Minecraft Data Types

These are data types defined by Minecraft that are used in Origins JSON files. Understanding them is useful for working with powers, actions, and conditions.

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Item Stack

An Item Stack is the JSON representation of one or more items. It contains the item ID, count, and optional data components (which replaced NBT in 1.20.5+).

Field	Type	Default	Description
id	Identifier	required	Item ID (e.g. minecraft:diamond_sword)
count	Integer	1	Number of items (1~64)
components	Object	optional	Data component map

warning

If you upgrade your pack from 1.20.4 or earlier, you must convert all item stacks to the new format. The old nbt field is no longer supported and must be replaced with components.

Example:

{
    "id": "minecraft:diamond_sword",
    "count": 1,
    "components": {
        "minecraft:enchantments": {
            "levels": {
                "minecraft:sharpness": 5
            }
        }
    }
}

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Damage Type

A Damage Type is referenced by its Identifier from the damage_type registry (data/<namespace>/damage_type/). When a field's type is DamageType, you provide the Identifier that points to a damage type definition.

Example:

"damage_type": "minecraft:in_wall"

Damage types are defined in data packs at data/<namespace>/damage_type/ and specify properties like whether the damage bypasses armor, counts as fire, etc. For a list of common damage type IDs, see Minecraft Wiki: Damage Type.

A Damage Type JSON definition:

Field	Type	Default	Description
message_id	String	required	Translation key for the death message
exhaustion	Float	0.0	Hunger exhaustion caused
scaling	String	when_caused_by_living_non_player	never, always, or when_caused_by_living_non_player
effects	String	hurt	hurt, thorns, drowning, burning, poking, or freezing
death_message_type	String	default	default, fall_variants, or intentional_game_design

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Equipment Slot Group

An Equipment Slot Group specifies which equipment slot(s) an item occupies. It can be a single slot or a group.

Valid values for EquipmentSlotGroup:

Value	Description
any	Any equipment slot
hand	Either hand (mainhand or offhand)
armor	Any armor slot
head	Head armor slot
chest	Chest armor slot
legs	Legs armor slot
feet	Feet armor slot
mainhand	Main hand only
offhand	Off-hand only
body	Body slot (horse armor, wolf armor, etc.)

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Text Component

A Text Component is Minecraft's rich text format used for messages, tooltips, and titles. It can be a plain string or a complex JSON object.

Simple string:

"message": "Hello World!"

Styled text:

{
    "text": "Hello",
    "color": "gold",
    "bold": true
}

Translatable text:

{
    "translate": "origins.gui.choose_origin.title",
    "fallback": "Choose your Origin"
}

For full documentation, see Minecraft Wiki: Raw JSON text format.

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note

In this mod, if you use a simple string where a Text Component is expected, it will be automatically converted to a Translatable Text Component with the string as the translation key.

For example, "message": "origins.gui.choose_origin.title" is equivalent to:

"message": {
    "translate": "origins.gui.choose_origin.title"
}

MobEffectInstance

A MobEffectInstance defines a status effect applied to an entity. Serialized using MobEffectInstance.CODEC (1.21+).

Field	Type	Default	Description
id	Identifier	required	Effect ID (e.g. minecraft:speed)
duration	Integer	required	Duration in ticks
amplifier	Integer	0	Effect level (0 = level I, 1 = level II, etc.)
ambient	Boolean	false	Whether particles are more transparent
show_particles	Boolean	true	Whether particles are visible
show_icon	Boolean	true	Whether the icon is displayed in the HUD
hidden_effect	MobEffectInstance	optional	Nested effect instance (for effects like Bad Omen that chain another effect)

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EffectEntry

An EffectEntry is a simplified status effect definition used in some power types (e.g., origins:stacking_status_effect). Unlike MobEffectInstance, it omits the duration and hidden_effect fields.

Field	Type	Default	Description
id	Identifier	required	Effect ID
amplifier	Integer	0	Effect amplifier
ambient	Boolean	false	Whether particles are transparent
show_particles	Boolean	true	Whether to show particles
show_icon	Boolean	true	Whether to show the effect icon
id	Identifier	required	Effect ID
amplifier	Integer	0	Effect amplifier
ambient	Boolean	false	Whether the effect is ambient
show_particles	Boolean	true	Whether to show particles
show_icon	Boolean	true	Whether to show the icon