give_legendary_building_heroic_tooltip_effect

give_legendary_building_heroic_tooltip_effect = { #50% chance
	# Chance to get legendary building
	if = {
		limit = {
			OR = {
				root = {
					locale_valid_for_legendary_buildings = yes
				}
				capital_province = { has_special_building_slot = no }
				any_sub_realm_barony = {
					title_province = { has_special_building_slot = no }
				}
			}
		}
		random = {
			chance = {
				value = 50
			}
			give_legendary_building_location_heroic_effect = yes
			set_variable = {
				name = legendary_reward_location
				value = scope:legendary_locale
			}
			set_variable = {
				name = legendary_figure
				value = scope:protagonist
			}
		}
	}
}

As written in game/common/scripted_effects/06_dlc_ce1_legend_effects.txt.