Merm Tool

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

Overview

merm_tool defines a reusable weapon/tool entity specifically for Merm NPCs. It combines functionality from the weapon, tool, equippable, and finiteuses components to provide context-sensitive damage, tool action support (CHOP, MINE, DIG, TILL), and consumable durability. The tool's damage is dynamically computed based on whether the wielder is a Merm NPC. It is instantiated for both standard and upgraded variants via a factory function.

Usage example

-- Standard usage: add the tool to an NPC entity and equip it
local inst = CreateEntity()
inst:AddPrefabOverride("merm_tool")
inst:AddTag("merm_npc")
inst.components.inventory:Equip(inst.components.inventory:GetSlot("hands"), inst)
-- Tool will show 'ARM_carry', apply weapon damage, and consume uses on tool actions

Dependencies & tags

Components used: combat, equippable, finiteuses, tool, weapon, inventoryitem, farmtiller, inspectable, soundemitter, transform, animstate, network Tags: merm_tool, tool, weapon, merm_npc (used as a restriction tag), usesdepleted (added when durability reaches zero)

Properties

Property	Type	Default Value	Description
non_merm_damage	number	inherited from TUNING.MERM_TOOL.DAMAGE	Base damage value assigned on creation, used unless wielder is a non-Merm NPC (damage is capped to combat.defaultdamage).
_build	string	e.g., "mermtool"	Symbol build name used for anim state overrides.
_swapsymbol	string	e.g., "swap_mermtool"	Symbol name used for anim state overrides.

Main functions

OnEquip(inst, owner)

• Description: Handles equipping the tool: applies skin overrides if present, anim state changes (ARM_carry shown, ARM_normal hidden), and signals skin events.
• Parameters:
  inst (Entity) — the tool instance being equipped.
  owner (Entity) — the entity equipping the tool.
• Returns: Nothing.
• Error states: No explicit error handling; relies on owner.AnimState existing.

OnUnequip(inst, owner)

• Description: Handles unequipping the tool: signals skin removal if applicable and restores arm animation state (ARM_carry hidden, ARM_normal shown).
• Parameters:
  inst (Entity) — the tool instance being unequipped.
  owner (Entity) — the entity unequipping the tool.
• Returns: Nothing.

getDamage(inst, attacker, target)

• Description: Computes the effective damage dealt by the tool. For Merm NPC attackers (HasTag("merm_npc")), damage is the greater of non_merm_damage or the attacker's default combat damage. For non-Merm attackers, it simply returns non_merm_damage.
• Parameters:
  inst (Entity) — the tool instance.
  attacker (Entity) — the entity performing the attack.
  target (Entity) — the entity being attacked (unused in logic).
• Returns: number — effective damage value.

CreateMermTool(data)

• Description: Factory function that builds and configures a merm_tool or merm_tool_upgraded prefab instance. Sets up components, animations, sound, and durability tuning.
• Parameters:
  data (table) — configuration with keys: prefab (string), bank (string), build (string), tuning (string), assets (table of Asset definitions), and optional skindata.
• Returns: Prefab — fully defined prefab object ready for world instantiation.
• Error states: None. Relies on TUNING[data.tuning] being defined.

Events & listeners

• Listens to: None (no inst:ListenForEvent calls).
• Pushes:
  • "equipskinneditem" — sent to the owner when equipping a skinned tool.
  • "unequipskinneditem" — sent to the owner when unequipping a skinned tool.
  • "percentusedchange" — sent by finiteuses when durability changes (e.g., on use or deactivation).
  • "usesdepleted" — tag added by finiteuses when durability reaches zero.
  • "toolfinished" — sent when finiteuses.onfinished (i.e., inst.Remove) is called.