{{For|predicates inside models|Tutorials/Models#Item predicates}}
{{Exclusive|java}}
'''Predicates''' are JSON structures found in multiple different locations within data packs. They are invoked with various means to check conditions within the world. They return a ''pass'' or ''fail'' result to the invoker, who acts differently based on this result.
'''Predicate files''' are standalone data pack files that contain one or more predicates. Predicates can also be defined in other ways.
This article describes how predicates are defined and invoked, and also describes the JSON structure of a predicate.
== Definition ==
A predicate file is defined with the [[JSON]] format.
Predicate files are part of the data pack directory structure, highlighted below:
{{Data pack directory|predicate|.json}}
The root element of a predicate file can be either an {{nbt|compound|object}} following the predicate structure below, or an {{nbt|list|array}} containing multiple predicates.
== Usage ==
Predicates and predicate files can be invoked in several different manners from other data pack files:
=== Commands ===
[[Commands]] or [[Function (Java Edition)|functions]] can invoke predicate files in two ways:
* [[Target selectors]]: The selector argument predicate= checks predicate files as a filter for entity selection. The predicate file is invoked once per entity that needs filtering, each time being at the entity's location.
* {{Cmd|execute}}: A subcommand, /execute if predicate, can invoke a predicate file to either return a result or to decide whether to continue with a subcommand chain. The predicate file is invoked once at the current contextual position of execution.
=== Other predicates ===
The condition type minecraft:reference invokes a predicate file and returns the result to the invoker.
=== Presence in other files ===
In addition to predicate files, predicates themselves are used in other locations within other data pack files such as [[Advancement/JSON format|advancements]] and [[Loot table|loot tables]].
== JSON format ==
This section describes the JSON format of a predicate.
* {{nbt|compound}}: The root element of the predicate.
** {{nbt|string|condition}}: The [[resource location]] of the condition type to check.
** Other parts of the predicate, specified below.
The possible values for {{nbt|string|condition}} and associated extra contents:
* '''all_of'''—Evaluates a list of predicates and passes if all of them pass. Invokable from any context.
** {{nbt|list|terms}}: The list of predicates to evaluate. A predicate within this array must be a {{nbt|compound|object}}.
*** {{nbt|compound}} A predicate, following this structure recursively.
* '''any_of'''—Evaluates a list of predicates and passes if any one of them passes. Invokable from any context.
** {{nbt|list|terms}}: The list of predicates to evaluate. A predicate within this array must be a {{nbt|compound|object}}.
*** {{nbt|compound}} A predicate, following this structure recursively.
* '''block_state_property'''—Checks the mined block and its [[block states]]. Requires block state provided by [[loot context]], and always fails if not provided.
** {{nbt|string|block}}: A block ID. The test fails if the block doesn't match.
** {{nbt|compound|properties}}: ''(Optional)'' A map of block state names to values. Errors if the block doesn't have these properties.
*** {{nbt|string|''name''}}: A block state and a exact value. The value is a string.
*** {{nbt|compound|''name''}}: A block state name and a ranged value to match.
**** {{nbt|string|min}}: The min value.
**** {{nbt|string|max}}: The max value.
* '''damage_source_properties'''—Checks properties of the damage source. Requires origin and damage source provided by [[loot context]], and always fails if not provided.
** {{nbt|compound|predicate}}: Predicate applied to the damage source.
*** {{Nbt_inherit/conditions/damage_type|indent=***}}
* '''enchantment_active_check'''—Checks if the enchantment has been active. Requires enchantment active status provided by [[loot context]], and always fails if not provided. It is therefore only usable from the {{cd|enchanted_location}} loot context.
** {{nbt|boolean|active}}: Whether to check for an active ({{cd|true}}) or inactive ({{cd|false}}) enchantment.
* '''entity_properties'''—Checks properties of an entity. Invokable from any context.
** {{nbt|string|entity}}: The entity to check. Specifies an entity from [[loot context]]. Can be {{cd|this}}, {{cd|attacker}}, {{cd|direct_attacker}}, or {{cd|attacking_player}}.
