Trap Vines

Based on game build 714014 | Last updated: 2026-03-07

Overview

trap_vines is a deployable environmental trap prefab that functions as an automated combat trigger. When active, it periodically scans the surrounding area for valid targets within its AOE radius using the combat, planardamage, and damagetypebonus components. Upon detecting a moving, non-ally target, it applies a temporary movement speed reduction via the locomotor component and deals damage. The trap exists for a fixed duration before naturally despawning, and it persists state across world saves via OnSave/OnLoad callbacks. It also uses a companion trap_vines_base_fx prefab to render visual effects anchored to the trap.

Usage example

-- Deploy a trap at world position (x, y, z)
local trap = SpawnPrefab("trap_vines")
if trap and TheWorld.ismastersim then
    trap.Transform:SetPosition(x, y, z)
    -- The trap will auto-initialize via its OnInit callback
end

Dependencies & tags

Components used: combat, planardamage, damagetypebonus, locomotor, timer, follower Tags: Adds trap, trap_vines, NOCLICK; checks player, flying, ghost, companion, shadowminion, playerghost, FX, INLIMBO, DECOR, notarget, debuffed. Prefabs referenced: trap_vines_base_fx

Properties

Property	Type	Default Value	Description
AOE_RADIUS	number	1	Base radius for target detection.
AOE_RANGE_PADDING	number	3	Extra padding added to detection radius.
variation	number	math.random(3)	Variant ID (1, 2, or 3) controlling animation selection.
_task	task or nil	nil	Reference to the periodic update task (OnUpdate).
_base	entity or nil	nil	The attached visual FX entity (trap_vines_base_fx).
caster	entity or nil	nil	Optional caster (player) that triggered the trap, used for ally checks.
sound	boolean or nil	nil	Tracks whether the looped sound is playing.

Main functions

OnUpdate(inst)

• Description: The core periodic task that scans for valid targets within the trap's AOE, applies a movement debuff, and triggers damage on moving entities.
• Parameters: inst (entity) — the trap instance.
• Returns: Nothing.
• Error states: Safely handles invalid or removed targets; skips entities not visible, outside hit range, or tagged as allies (including player companions and followers).

TryDoDamage(inst, target)

• Description: Attempts to deal damage to a target if it hasn't been hit recently (based on TUNING.TRAP_VINES_HIT_COOLDOWN).
• Parameters: inst (entity), target (entity) — the entity to damage.
• Returns: true if damage was dealt, nil otherwise.
• Error states: Returns early without damage if the target was recently hit (track maintained in TARGETS table).

ApplyDebuff(inst, target)

• Description: Applies a temporary movement speed reduction to a target and cancels any existing debuff on it.
• Parameters: inst (entity), target (entity).
• Returns: Nothing.
• Error states: Only applies if the target has a locomotor component; debuff is canceled when the target is removed or after 0.2 seconds.

DespawnTrap(inst)

• Description: Initiates the trap’s visual despawn animation and removes it from the world. Cancels pending decay timer if active.
• Parameters: inst (entity).
• Returns: Nothing.
• Error states: Skips FX animation cleanup if _base is nil; sets persists = false to avoid saving.

StartSoundLoop(inst)

• Description: Starts the looped sound effect if not already playing.
• Parameters: inst (entity).
• Returns: Nothing.

OnTimerDone(inst, data)

• Description: Callback fired when the decay timer finishes; triggers DespawnTrap.
• Parameters: inst (entity), data (table) — timer data; checks data.name == "decay".
• Returns: Nothing.

OnInit(inst)

• Description: Initialization handler, called after a short delay; spawns visual FX, plays spawn animation, and starts the periodic update task.
• Parameters: inst (entity).
• Returns: Nothing.

OnSave(inst, data)

• Description: Serializes the trap's variation and sound state for world persistence.
• Parameters: inst (entity), data (table) — table to populate.
• Returns: Nothing.

OnLoad(inst, data)

• Description: Restores trap state after loading; reinitializes the update task, visual FX, and animation if applicable.
• Parameters: inst (entity), data (table or nil).
• Returns: Nothing.

Events & listeners

• Listens to: timerdone — fires OnTimerDone when the decay timer completes.
• Listens to: onremove — on targets (via ForgetTarget, RemoveDebuff) to clean up state when they are removed.
• Listens to: animover — used during despawn to call inst.Remove after animation finishes.
• Pushes: None.