
Mass
Weight and encumbrance plugin for Paper 1.21.11. Items have recipe-based weights (1 diamond = 1 kg), penalties scale from slowing to no-sprint to no-jump…
⬇ Download on ModrinthMass
Minecraft should care what you are carrying.
Mass gives every item a weight. Carry too much and you slow down, lose sprint, lose jump, sink in water, and make horses regret meeting you.
What it does
- Tracks weight across armor, hotbar, inventory, and offhand
- Slows movement as your load goes up
- Disables sprint and jump at higher weight tiers
- Makes heavy players sink in water
- Slows horses and counts chest cargo on horse-type mounts
- Blocks elytra when you are over the limit
- Adds the
Lighteningenchantment to make armor lighter
A diamond chestplate weighs 8 kg. Full diamond is enough to matter. Full netherite is a life choice.
Install
- Use Paper
1.21.11+ - Drop the jar into
plugins/ - Start the server once
- Edit
plugins/Mass/config.ymlif you want different weights or penalty thresholds - Run
/mass reload
Commands
All commands use mass.admin.
/mass reload/mass info [player]/mass lore [player]/mass item set <kg>/mass item clear/mass give lightening [1-3]
Config
The config is where most of the real control lives.
You can change:
- item weights
- category defaults
- sprint and jump thresholds
- water sinking
- horse slowdown
- elytra limit
- enchantment settings
If you want the plugin to feel punishing, you can do that. If you want it lighter and more survival-friendly, you can do that too.
Build
mvn clean package
Output goes to target/Mass-1.2.jar.
Notes
- Stackable items do not get lore or extra item data that would break stacking
- The plugin uses
Lightening, notLightning. That is on purpose - If something feels off, check the config first. Most of the balance lives there
Discord
If you want updates, feedback, or bug reports, join the Discord:
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.21.11
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as Mass-1.2.jar — drop this file into the mods folder
- Download size: 52 KB
- Download link checked 12 Sept 2026 — working
These come from our own check of the pack file, not from the source page.