Krampusbrain

Based on game build 714014 | Last updated: 2026-02-27

Overview

krampusbrain.lua defines the behavior tree for the Krampus entity in Don't Starve Together. It orchestrates Krampus's core behaviors: stealing items from players, opening treasure chests when inventory is not full, fleeing from electric fences and players under certain conditions, chasing and attacking when provoked, and exiting the world after accumulating a greed threshold of items. It integrates with standard behavior tree utilities (behaviours/) and brain infrastructure (BrainCommon) to execute complex, context-aware decision-making.

The brain relies on the inventory component to track carried items and make stealing/chest-looting decisions, and uses FindEntity to locate valid targets within perception distance.

Dependencies & Tags

• Components used: inventory, container, inventoryitem
• Tags used for filtering targets:
  • For stealing: Must have tag "_inventoryitem", must not have tags "INLIMBO", "catchable", "fire", "irreplaceable", "heavy", "prey", "bird", "outofreach", "_container".
  • For chest looting: Must have tags "structure", "_container", "HAMMER_workable".

Properties

Property	Type	Default Value	Description
mytarget	Entity	nil	The current target entity Krampus is following or avoiding. Used primarily for player tracking.
greed	Number	Random (2–5)	The number of items Krampus must collect before departing. Initialized once on construction.
listenerfunc	Function	nil	Callback used to clear mytarget when the target entity is removed. Initialized lazily in SetTarget.

Main Functions

CanSteal(item)

• Description: Predicate function used to determine whether a given item is a valid target for Krampus to steal. The item must be pick-up-able, not near a player, and on valid ground.
• Parameters:
  • item (Entity): The candidate item entity.
• Returns:
  • true if Krampus can steal the item, otherwise false.

StealAction(inst)

• Description: Returns a buffered steal action (pickup) if Krampus's inventory is not full and a valid item exists within sight range. Otherwise, returns nil.
• Parameters:
  • inst (Entity): The Krampus entity instance.
• Returns:
  • BufferedAction instance if a target exists, otherwise nil.

CanHammer(item)

• Description: Predicate function to determine if a given entity is a valid treasure chest that Krampus can open. Must be a treasure chest, contain items, not be near a player, and be on valid ground.
• Parameters:
  • item (Entity): The candidate chest entity.
• Returns:
  • true if the chest is valid for looting, otherwise false.

EmptyChest(inst)

• Description: Returns a buffered hammer action to open a treasure chest if Krampus's inventory is not full and a valid chest is found. Otherwise, returns nil.
• Parameters:
  • inst (Entity): The Krampus entity instance.
• Returns:
  • BufferedAction instance if a chest is found, otherwise nil.

KrampusBrain:SetTarget(target)

• Description: Updates the current tracking target (typically a player). Manages removal and re-addition of the onremove event callback for proper cleanup when the target leaves the world. Prevents duplicate assignments.
• Parameters:
  • target (Entity or nil): The entity to track, or nil to clear the target.
• Returns:
  • nil

KrampusBrain:OnStop()

• Description: Called when the behavior tree stops. Clears the current tracking target.
• Parameters: None
• Returns: nil

KrampusBrain:OnStart()

• Description: Called when the behavior tree starts. Initializes the brain: sets initial tracking target to the player that spawned Krampus (spawnedforplayer), and constructs the behavior tree's root node.
• Parameters: None
• Returns: nil

Events & Listeners

• Listens to:
  • "onremove": Registered on the current mytarget entity to clear the reference when the target is removed from the world.
• Pushes: None (this brain does not directly fire custom events).