** {{nbt|compound|predicate}}: Predicate applied to entity, uses same structure as advancements.
*** {{nbt inherit/conditions/entity|indent=***}}
* '''entity_scores'''—Checks the [[scoreboard]] scores of an entity. Requires the specified entity provided by [[loot context]], and always fails if not provided.
** {{nbt|string|entity}}: The entity to check. Specifies an entity from [[loot context]]. Can be {{cd|this}}, {{cd|attacker}}, {{cd|direct_attacker}}, or {{cd|attacking_player}}.
** {{nbt|compound|scores}}: Scores to check. All specified scores must pass for the condition to pass.
*** {{nbt|compound|A score}}: Key name is the objective while the value specifies a range of score values required for the condition to pass.
**** {{nbt|int}}{{nbt|compound|min}}: A [[Loot table#Number provider|number provider]]. Minimum score. Optional.
**** {{nbt|int}}{{nbt|compound|max}}: A [[Loot table#Number provider|number provider]]. Maximum score. Optional.
*** {{nbt|int|A score}}: Shorthand version of the other syntax above, to check the score against a single number only. Key name is the objective while the value is the required score.
* '''inverted'''—Inverts another predicate condition. Invokable from any context.
** {{nbt|compound|term}}: The condition to be negated, following the same structure as outlined here, recursively.
* '''killed_by_player'''—Checks if there is a {{cd|attacking_player}} entity provided by [[loot context]]. Requires {{cd|attacking_player}} entity provided by [[loot context]], and always fails if not provided.
* '''location_check'''—Checks the current location against location criteria. Requires origin provided by [[loot context]], and always fails if not provided.
** {{nbt|int|offsetX}}: An optional x offset to the location.
** {{nbt|int|offsetY}}: An optional y offset to the location.
** {{nbt|int|offsetZ}}: An optional z offset to the location.
** {{nbt|compound|predicate}}: Predicate applied to location, uses same structure as advancements.
*** {{nbt inherit/conditions/location|indent=***}}
* '''match_tool'''—Checks tool used to mine the block. Requires tool provided by [[loot context]], and always fails if not provided.
** {{nbt|compound|predicate}}: Predicate applied to item, uses same structure as advancements.
*** {{nbt inherit/conditions/item|indent=***}}
* '''random_chance'''—Generates a random number between 0.0 and 1.0, and checks if it is less than a specified value. Invokable from any context.
** {{nbt|float}}{{nbt|compound|chance}}: A [[Loot table#Number provider|number provider]]. Success rate as a number 0.0–1.0.
* '''random_chance_with_enchanted_bonus'''—Generates a random number between 0.0 and 1.0, and checks if it is less than the value determined using the level of a given enchantment. Requires attacker entity provided by [[loot context]], and if not provided, the enchantment level is regarded as 0.
** {{nbt|float|unenchanted_chance}}: The success rate to use when the enchantment is not present; 0.0–1.0.
** {{nbt|float}}{{nbt|compound|enchanted_chance}}: [[level-based value]]. The success rate based on the level when then enchantment is present; 0.0–1.0.
** {{nbt|string|enchantment}}: {{json ref|enchantment|custom enchantment}}. The enchantment whose level to use for the chance calculation. If the enchantment is not present, uses {{cd|0}} as level.
* '''reference'''—Invokes a predicate file and returns its result. Invokable from any context.
** {{nbt|string|name}}: The [[resource location]] of the predicate to invoke. A cyclic reference causes a parsing failure.
* '''survives_explosion'''—Returns success with {{cd|1 ÷ explosion radius}} probability. Requires explosion radius provided by [[loot context]], and always success if not provided.
* '''table_bonus'''—Passes with probability picked from a list, indexed by enchantment power. Requires tool provided by [[loot context]]. If not provided, the enchantment level is regarded as 0.
** {{nbt|string|enchantment}}: [[Resource location]] of enchantment.
** {{nbt|list|chances}}: List of probabilities for enchantment power, indexed from 0.
* '''time_check'''—Compares the current day time (or rather, 24000 * day count + day time) against given values. Invokable from any context.
