Overrides

Overview

Entity attributes have four data points that can be override using json files; see the following:

• Minimum Value minValue: the minimum value that this attribute’s instance is clamped to.
• Maximum Value maxValue: the maixmum value that this attribute’s instance is clamped to.
• Fallback Value defaultValue: the value that, should something go wrong, this attribute’s instance defers to (this almost never has any actual impact in-game, other than setting initial values if they are not otherwise provided).
• Increment Value incrementValue: used when calculating the diminishing returns of DIMINISHING attributes. Should be set to 0.0 otherwise.
• Translation Key translationKey: the key that gets the display name of the attribute.
• Stacking Behaviour stackingBehaviour: determines how different sources of this attribute’s value add together (either FLAT or DIMINISHING).’

1. Example 1

Minecraft’s armor attribute has the following:

• Default Value is 0.0.
• Minimum Value is 0.0.
• Maximum Value is 30.0.
• Increment Value is 0.0.
• Translation Key is attribute.name.generic.armor.

Say we want to change the maximum armor value to 100.0. We need to know the attribute’s registry key, which is comprised of a namespace and a path. In this case, the registry key is minecraft:generic.armor. In the directory data/minecraft/attributes/overrides we create the file generic.armor.json. Note how the registry key’s namespace matches our directory’s namespace, and the registry key’s path matches our file name.

We add the following to generic.armor.json:

{
    "defaultValue": 0.0,
    "minValue": 0.0,
    "maxValue": 100.0,
    "incrementValue": 0.0,
    "translationKey": "attribute.name.generic.armor",
    "stackingBehaviour": "FLAT"
}

That’s it. By using a datapack containing data/minecraft/attributes/overrides/generic.armor.json, the maximum value for armor is 100.

2. Example 2

Similarly to example 1, the same methodology can be used to create entirely new attributes. Say we have a mod with modid examplemod, and we want to add the attribute max_mana. We create the directory data/examplemod/attributes/overrides/ and create the file max_mana.json. Inside the json file add the following:

{
    "defaultValue": 0.0,
    "minValue": 0.0,
    "maxValue": 1000.0,
    "incrementValue": 0.0,
    "translationKey": "examplemod.attribute.name.max_mana",
    "stackingBehaviour": "FLAT"
}

We now have an attribute registered to the game. In our language file we can add the translation key entry like so:

"examplemod.attribute.name.max_mana": "Max Mana"

Although our attribute is registered to the game, it won’t be present on any living entity yet. The next step is to attach it to an entity’s attribute container - see Entity Types.

3. Example 3

The previous examples showed FLAT type attributes - here we see how vanilla Minecraft’s own Knockback Resistance attribute might be modified to be a DIMINISHING type:

{
    "defaultValue": 0.0,
    "minValue": 0.0,
    "maxValue": 1.0,
    "incrementValue": 0.01,
    "translationKey": "attribute.name.generic.knockback_resistance",
    "stackingBehaviour": "DIMINISHING"
}

This file would be named generic.knocback_resistance.json and be located in data/minecraft/attributes/overrides/.