Alterguardian Phase1

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

Overview

The alterguardian_phase1 prefab defines the first phase of the Alterguardian boss in DST. It sets up a large, aggressive entity with rolling mechanics, shield phases, and gestalt summoning. This prefab uses multiple post-initializers (common_postinit_basic, common_postinit_rift, riftgestaltfn) to support variants (standard, lunar rift, and gestalt), each adjusting stats, visuals, and components. The core logic includes dynamic retargeting, collision handling, music triggering, and camera focus support.

Key responsibilities:

• Initialization of combat, health, locomotion, and timer components.
• Definition of boss behavior via custom functions (Retarget, KeepTarget, teleport_override_fn).
• Support for three variants (basic, lunar rift, and gestalt) with distinct assets and behaviors.

Usage example

-- Create standard Alterguardian Phase1
local boss = Prefab("alterguardian_phase1", fn, assets, prefabs)

-- Spawn the boss at a specific location
local inst = SpawnPrefab("alterguardian_phase1")
if inst ~= nil then
    inst.Transform:SetPosition(x, y, z)
end

Dependencies & tags

Components used:
locomotor, health, combat, sanityaura, lootdropper, inspectable, knownlocations, timer, teleportedoverride, drownable, hauntable, focalpoint (via TheFocalPoint), colouraddersync (local rift only), planarentity, planardamage, gestaltcapturable (riftgestalt only)

Tags added:
brightmareboss, epic, hostile, largecreature, mech, monster, noepicmusic, scarytoprey, soulless, lunar_aligned
(Additional tags for rift/gestalt variants: FX, brightmare, NOCLICK, nointerpolate)

Properties

Property	Type	Default Value	Description
inst._is_shielding	boolean	nil	True when the boss is in shield mode, absorbing damage.
inst._collisions	table	nil	Tracks recently collided entities during roll phase.
inst._playingmusic	boolean	false	Whether boss music is currently playing.
inst._start_sleep_time	number	nil	Timestamp when sleep began, used to regain health on wake.
inst.scrapbook_adddeps	table	See source	Dependencies for scrapbook entries.
inst.scrapbook_damage	table	[damage1, damage3]	Damage values shown in scrapbook.
inst.scrapbook_maxhealth	number	Sum of all phase healths	Total health pool shown in scrapbook.

Main functions

EnableRollCollision(enable)

• Description: Enables or disables collision callbacks for the rolling state. When enabled, the boss detects collisions with valid targets and performs on-collision effects (e.g., damage, sound).
• Parameters: enable (boolean) – whether to activate collision callbacks.
• Returns: Nothing.

EnterShield(inst)

• Description: Activates the boss’s shield mode, setting health absorption and triggering gestalt summoning if not on cooldown.
• Parameters: inst (entity instance) – the boss entity.
• Returns: Nothing.

ExitShield(inst)

• Description: Deactivates the boss’s shield mode, resetting health absorption to zero.
• Parameters: inst (entity instance) – the boss entity.
• Returns: Nothing.

SetNoMusic(inst, val)

• Description: Adds or removes the nomusic tag on the boss and triggers music update logic.
• Parameters: inst (entity instance), val (boolean) – whether to disable music.
• Returns: Nothing.

Retarget(inst)

• Description: Searches for new valid targets within range that satisfy tag conditions (_combat, excluding INLIMBO/playerghost, and having one of character/monster/shadowminion). Returns the first valid target found.
• Parameters: inst (entity instance).
• Returns: newtarget (entity) or nil. Also returns a true flag when a new target is found.
• Error states: Returns nil if no eligible target is found or the current target remains valid.

DoGestaltSummon(inst)

• Description: Spawns a variable number of gestalt minions in a ring around the boss, using timing delays and randomized positions. Also plays a summoning FX and starts the summon cooldown timer.
• Parameters: inst (entity instance).
• Returns: Nothing.

teleport_override_fn(inst)

• Description: Calculates a safe destination position after teleportation, attempting to find a walkable offset within a radius.
• Parameters: inst (entity instance).
• Returns: Vector3 – destination position, or current position if no valid offset found.

Inspect_boss(inst)

• Description: Returns status string "DEAD" if the boss is in the dead state tag.
• Parameters: inst (entity instance).
• Returns: "DEAD" or nil.

commonfn(common_postinit, server_postinit)

• Description: Main constructor function used to build the base entity with shared logic. Invoked by all three prefab variants via wrapper functions (fn, riftfn, riftgestaltfn).
• Parameters: common_postinit (function, optional), server_postinit (function, optional) – callbacks for variant-specific setup.
• Returns: inst (entity instance).

Events & listeners

• Listens to:

  • "musicdirty" – triggers OnMusicDirty(inst).
  • "attacked" – triggers OnAttacked(inst, data) (regains health, suggests new target, plays hit sound).
  • "phasetransition" – triggers OnPhaseTransition(inst) (spawns Phase2).
  • "blocked" – triggers play_custom_hit(inst).
  • "timerdone" – triggers on_timer_finished(inst, data).
  • "camerafocusdirty" (client-only) – triggers rift_OnCameraFocusDirty(inst).
  • "onremove" (internal for focalpoint/OnMusicDirty).

• Pushes:

  • "triggeredevent" – for music start/stop (via ThePlayer:PushEvent(...)).
  • "startspawnanim" – via inst:PushEvent(...).
  • "healthdelta" – via Health:DoDelta (inherited from component).
  • "attacked" – via OnPhaseTransition (when spawning Phase2, sets target).
  • "endloop" – on FX cleanup (spawn_warning:PushEvent("endloop")).