Configurable Mob Potion Effects (Legacy Fabric)
Imagine a world where every creeper leaves you with mining fatigue, every skeleton poisons you on hit, and every slime zooms around at breakneck speed. With Configurable Mob Potion Effects (Legacy Fabric), that world is yours to design. This server-side mod hands the reins to administrators, allowing them to assign permanent potion effects to any mob and define exactly what happens when a mob damages a player or another entity. It is completely configurable, works with all modded entities and potion effects, and does nothing by default—so you have total control from the very first line of text.
What Makes This Mod Special
Unlike many gameplay tweaks that force a specific vision, Configurable Mob Potion Effects (Legacy Fabric) is a blank canvas. It ships with no active changes. Instead, it generates two clean configuration files that list every entity and every potion effect available in your game, including those added by other mods. You simply find the right line, set a level and duration, and reload. The mod then applies those rules globally on the server, no client installation required. This makes it perfect for modded survival servers, custom adventure maps, or anyone who wants to spice up vanilla mob behavior without writing a single line of code.
How It Works
The mod operates through two text-based config files, both located in the ./config/configurablemobpotioneffects/ folder. On first load, it scans your entire modded environment and populates these files with every known entity and potion effect, all set to level 0 (disabled). You edit the values, save, and either restart the game or run a simple command to apply the changes instantly. Because it hooks into the Fabric API and the required library mod Collective (Fabric), it remains lightweight and compatible with a wide range of other mods.
Configuration Files in Detail
Permanent Effects: permanenteffects.txt
This file controls which mobs carry a potion effect at all times. Each mob has its own section, and within that section you can set the level for any potion effect. For example, to make all slimes permanently fast, you would locate the slime entry, find the speed effect, and change its level from 0 to 50. The effect then applies to every slime that spawns, without any duration limit. You can stack multiple effects on a single mob, creating truly bizarre combinations like a regenerating, fire-resistant chicken.
On-Damage Effects: ondamageeffects.txt
This file defines what happens when a mob attacks a target. For each mob, you can set the level and duration of any potion effect that will be applied to the victim upon taking damage. Want endermites to give levitation 10 for one second? Find the endermite section, set levitation level to 10 and duration to 20 ticks (1 second), and watch players float helplessly after a bite. The duration is measured in ticks, so you have precise control over how long the effect lingers.
Commands at Your Fingertips
After editing the config files, you don't always need a full server restart. The mod provides a single command: /cmpe reload. This reloads all manual changes from the config files on the fly, making it easy to test and tweak settings without interrupting gameplay. It is a simple yet powerful tool for iterative design.
Practical Examples to Get You Started
Let's walk through a few scenarios to see the mod in action. First, a classic: a super-fast slime. Open permanenteffects.txt, find the slime section, and set the speed level to 50. Save, run /cmpe reload, and every slime in the world will now bounce around at incredible velocity.
Next, make zombies both faster and poisonous. In permanenteffects.txt, give the zombie a speed level of 5. Then in ondamageeffects.txt, set the zombie's poison level to 2 with a duration of 100 ticks (5 seconds). Now zombies are not only quicker but also inflict a lingering poison on anyone they hit. The combination turns a mundane mob into a serious threat.
For a more whimsical twist, try giving bats a permanent invisibility effect—they are already hard to see, but now they truly vanish. Or make iron golems apply slowness to hostile mobs they strike, turning them into crowd-control guardians. The possibilities are limited only by the potion effects available in your modpack.
Installation and Compatibility
To use Configurable Mob Potion Effects (Legacy Fabric) for Minecraft, you need a Fabric loader environment running version 1.16 or 1.17. This legacy page specifically serves those older versions; newer Fabric releases (1.18+) and Forge editions are available on the main project page. The mod requires Fabric API and the Collective (Fabric) library. Simply place both JARs in your server's mods folder, start the server once to generate the config files, and you are ready to customize.
If you are wondering how to install the mod quickly, the process is straightforward: download Configurable Mob Potion Effects (Legacy Fabric) from CurseForge, along with its dependencies, and drop them into the mods directory. For those who prefer a streamlined experience, the foxygame.net launcher offers a one-click install option that automatically fetches the correct version of Configurable Mob Potion Effects (Legacy Fabric) and all required libraries, ensuring perfect compatibility with your Fabric 1.16 or 1.17 setup.
Why Server Owners Love It
Because the mod is entirely server-side, players can join with a vanilla client and still experience all the custom mob behaviors. This eliminates the need for everyone to install the mod, making it ideal for public servers. The config files are human-readable and easy to share, so you can quickly replicate your favorite setups across multiple worlds. And since it respects all modded entities and effects, you can integrate it seamlessly into any modpack without conflicts.
Taking Full Control
Configurable Mob Potion Effects (Legacy Fabric) puts the power of potion manipulation directly into your hands. Whether you want to create a punishing hardcore experience, a hilarious chaos server, or a carefully balanced adventure map, this mod gives you the tools to shape mob behavior exactly as you envision. Start with a single change, reload, and watch your world transform—one potion effect at a time.