Weight System
by Starlinn
Weight System gives items, blocks and decorations a weight, so a player's carrying capacity limits what can be held and moved in the world.
What it does
Weight System adds weight attributes to items, blocks and decorations, and sets a player's maximum carrying capacity, which starts at 100. Recursive backpack calculations count the contents of backpacks as well, so items stored inside a container add to the total. A backpack with a higher tier can reduce the weight of the items it holds, and a conversion ratio controls how much of that weight is removed.
When the carried weight is greater than the player's capacity, a movement speed penalty applies, and the multiplier comes from a penalty rule. Rules can be added, removed or reset to the defaults, so a server can decide how heavy loads slow a player down. A configurable color HUD shows the current load, and pressing H opens its settings. The mod is a Forge mod for Minecraft 1.20.1 and runs on client and server, so both the server and every player need it. It is released under All rights reserved and is not open source, though its source code is public.
Key features
Item and block weights
Items, blocks and decorations carry weight attributes, and the weight of each is set in the mod's configuration.
Recursive backpack weight
Backpack contents are counted in the total, and higher-tier backpacks reduce the weight of the items inside them.
Movement speed penalty
Loads heavier than the carrying capacity slow the player, and penalty rules can be added, removed or reset.
Color HUD and commands
A configurable HUD shows the current load, opened with H, and commands change the capacity, conversion ratio and weights.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Survival pacing
Heavy loot and building materials slow travel, which makes inventory choices matter during exploration.
Server rules
Server owners can change the carrying capacity, penalty rules and weights to suit their own balance.
Who it’s for: Players who want inventory limits in survival or adventure play, and server owners who need to tune how heavy loads affect movement.
How it compares
SlotZero is a Forge mod for 1.20.1 that runs on client and server and is released under All rights reserved, so it is not open source. ArmorWeight covers 1.20.1 – 1.20.6, is released under the MIT License and also runs on client and server. Good Backpacks is released under the MIT License, is a Forge mod for 1.20.1 and needs both sides.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Weight System | Forge | 1.20.1 | Client and server | 2026-02-26 |
| SlotZero | Forge | 1.20.1 | Client and server | 2026-06-13 |
| ArmorWeight | Forge | 1.20.1 – 1.20.6 | Client and server | 2025-08-24 |
| Good Backpacks | Forge | 1.20.1 | Client and server | 2026-02-15 |
Questions
Does Weight System need to be installed on both sides?
Which Minecraft version does Weight System support?
Can backpack contents change the weight total?
In the catalog
Weight System is one of 29,952 Game mechanics mods on ModsFinder, and one of 13,316 Game mechanics mods for Forge. 34,764 mods support Minecraft 1.20.1.
Similar mods
What the author says
Add movement speed penalty rule: When the weight percentage is greater than, the player's movement speed is multiplied by
Official listing
- Modrinth page
- modrinth.com/mod/weight-system
- Owner
- Starlinn
- Published
- 2026-02-24
- Updated on Modrinth
- 2026-02-26
- Facts verified
- 2026-10-15