Skip to main content

Shadow Rookbrain

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

Overview​

Shadow_RookBrain is the behavior tree controller for the Shadow Rook entity—a boss-stage chesspiece in DST's Beeffalo/Caves content. It orchestrates movement and actions via a priority-based behavior tree. The brain coordinates chasing the nearest valid player, maintaining orientation toward a target (to simulate facing), periodically taunting when idle, and automatically despawning after a fixed duration. It depends on the combat and health components for target tracking and state validation.

Usage example​

local inst = CreateEntity()
inst:AddTag("shadowpiece")
inst:AddComponent("combat")
inst:AddComponent("health")
inst:AddBrain("shadow_rookbrain")
inst.components.combat.target = some_player
inst.components.health:SetHealth(100)

Dependencies & tags​

Components used: combat, health
Tags: Checks notarget, playerghost for target filtering; does not add or remove tags itself.

Properties​

PropertyTypeDefault ValueDescription
_shouldchasebooleanfalseInternal state indicating whether the rook should be chasing. Updated by ShouldChase.

Main functions​

OnStart()​

  • Description: Initializes the behavior tree for the Shadow Rook. Constructs a root PriorityNode with four main behavioral branches: chasing, facing/taunting, wandering/despawning, and fallback wander.
  • Parameters: None.
  • Returns: Nothing.
  • Error states: None. Behavior tree setup is guaranteed on first activation.

ShouldChase(self)​

  • Description: Evaluates whether the rook should transition into a chase state. Considers current combat target, cooldown status, and distance relative to attack range.
  • Parameters: self (table) — the brain instance.
  • Returns: boolean — true if the rook should begin or continue chasing; false otherwise.
  • Error states: None. Uses combat.target, combat:HasTarget(), combat:InCooldown(), combat.attackrange, and inst:IsNear().

Events & listeners​

  • Pushes: despawn — fired after TUNING.SHADOW_CHESSPIECE_DESPAWN_TIME seconds via the behavior tree. This event triggers the entity’s removal logic.