Introduction to Enchantment Patches

The JSON files for the defaulted:enchantment_patches data should be put in data/<namespace>/defaulted/enchantment_patches/<path>.json.

For information on how patches are applied, see ordering information.

Creating a File

For this tutorial, let's presume that you wish to add the minecraft:post_attack component with effect minecraft:ignite to some enchantments which do not already have it.

Let's start off with our JSON file, say we want it to be called custom:make_cause_ignite.

To do this, let's start off by creating a JSON file in data/custom/defaulted/enchantment_patches/make_cause_ignite.json

IMPORTANT

Patches can include any enchantment effect component type, as long as it is registered. This INCLUDES modded enchantment effect component types.

Similarly, any enchantment can be patched, INCLUDING modded ones!

Adding Components

Next, in the JSON, let us create a JSON Object as our root, and define the patch:

{
  "patch": {}
}

IMPORTANT

The patch object is a Data Component Patch, as you would create inside of a recipe if you wanted to produce an enchantment with custom components. Syntax is thus the same as a recipe.

Following that, let's fill out the patch with our edited post_attack component:

{
  "patch": {
    "minecraft:post_attack": [
      {
        "affected": "victim",
        "effect": {
          "type": "minecraft:ignite",
          "duration": {
            "type": "minecraft:linear",
            "base": 1.0,
            "per_level_above_first": 0.25
          }
        },
        "enchanted": "attacker",
        "requirements": {
          "condition": "minecraft:damage_source_properties",
          "predicate": {
            "is_direct": true
          }
        }
      }
    ]
  }
}

Now, that looks good! Except, we have a problem...

This component patch will apply to every single enchantment that exists.

That is fine if you want to make a global change, but remember that in this example we wanted to only apply it to certain enchantments.

From this point, I will introduce the next element: The elements field, which defines a list of either registered, existing enchantments or tags prefixed with # to apply the patch to.

Details

If the elements field is empty or absent, the patch is global, or rather, applies to every enchantment that exists.

Any enchantment which is either in the enchantments directly included in elements or is in a tag included in elements will be patched.

For our example, let's say we want every damage enchantment to get this post attack component:

{
  "elements": [
    "#minecraft:exclusive_set/damage"
  ],
  "patch": {
    "minecraft:post_attack": [
      {
        "affected": "victim",
        "effect": {
          "type": "minecraft:ignite",
          "duration": {
            "type": "minecraft:linear",
            "base": 1.0,
            "per_level_above_first": 0.25
          }
        },
        "enchanted": "attacker",
        "requirements": {
          "condition": "minecraft:damage_source_properties",
          "predicate": {
            "is_direct": true
          }
        }
      }
    ]
  }
}

NOTE

This could also be done by manually listing off every damage enchantment, however best practice in this case is to use the tag since it will include modded damage enchantments by default.

Now, we are almost done. However, just to not implant false ideas, let's say we also wanted Protection to cause this post attack effect.

The addition to make this occur, is as follows:

{
  "elements": [
    "#minecraft:exclusive_set/damage",
    "minecraft:protection"
  ],
  "patch": {
    "minecraft:post_attack": [
      {
        "affected": "victim",
        "effect": {
          "type": "minecraft:ignite",
          "duration": {
            "type": "minecraft:linear",
            "base": 1.0,
            "per_level_above_first": 0.25
          }
        },
        "enchanted": "attacker",
        "requirements": {
          "condition": "minecraft:damage_source_properties",
          "predicate": {
            "is_direct": true
          }
        }
      }
    ]
  }
}

Removing Components

Now, what if you wanted to, say, remove the damage from, say, all damage enchantments?

Ignoring the frivolity of such an idea, here is how you would do that:

{
  "elements": [
    "#minecraft:exclusive_set/damage"
  ],
  "patch": {
    "!minecraft:damage": {}
  }
}

NOTE

Just as removing a component from an item stack in a patch, to remove a default component here, you just append a ! in front of the component name.

Enchantment Field Overrides

Enchantment patches modify more than just their enchantment effect components, as they represent overrides for the enchantment as a whole. As such, they have a few more fields, largely corresponding to equivalents for enchantments themselves.

NOTE

For the purposes of these fields, a "homogenous list" refers to a list that can either be a single tag of that type, or a list of that type.

IMPORTANT

NONE of the fields here must be defined for the enchantment patch to work. If they are present, you are expected to be using them with intent.

1. description: A component to override the original enchantment's description with.
2. supported_items: A homogeneous list of items to override the original enchantment's supported_items with.
3. primary_items: A homogeneous list of items to override the original enchantment's primary_items with.
4. weight: A Value Provider to modify the original enchantment's weight (provided as variable "input").
5. max_level: A Value Provider to modify the original enchantment's max_level (provided as variable "input").
6. min_cost: A cost to modify the original enchantment's min_cost.
7. max_cost: A cost to modify the original enchantment's max_cost.
8. anvil_cost: A Value Provider to modify the original enchantment's anvil_cost (provided as variable "input").
9. slots: A list of slots to override the original enchantment's slots with.
10. added_slots: A list of slots to add to the original enchantment's slots if slots is not present.
11. removed_slots: A list of slots to remove from the original enchantment's slots if slots is not present.
12. exclusive_set: A homogeneous list of enchantments to override the original enchantment's exclusive_set with.
13. patch: A data component patch to apply to the original enchantment's effects. (See here for usage).

Cost Override

For replacing the costs, this is used. The fields are as follows:

1. base: A Value Provider to modify the original cost's base (provided as variable "input").
2. per_level_above_first: A Value Provider to modify the original cost's per_level_above_first (provided as variable "input").