Alterguardian Phase2

Based on game build 714014 | Last updated: 2026-03-04

Overview

The alterguardian_phase2 prefab represents the second transformation stage of the Alter Guardian boss in DST. It functions as a combat-capable entity that dynamically spawns ring-shaped spike projectiles in patterns, interacts with players and monsters via its combat system, manages ambient music triggers based on player proximity, and regenerates health over time when the world sleeps. It transitions to Phase 3 upon receiving a phasetransition event. The prefab is instantiated through a constructor function fn() and relies heavily on external components for health, combat, locomotion, and AI behavior.

Usage example

This prefab is not typically created directly by modders but is spawned internally during the boss encounter:

local phase2 = SpawnPrefab("alterguardian_phase2")
phase2.Transform:SetPosition(x, y, z)
phase2.sg:GoToState("idle")

Modders may interact with its public methods:

-- Force a spike attack
phase2.DoSpikeAttack()

-- Disable ambient music
phase2:SetNoMusic(true)

Dependencies & tags

Components used: locomotor, health, combat, explosiveresist, sanityaura, lootdropper, inspectable, knownlocations, timer, teleportedoverride, drownable, hauntable.
Tags added: "brightmareboss", "epic", "hostile", "largecreature", "mech", "monster", "noepicmusic", "scarytoprey", "soulless", "lunar_aligned".

Properties

Property	Type	Default Value	Description
DoSpikeAttack	function	nil	Public method reference to trigger the spike attack sequence.
SetNoMusic	function	nil	Public method reference to toggle music presence via tag.
_musicdirty	net_event	nil	Network event used to sync music state across clients.
_playingmusic	boolean	false	Tracks whether music is currently playing for this instance.
_musictask	task	nil	Periodic task responsible for updating music state.
_loot_dropped	boolean	nil	Flag used during save/load to prevent duplicate loot drops.
_start_sleep_time	number	nil	Timestamp used to calculate health gained while sleeping.

Main functions

do_spike_attack(inst)

• Description: Spawns a randomized number of spike trails (alterguardian_phase2spiketrail) around the boss within a configurable range. Prioritizes nearby players, then other targetable entities, and finally picks random angles if needed.
• Parameters: inst (Entity) — the boss instance performing the attack.
• Returns: Nothing.
• Error states: Returns early if data is nil or no valid targets are found.

Retarget(inst)

• Description: Searches for a new combat target within a fixed radius, checking for valid tags and combat compatibility.
• Parameters: inst (Entity) — the boss instance.
• Returns: target (Entity or nil) — the first valid target found; true if a valid target was found (used by combat retarget logic).
• Error states: Returns nil only if no suitable target is found in range.

KeepTarget(inst, target)

• Description: Determines if the boss should maintain focus on a given target based on validity and distance.
• Parameters: inst (Entity), target (Entity) — the current target.
• Returns: true if the target is still valid and within MAX_CHASEAWAY_DIST_SQ; otherwise false.
• Error states: Returns false if CanTarget fails or the target is too far.

SetNoMusic(inst, val)

• Description: Adds or removes the "nomusic" tag and triggers a music dirty event to resynchronize music state.
• Parameters: val (boolean) — if true, disables music; otherwise enables it.
• Returns: Nothing.

teleport_override_fn(inst)

• Description: Calculates a valid teleport destination using walkable offsets near the current position.
• Parameters: inst (Entity) — the boss instance teleporting.
• Returns: Vector3 — the new position if a walkable offset is found; otherwise falls back to current position.
• Error states: May return the original position if no offset succeeds.

gain_sleep_health(inst)

• Description: Gradually restores health while the world is sleeping, up to ALTERGUARDIAN_PHASE2_MAXHEALTH.
• Parameters: inst (Entity) — the boss instance.
• Returns: Nothing.
• Error states: Resets _start_sleep_time in OnEntityWake; no health gain occurs if called outside a sleep period.

Events & listeners

• Listens to:
  • "phasetransition" → OnPhaseTransition — triggers transition to Phase 3.
  • "attacked" → OnAttacked — suggests the attacker as a new combat target.
  • "musicdirty" → OnMusicDirty (client only) — refreshes music task and state.
• Pushes: None directly (uses inst:PushEvent only in connected components or state graph).