Moonspiderden

Based on game build 714014 | Last updated: 2026-03-06

Overview

moonspiderden is a prefabricated structure representing a mutating lunar spider mound. It functions as a dynamic boss arena element that regenerates over time, adjusts its aggression and spider capacity based on damage taken, and reacts to world events like quakes and daytime in caves. It relies heavily on the workable, childspawner, lootdropper, and sleeper components, and manages multiple spawn states and sound/animation behaviors depending on its health. The den is non-player controllable and triggers large-scale spider spawns when mined or interacted with.

Usage example

This component is instantiated automatically by the game via the moonspiderden prefab definition and is not meant for direct instantiation by modders. However, modders can interact with its public API:

-- Example of invoking a public method on an existing moonspiderden instance
local den = SpawnPrefab("moonspiderden")
if den ~= nil then
    -- Force all current and pending spiders to spawn immediately (e.g. in response to an event)
    den.components.childspawner:ReleaseAllChildren()
    -- Or use the den's own SummonChildren method
    den:PushEvent("startquake") -- triggers quaking behavior that wakes buried spiders
end

Dependencies & tags

Components used: workable, childspawner, lootdropper, inspectable, sleeper, inventory, knownlocations, burnable, fueled, hauntable, groundcreepentity, obstacle, physics, animstate, soundemitter, minimapentity, transform, network.

Tags: Adds spiderden. Does not add cavedweller (commented out in source).

Properties

Property	Type	Default Value	Description
_stage	number	LARGE (3)	Current growth stage (SMALL=1, MEDIUM=2, LARGE=3). Updated when work is done or regenerated.
_num_investigators	number	2 (stage-dependent)	Max number of spiders assigned to investigate a player's location.
_idle_task	task	nil	Periodic task responsible for idle twitch animations.
_regen_task	task	nil	Periodic task responsible for passive regeneration of work left.
_sleep_start_time	number	nil	Timestamp when entity entered sleep state; used to compute regen during sleep.

Main functions

set_stage(inst, workleft, regrow)

• Description: Determines and sets the den's current growth stage based on remaining work, adjusts child counts and emergency warrior limits accordingly, updates ground creep radius, and triggers stage-change animations and sounds if regrow is true. |
• Parameters: workleft (number) — current remaining work points; regrow (boolean) — if true, enables growth animations and regen-based sounds. |
• Returns: Nothing. Modifies inst._stage, childspawner capacities, and visual state. |

SpawnInvestigators(inst, data)

• Description: Spawns up to _num_investigators spiders outside the den, marks them with "investigate" location data, and triggers twitch animations. Used in response to "creepactivate" events. |
• Parameters: data (table, optional) — expected to contain target (an entity), used to record investigation position. |
• Returns: Nothing. May spawn new spiders and set "investigate" locations via knownlocations. |

SummonChildren(inst, data)

• Description: Forces all pending and currently allocated children to spawn immediately (ignoring spawn timers). Applies "spider_summoned_buff" debuff to newly spawned spiders. Used for event-triggered mass spawns. |
• Parameters: data (table, unused). |
• Returns: Nothing. Calls childspawner:ReleaseAllChildren() and applies debuffs. |

push_twitch_idle(inst, skip_anim_check)

• Description: Triggers random twitch animations and sound effects (cracking sounds) at timed intervals, typically when the den is above 50% health and not in a non-twitch animation. |
• Parameters: inst (EntityInst), skip_anim_check (boolean, optional) — if true, skips animation state checks. |
• Returns: Nothing. Schedules sounds and animation changes via DoTaskInTime. |

OnGoHome(inst, child)

• Description: Called when a spawned spider returns home. Drops any equipped hat item (head slot) before the spider goes home. |
• Parameters: inst (EntityInst - den), child (EntityInst - spider). |
• Returns: Nothing. Uses inventory:GetEquippedItem(EQUIPSLOTS.HEAD) and inventory:DropItem(). |

OnSpawnChild(inst, spider)

• Description: Callback invoked immediately after a spider is spawned. Instructs the spider to enter the "taunt" state. |
• Parameters: inst (EntityInst - den), spider (EntityInst - newly spawned spider). |
• Returns: Nothing. Sets spider stategraph state via spider.sg:GoToState("taunt"). |

StopSpawning(inst)

• Description: Stops spider spawning by calling childspawner:StopSpawning(). Triggered on entering a cave day. |
• Parameters: inst (EntityInst - den). |
• Returns: Nothing. Does nothing if childspawner is missing. |

StartSpawning(inst)

• Description: Starts spider spawning by calling childspawner:StartSpawning(). Triggered on exiting a cave day (e.g., back to surface or night). |
• Parameters: inst (EntityInst - den). |
• Returns: Nothing. Does nothing if childspawner is missing or in cave day. |

Events & listeners

• Listens to: creepactivate — triggers SpawnInvestigators.
• Listens to: startquake (via TheWorld.net) — triggers OnQuakeBegin, which wakes spiders and sets _quaking = true.
• Listens to: endquake (via TheWorld.net) — triggers OnQuakeEnd, which clears _quaking.
• Pushes: dropitem — fired internally when inventory drops items (via inventory:DropItem).
• Pushes: onwakeup — fired internally when sleeper wakes up (via sleeper:WakeUp).
• Pushes: entity_droploot — fired after loot is dropped.