create_artifact_crown_effect

create_artifact_crown_effect = {
	# Get the character the artifact is being made for.
	$OWNER$ = { save_scope_as = owner }
	$SMITH$ = { save_scope_as = goldsmith }
	save_adventurer_location_effect = yes

	hidden_effect_new_object = {
		# Get artifact quality, wealth, materials, and decorations
		get_artifact_quality_effect = yes
		get_artifact_wealth_effect = yes

		# Create the artifact
		if = {
			limit = { exists = scope:adventurer }
			create_artifact = {
				name = artifact_crown_name
				description = placeholder # Will be updated in the post-creation effects
				template = crown_wearable_template
				visuals = crown
				type = helmet
				modifier = artifact_placeholder_modifier
				wealth = scope:wealth
				quality = scope:quality
				save_scope_as = newly_created_artifact
				history = {
					location = ROOT.capital_province
					actor = scope:adventurer
					recipient = scope:owner
					type = given
				}
			}
		}
		else = {
			create_artifact = {
				name = artifact_crown_name
				creator = scope:goldsmith
				description = placeholder # Will be updated in the post-creation effects
				template = crown_wearable_template
				visuals = crown
				type = helmet
				modifier = artifact_placeholder_modifier
				wealth = scope:wealth
				quality = scope:quality
				save_scope_as = newly_created_artifact
			}
		}

		scope:newly_created_artifact = {
			# Get gem type if necessary and update description
			get_artifact_feature_references_effect = yes
			set_artifact_description = artifact_crown_description

			# Crowns with high rarity get more modifiers
			if = {
				limit = {
					rarity = illustrious
				}
				add_2_scaled_artifact_modifier_rulership_effect = yes
				add_scaled_artifact_modifier_majesty_effect = yes
				add_scaled_artifact_modifier_minor_prestige_effect = yes
			}
			else_if = {
				limit = {
					rarity = famed
				}
				add_2_scaled_artifact_modifier_rulership_effect = yes
				add_scaled_artifact_modifier_majesty_effect = yes
				add_scaled_artifact_modifier_minor_prestige_effect = yes
			}
			else_if = {
				limit= {
					rarity = masterwork
				}
				add_scaled_artifact_modifier_minor_prestige_effect = yes
				add_scaled_artifact_modifier_rulership_effect = yes
			}
			else_if = {
				limit= {
					rarity = common
				}
				add_scaled_artifact_modifier_minor_prestige_effect = yes
				add_scaled_artifact_modifier_rulership_effect = yes
			}

			set_variable = {
				name = quality
				value = scope:quality
			}
			set_variable = {
				name = wealth
				value = scope:wealth
			}
		}
	}
}

As written in game/common/scripted_effects/00_ep1_artifact_creation_effects.txt.