** {{nbt|compound|value}}: The time to compare the day time against.
*** {{nbt|int}}{{nbt|compound|min}}: A [[Loot table#Number provider|number provider]]. The minimum value.
*** {{nbt|int}}{{nbt|compound|max}}: A [[Loot table#Number provider|number provider]]. The maximum value.
** {{nbt|int|value}}: Shorthand version of {{nbt|compound|value}} above, used to check for a single value only. Number providers cannot be used in this shorthand form.
** {{nbt|int|period}}: If present, the day time is first reduced modulo the given number before being checked against {{nbt|compound}}{{nbt|int|value}}. For example, setting this to 24000 causes the checked time to be equal to the current daytime.
* '''value_check'''—Compares a number against another number or range of numbers. Invokable from any context.
** {{nbt|int}}{{nbt|compound|value}}: A [[Loot table#Number provider|number provider]]. The number to test.
** {{nbt|compound|range}}: The range of numbers to compare {{nbt|int}}{{nbt|compound|value}} against.
*** {{nbt|int}}{{nbt|compound|min}}: A [[Loot table#Number provider|number provider]]. The minimum value.
*** {{nbt|int}}{{nbt|compound|max}}: A [[Loot table#Number provider|number provider]]. The maximum value.
** {{nbt|int|range}}: Shorthand version of {{nbt|compound|range}} above, used to compare {{nbt|int}}{{nbt|compound|value}} against a single number only. Number providers cannot be used in this shorthand form.
* '''weather_check'''—Checks the current game weather. Invokable from any context.
** {{nbt|boolean|raining}}: If true, the condition passes only if it is raining or thundering.
** {{nbt|boolean|thundering}}: If true, the condition passes only if it is thundering.
== History ==
{{HistoryTable
|{{HistoryLine|java}}
|{{HistoryLine||1.15|dev=19w38a|Added predicates to data packs.}}
|{{HistoryLine||1.16|dev=20w12a|Added fishing_hook sub-predicate into entity predicate to check properties of the fishing hook.}}
|{{HistoryLine||1.19|dev=22w14a|{{cd|player|fishing_hook|lightning_bolt|catType|d=and}} fields have been replaced with {{cd|type_specific}}. {{cd|type_specific}} has field {{cd|type}} (one of {{cd|player|fishing_hook|lightning_bolt|cat|d=or}}) and same sub-fields as removed fields.}}
|{{HistoryLine||1.19.3|dev=23w06a|Removed {{cd|d=and|is_projectile|is_explosion|bypasses_armor|bypasses_invulnerability|bypasses_magic|is_fire|is_magic|is_lightning}} fields from {{cd|damage_source_properties}}.|A new {{cd|tags}} array has been added to {{cd|damage_source_properties}}. Each entry has two fields:
* {{cd|id}}: The ID of a damage type tag.
* {{cd|expected}}: Whether the damage is expected to have or not have the tag for the predicate to match.}}
|{{HistoryLine||1.20|dev=23w18a|Condition {{cd|alternative}} has been renamed to {{cd|any_of}}.|Added new condition {{cd|all_of}} that passes only when all sub-conditions pass, with the same syntax as {{cd|any_of}}.}}
|{{HistoryLine||1.20.5|dev=24w09a|Item predicate format has been updated:
*{{cd|tag}} field has been removed.
*{{cd|items}} field now supports a single entry, hash-prefixed item tag, or list of items.
*{{cd|potion}} renamed to {{cd|potions}}, and supports a single entry, hash-prefixed potion tag, or list of potions.
*{{cd|nbt}} predicate has been renamed to {{cd|custom_data}} and now matches {{cd|minecraft:custom_data}} component.
*A new optional {{cd|components}} field matches exact components.
|Block predicate format has been updated:
*{{cd|tag}} field has been removed.
*{{cd|blocks}} field now supports a single entry, hash-prefixed block tag, or list of blocks.
|Fluid predicate format has been updated:
*{{cd|tag}} field has been removed.
