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Mosslingbrain

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

Overview​

MosslingBrain is a behavior tree-based brain component that governs the autonomous actions of mossling entities in Don't Starve Together. It coordinates behaviors such as foraging for food, harvesting or stealing from crops/stewers/dryers, summoning guardians when threatened, and fleeing or returning to base. The brain prioritizes actions dynamically using priority nodes and responds to changing game states like combat engagement, inventory status, and presence of a herd or guardian. It relies heavily on components like combat, herdmember, inventory, eater, knownlocations, and others to make decisions.

Dependencies & Tags​

  • Components used:

    • combat: for target management and guard summoning triggers.
    • crop: to check if crops are ready for harvest (IsReadyForHarvest).
    • dryer: to check if drying racks are done (IsDone).
    • eater: to determine edible items and check CanEat on targets.
    • guardian: to check for active guardian and summoning conditions (HasGuardian, SummonsAtMax).
    • herd: via herdmember to access herd members and avoid duplicate task claims.
    • herdmember: to access the associated herd for guard summoning.
    • inventory: for self-feeding and checking if inventory is full (IsFull, FindItem).
    • inventoryitem: to verify items aren’t currently held (IsHeld).
    • knownlocations: to remember spawn point and locate herd base (RememberLocation, GetLocation).
    • pickable: to check if plants are harvestable (CanBePicked, caninteractwith, product).
    • stewer: to check if cook pots are ready (IsDone).

  • Tags:

    • "structure": added to BASE_TAGS and STEAL_TAGS (used internally for entity classification).
    • "FX", "NOCLICK", "DECOR", "INLIMBO", "outofreach": excluded via NO_TAGS during entity searches.
    • "busy", "wantstoeat": state tags checked in stategraph to influence behavior.

Properties​

PropertyTypeDefault ValueDescription
instEntitynil (passed to constructor)The entity instance the brain is attached to; used to access components and stategraph.

Note: The constructor uses Class(Brain, function(self, inst) ... end) pattern. No additional instance properties are initialized within the constructor itself; properties are either inherited from Brain or lazily accessed via self.inst.components.*.

Main Functions​

MosslingBrain:OnStart()​

  • Description: Initializes and assigns the behavior tree root node based on current and dynamic conditions. Constructs a priority-based behavior tree that evaluates conditions in order (panic triggers, home departure, attack mode, threat response, base-following).
  • Parameters: None.
  • Returns: nil.

MosslingBrain:OnInitializationComplete()​

  • Description: Records the mossling’s initial spawn position as "spawnpoint" in its knownlocations component for navigation reference.
  • Parameters: None.
  • Returns: nil.

GoHome(inst)​

  • Description: Utility function that returns a buffered GOHOME action if the mossling is configured to leave the herd (shouldGoAway) and has no active combat target.
  • Parameters:
    • inst (Entity): The mossling entity instance.
  • Returns: BufferedAction or nil.

TargetNotClaimed(inst, target)​

  • Description: Checks if another mossling in the same herd has already claimed the same target for harvesting, to prevent duplicate actions.
  • Parameters:
    • inst (Entity): The current mossling entity.
    • target (Entity): The potential target entity.
  • Returns: boolean — true if no other mossling has claimed the target, false otherwise.

EatFoodAction(inst)​

  • Description: Attempts to locate food for immediate consumption. Prioritizes food in the mossling’s own inventory. If not found, scans nearby entities for edible items (e.g., berries, carrots), ensuring they are matured, unheld, and unclaimed. Returns a PICKUP action to collect food if found.
  • Parameters:
    • inst (Entity): The mossling entity instance.
  • Returns: BufferedAction (for EAT or PICKUP) or nil.

StealFoodAction(inst)​

  • Description: Searches for structures (e.g., crop plots, stew pots, drying racks) ready for harvesting, then harvests or picks them to acquire food. Prioritizes items in this order: stewers > dryers > crops > pickable plants (e.g., berries, carrots, mushrooms). Avoids claimed targets.
  • Parameters:
    • inst (Entity): The mossling entity instance.
  • Returns: BufferedAction (for HARVEST or PICK) or nil.

SummonGuardian(inst)​

  • Description: Attempts to summon the herd’s guardian if the guardian is missing or not at summoning capacity (guardian == nil or summons < threshold), the mossling has a combat target, and is not busy.
  • Parameters:
    • inst (Entity): The mossling entity instance.
  • Returns: BufferedAction (for SUMMONGUARDIAN) or nil.

Events & Listeners​

The brain file itself does not register event listeners. However, it leverages the parent Brain class’s behavior tree execution, which internally interacts with the entity’s stategraph and event-driven systems (e.g., OnUpdate triggers). No explicit inst:ListenForEvent or inst:PushEvent calls are present in this file.