murder_failure_effect

murder_failure_effect = {
 	# Add Watchful Modifier to the target
	scope:target = {
		add_character_modifier = {
			modifier = watchful_modifier
			days = watchful_modifier_duration
		}
	}
	# If the attempt was discovered, process the consequences of that.
	if = {
		limit = { exists = scope:scheme_discovered }
		# If we're a clan this affects unity
		## Landed victims cost more unity.
		if = {
			limit = {
				scope:target = { is_landed = yes }
			}
			add_clan_unity_interaction_effect = {
				CHARACTER = scope:owner
				TARGET = scope:target
				VALUE = medium_unity_loss
				DESC = clan_unity_murder_attempted.desc
				REVERSE_NON_HOUSE_TARGET = no
			}
		}
		## For unlanded characters, we don't care as much, but you still lose some.
		else = {
			add_clan_unity_interaction_effect = {
				CHARACTER = scope:owner
				TARGET = scope:target
				VALUE = minor_unity_loss
				DESC = clan_unity_murder_attempted.desc
				REVERSE_NON_HOUSE_TARGET = no
			}
		}
		## Tag scope:owner with a separate scope for portraits...
		scope:owner = {
			save_scope_as = owner_to_reveal
			# ... and apply a little dread.
			add_dread = minor_dread_gain
		}
		## Point out that yeah, attempted murder will sour someone's opinion of you.
		attempted_murder_opinion_effect = {
			VICTIM = scope:target
			MURDERER = scope:owner
		}
	}
	# Otherwise, we just add a murder attempt secret.
	else = {
		# Make sure we don't inadvertently reveal the scheme to the target.
		if = {
			limit = { this = scope:owner }
			scope:owner = {
				add_secret = {
					type = secret_murder_attempt
					target = scope:target
				}
			}
		}
	}
	# Lastly, if our imaginary friend put us up to this, then we address that.
	scope:owner = {
		if = {
			limit = {
				any_owned_story = {
					type = story_cycle_imaginary_friend
					var:imaginary_friend_murder_target ?= scope:target
				}
			}
			trigger_event = {
				id = bp2_yearly.2024
				days = 4
			}
		}
	}
}

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