*{{cd|fluid}} renamed to {{cd|fluids}}, and supports a single entry, hash-prefixed fluid tag, or list of fluids.
|Entity predicate format has been updated:
*{{cd|type}} field now supports a single entry, hash-prefixed entity type tag, or list of entity types.
|Location predicate format has been updated:
*{{cd|biome}} renamed to {{cd|biomes}}, and supports a single entry, hash-prefixed biome tag, or list of biomes.
*{{cd|structure}} renamed to {{cd|structures}}, and supports a single entry, hash-prefixed structure tag, or list of structures.
}}
|{{HistoryLine|||dev=24w10a|Added entity sub-predicate {{cd|slots}}, used to check single or multiple slots on any entity.}}
|{{HistoryLine|||dev=24w11a|Removed entity sub-predicate {{cd|any}}
Component-specific item predicate properties have been moved to separate field {{cd|predicates}}|
Item sub-predicate format has been updated:
*Some fields from item predicate have been moved to a map in an optional field {{cd|predicates}}.
*{{cd|enchantments}}, {{cd|stored_enchantments}}, {{cd|potions}}, {{cd|custom_data}} fields have been moved to {{cd|minecraft:enchantments}}, {{cd|minecraft:stored_enchantments}}, {{cd|minecraft:potion_contents}}, {{cd|minecraft:custom_data}} sub-predicates respectively.
*{{cd|durability}} field has been expanded to {{cd|minecraft:damage}} predicate.
*Predicates {{cd|minecraft:enchantments}}, {{cd|minecraft:stored_enchantments}}, {{cd|minecraft:potion_contents}}, {{cd|minecraft:damage}} now require matching component to exist on them.}}
|{{HistoryLine||1.21|dev=24w18a|Renamed {{cd|random_chance_with_looting}} to {{cd|random_chance_with_enchanted_bonus}}, changing the {{cd|chance}} field from a float to a level-based value, removing the {{cd|looting_multiplier}} field, and adding a {{cd|enchantment}} field.|
Changed the {{cd|chance}} field of {{cd|random_chance}} from a float into a number provider.|
Added a {{cd|can_see_sky}} field to location predicates.|
Renamed {{cd|enchantment}} to {{cd|enchantments}} in the {{cd|minecraft:enchantments}} item sub-predicate; now accepting multiple possible enchantments, or tags.|
Changes to the entity predicate:
* added {{cd|is_on_ground}} and {{cd|is_flying}} flags to flags sub-predicate.
* added {{cd|movement}} sub-predicate.
* added {{cd|periodic_ticks}} sub-predicate.|
Renamed loot context entities: {{cd|killer}} renamed to {{cd|attacker}}; {{cd|direct_killer}} renamed to {{cd|direct_attacker}}; {{cd|killer_player}} renamed to {{cd|attacking player}}.}}
|{{HistoryLine|||dev=24w19a|Added {{cd|is_direct}} field to damage type predicates.}}
|{{HistoryLine|||dev=24w21a|Added {{cd|jukebox_playable}} item predicate.|
The {{cd|gamemode}} field of the player predicate now accepts a list of gamemodes rather than a single string.}}
|{{HistoryLine|||dev=pre1|Split {{cd|chance}} into {{cd|unenchanted_chance}} and {{cd|enchanted_chance}} in the {{cd|random_chance_with_enchanted_bonus}} condition.}}
|{{HistoryLine||1.21.2|dev=24w35a|New entity sub-predicate for testing sheep wool. Fields: sheared and color.}}
|{{HistoryLine|||dev=24w36a|New entity sub-predicate for testing player input. Available inputs to test are forward, backward left, right, jump, sneak, and sprint.}}
|{{HistoryLine|||dev=24w37a|New entity sub-predicate for salmon. Fields: variant.}}
|{{HistoryLine|||dev=24w39a|Removed the minecraft:boat entity sub-predicate, since boats no longer have variants.}}
}}
== External links ==
* [https://misode.github.io/predicate/ Predicate Generator on misode.github.io]
== Navigation ==
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