Cato's Mob Drops Editor

Change what bosses and other creatures drop using a simple config file. Nothing changes until you add a rule.

Install

Install this mod, BepInExPack Valheim, and Jötunn on the dedicated server and on every player's client. The client needs the mod because Valheim may let a player's game handle a creature's death and drops.

Configure the server here:

BepInEx/config/catos.mobdropseditor.cfg

Edit the Overrides line under [Drops], then restart the server. Jötunn sends the server's setting to connecting clients. Players' local config edits do not activate drop rules in multiplayer.

Add a rule

Put one rule on each line. Use prefab IDs, not display names.

CreaturePrefab|Operation|ItemPrefab|Min|Max|ChancePercent|ScaleByLevel|OnePerPlayer

For example, make every Greydwarf drop one Black Metal in addition to its normal drops:

Greydwarf|Add|BlackMetal|1|1|100|false|false

The chance is a percentage from 0 to 100. The last two values control whether amount scales with creature level and whether one item is dropped per player.

Available operations

Add       Add an item; if that item is already in the table, replace its settings.
Edit      Change an item already in the creature's drop table.
Remove    Remove one item from the creature's drop table.
Replace   Clear the table and add this item. Follow with Add rules for more items.
Disabled  Remove every drop from that creature.

Examples:

# Change the existing Eikthyr trophy to always drop once.
Eikthyr|Edit|TrophyEikthyr|1|1|100|false|false

# Stop Greydwarves dropping Resin.
Greydwarf|Remove|Resin|1|1|0|false|false

# Make Bonemass drop nothing.
Bonemass|Disabled

# Replace The Elder's whole table with Elder Bark and its trophy.
TheElder|Replace|ElderBark|1|2|100|false|false
TheElder|Add|TrophyTheElder|1|1|100|false|false

For Disabled, write only the creature ID and Disabled, separated by |. Lines beginning with # are comments. Prefab IDs are not case-sensitive.

Find prefab IDs

After the game loads, the mod creates this reference on both server and client:

BepInEx/config/catos.mobdropseditor.item-prefabs.txt

It lists item IDs registered in that game session, including compatible modded items. Creature IDs are available in the Jötunn prefab list; vanilla item IDs are also listed in the Jötunn item list.

Troubleshooting

• Nothing changes: Check that the rule is in the dedicated server's config, both server and clients have this mod and Jötunn, and the server was restarted after editing.
• The log says a prefab was not found: Check the exact prefab ID against the generated item list or Jötunn lists. The creature must have a CharacterDrop component.
• You still see normal drops: Add preserves normal drops. Use Replace to replace the whole table or Disabled to remove every drop.

The server log is at BepInEx/LogOutput.log. Look for Loaded N drop rule(s) from server config. on the server and Loaded N drop rule(s) from server synchronization. on a connected client.

This prevents local config edits from changing multiplayer drops. It does not stop a modified game client from spawning items through unrelated cheats or mods.