disburse_festival_piety_reward_effect

disburse_festival_piety_reward_effect = {
	if = {
		limit = {
			root.rite = {
				OR = {
					rite_has_parameter = piety_from_festivals_active
					AND = {
						rite_has_parameter = summer_festivals_active
						# Only during 'summer' (May 1st through July 31st).
						current_month >= 5
						current_month <= 7
					}
				}
			}
		}
		root = {
			add_piety = {
				value = 0

				if = {
					limit = {
						rite = { rite_has_parameter = summer_festivals_active }
						# Only during 'summer' (May 1st through July 31st).
						current_month >= 5
						current_month <= 7
					}
					add = major_piety_value
				}
				if = {
					limit = {
						rite = { rite_has_tenet = tenet_ritual_celebrations }
					}
					add = medium_piety_value
				}
				if = {
					limit = {
						rite = { rite_has_tenet = tenet_hedonistic }
					}
					add = medium_piety_value
				}
				if = {
					limit = {
						has_royal_court = yes
						has_dlc_feature = royal_court
						amenity_level = { target = court_food_quality value >= 5 }
					}
					multiply = 2.5
				}
				else_if = {
					limit = {
						has_royal_court = yes
						has_dlc_feature = royal_court
						amenity_level = { target = court_food_quality value >= 4 }
					}
					multiply = 2
				}
				else_if = {
					limit = {
						has_royal_court = yes
						has_dlc_feature = royal_court
						amenity_level = { target = court_food_quality value >= 3 }
					}
					multiply = 1.5
				}
				else_if = {
					limit = {
						has_royal_court = yes
						has_dlc_feature = royal_court
						amenity_level = { target = court_food_quality value >= 2 }
					}
					multiply = 1
				}
				else_if = {
					limit = {
						has_royal_court = yes
						has_dlc_feature = royal_court
						amenity_level = { target = court_food_quality value <= 1 }
					}
					multiply = 0.5
				}

				# Always give some piety, even if you completely cheaped out.
				min = medium_piety_value
			}
		}
	}
}

As written in game/common/scripted_effects/10_dlc_tgp_scripted_effects.txt.