
	}
}

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