# Armor radiation resistance

Radiation resistance assigned to armor items.

File: `data/<namespace>/hbm/hazmat_protection/<path>.json`.

The registry loads with the world and syncs to clients. Each item belongs to one rule; overlapping selectors fail world startup. Replace the original resource ID to change a shipped assignment. Reopen singleplayer or restart the server after changing rules or their tags.

For players, worn armor resistances and installed [cladding](https://movblock.mov/ntm-next/26.3/wiki/hazards-and-radiation/equipment-protection.md) add together. Incoming radiation is multiplied by $10^{-\mathrm{total\_resistance}}$. Rad-X adds 0.2 to the total while active. A total of 1 passes $10\%$ of the incoming dose; 2 passes $1\%$. Exposure paths that bypass armor retain their full dose.

## Fields

| Field | Meaning and default | Range |
| - | - | - |
| `targets` | Item ID, `#namespace:tag`, or item-ID list. | |
| `resistance` | Additive radiation resistance exponent for a worn piece. | `[0, f64::MAX]` |

## Example:

Override `hbm:minecraft/iron_helmet` at `data/hbm/hbm/hazmat_protection/minecraft/iron_helmet.json`:

```json
{
  "targets": "minecraft:iron_helmet",
  "resistance": 0.25
}
```