Durability Decay

Every repair reduces an item’s usable durability. A thin red segment appears on the right side of the durability bar to show the lost portion. Mending does not cause decay by default.

The tooltip of a diamond sword that has been repaired several times

How It Works

Physical repairs cause small, permanent durability loss.
Red segment grows from the right as items decay more.
When the red segment reaches the limit, the item can’t be fully restored by physical means.
Mending is exempt by default. You can enable it per config.

Configuration

base Fixed decay added on every repair.
fraction Portion of the repaired amount that becomes decay.
max Maximum decay per operation
min Minimum decay per operation
mending_impacts_block
false = Mending does not add decay.
true = Mending also adds decay.

Defaults

base: 0
fraction: 0.25
max: 0.5
min: 0
mending_impacts_block: false

Notes

Per-item config supported
Works with item tags for batch tuning.

FAQ

Why is Mending exempt?
Physical repairs aren't going to be perfect, so they reduce integrity.

Can I disable decay for certain items?
Yes. Set their max to 0 or omit them from your rules and rely on defaults.

Example Config

{
  "default": {
    "base": 0,
    "fraction": 0.25,
    "max": 0.5,
    "min": 0,
    "mending_impacts_block": false
  },
  "items": {
    "minecraft:diamond_sword": {
      "base": 0.02,
      "fraction": 0.3,
      "max": 3,
      "min": 0,
      "mending_impacts_block": false
    }
  }
}