Entity Condition Types

An entity condition checks the state of a single entity and returns true or false. The entity being tested is supplied by whatever data table declares the condition, so the condition itself only describes what to check.

Entity conditions are a Java (built-in) registry, so their type ids are fixed and a data pack cannot add new ones. type selects the built-in type and its value is one of the ids tabulated on this page, written with the mxt namespace. A data pack never adds or removes entries in this registry. Only Java code or the KubeJS bridge can introduce custom condition types — see the KubeJS API.

In the table below, a field name followed by ? is optional; every other listed field must be present. The Fields column lists the JSON keys taken directly from the type's codec.

Common Structure

A condition is a JSON object whose type field names the built-in type. All remaining keys are the fields declared by that type.

{
  "type": "mxt:health",
  "comparison": "<",
  "compare_to": 10
}

Because conditions are used as values inside other data tables, the same structure usually appears nested under a field such as condition:

"condition": {
  "type": "mxt:has_spirit_root",
  "spirit_root": "example:azure_root"
}

Anywhere an entity condition is expected, an array of conditions is also accepted. The array is shorthand for mxt:and and passes only when every entry passes:

"condition": [
  { "type": "mxt:sneaking" },
  { "type": "mxt:on_block", "condition": {"type": "mxt:block_tag", "tag": "minecraft:logs"} }
]

Comparison Fields

Several types compare a value against a number. When a type lists comparison and compare_to as separate keys, they sit directly on the condition object, as in the example above. A few types instead name a single comparison key whose value is one nested comparison object holding comparison and compare_to; those types say so in their description. The comparison operators are ==, !=, <, <=, > and >=, and compare_to itself is always a plain number.

Datapack Visual Editor

The Datapack Visual Editor shows the field list of every type interactively, which is handy for checking a field name without reading the table here.

Condition Types

Type	Fields	Description
mxt:always_true	—	Always passes.
mxt:js	id, params?	Calls an entity condition handler that was registered through the KubeJS bridge.
mxt:never	—	Always fails.
mxt:and	conditions	Passes only when every nested entity condition passes.
mxt:not	condition	Negates a nested entity condition.
mxt:or	conditions	Passes when at least one nested entity condition passes.
mxt:chance	chance	Passes randomly with the given probability between 0 and 1.
mxt:constant	value	Always returns the given boolean value.
mxt:sneaking	—	Checks whether the entity is sneaking.
mxt:has_ability	ability	Checks whether the entity currently holds the given ability.
mxt:has_curse	curse?, tags?, stacks?, remaining_ticks?	Checks whether the entity holds one curse that satisfies every filter given: a definition, all of the listed tags, a stack range and a remaining-tick range. The ranges are {min?, max?} windows; a curse that never expires counts as infinite, so it answers a min but never a max. With no filter at all it asks whether any curse is held.
mxt:has_spirit_root	spirit_root	Checks whether the entity currently holds the given spirit root.
mxt:has_physique	physique	Checks whether the entity currently holds the given physique.
mxt:realm	realm, comparison?	Compares the entity's realm stage against realm, using exact (the default), at_least or at_most.
mxt:has_realm	aura	Passes for entities that have entered a realm chain for the given aura.
mxt:aura_range	aura	Tests the server-resolved aura concentration at the entity's position against per-aura requirements. aura maps an aura ID to an object with a required max and an optional min (default 0); both accept a number provider.
mxt:resource_compare	resource, min	Checks that the entity's value for a resource is at least min.
mxt:entity_tag	tag	Matches the entity against an entity type tag.
mxt:formation_member	—	Passes when the entity owns any registered formation in the current level.
mxt:formation_owner	—	Passes when the entity owns the formation currently being evaluated; outside a formation context it is false.
mxt:formation_ally	—	Passes when the owner of the formation currently being evaluated treats the entity as an ally.
mxt:air	comparison, compare_to	Compares the entity's remaining air.
mxt:dimension	dimension, inverted?	Checks the entity's dimension, or the opposite when inverted is true.
mxt:entity_type	entity_type	Checks the entity's type.
mxt:fall_distance	comparison, compare_to	Compares the entity's fall distance.
mxt:glowing	—	Checks whether the entity is glowing.
mxt:health	comparison, compare_to	Compares the entity's current health.
mxt:exposed_to_sky	—	Checks whether the entity's position can see the sky.
mxt:food_level	comparison, compare_to	Compares a player's food level.
mxt:mob_effect	effect	Checks whether the entity has the given status effect.
mxt:on_block	condition	Tests a block condition against the block the entity stands on.
mxt:time_of_day	comparison, compare_to	Compares the overworld clock time, in ticks within a 24000 tick day.
mxt:using_item	—	Checks whether the entity is currently using an item.
mxt:brightness	comparison, compare_to	Compares the brightness at the entity's eyes as a value between 0 and 1.
mxt:exposed_to_sun	—	Checks whether the entity is exposed to sunlight.
mxt:experience_level	comparison, compare_to	Compares a player's experience level.
mxt:experience_points	comparison, compare_to	Compares a player's total experience points.
mxt:relative_health	comparison, compare_to	Compares the entity's health divided by its maximum health.
mxt:saturation_level	comparison, compare_to	Compares a player's saturation level.
mxt:team	team?	Checks whether the entity is on a scoreboard team, or on the named team when team is present.
mxt:attribute	attribute, comparison, compare_to	Compares one of the entity's attribute values.
mxt:block_collision	offset_x?, offset_y?, offset_z?	Checks for a block collision at an offset from the entity.
mxt:can_have_effect	effect	Checks whether the entity can be affected by the given status effect.
mxt:gamemode	gamemode	Checks a player's game mode.
mxt:passenger	bientity_condition?, comparison, compare_to	Compares the number of the entity's direct passengers that satisfy a bi-entity condition.
mxt:attack_cooldown	comparison, compare_to	Compares a player's current attack cooldown progress.
mxt:equipped_item	equipment_slot, item_condition?	Checks the item in one equipment slot against an item condition.
mxt:in_block	block_condition	Tests a block condition against the single block at the entity's block position.
mxt:in_block_anywhere	block_condition, comparison	Compares the number of matching blocks inside the entity's bounding box, with comparison as a nested comparison object.
mxt:scoreboard	name?, objective, comparison, compare_to	Compares a scoreboard score, defaulting the score holder to the entity's scoreboard name.
mxt:riding	bientity_condition?	Checks the entity's vehicle against a bi-entity condition.
mxt:riding_recursive	bientity_condition?, comparison, compare_to	Compares the number of vehicles in the whole riding chain that satisfy a bi-entity condition.
mxt:passenger_recursive	bientity_condition?, comparison, compare_to	Compares the number of nested passengers that satisfy a bi-entity condition.
mxt:riding_root	bientity_condition?	Tests a bi-entity condition against the vehicle at the root of the entity's riding chain.
mxt:storage_toggle	family, id, expected?	Reads a mxt:toggle value. family names the data pack registry the host lives in, id the host; the host must declare that kind or the test is false. True when the stored state equals expected (default true), falling back to the declaration's default while nothing was ever written.
mxt:storage_timer	family, id, remaining?, ended?	Reads a mxt:timer value. remaining is a {min?, max?} window over the ticks left (never negative), ended asks whether ends_at has passed. A timer with no ends_at is not running, so it has nothing left and counts as ended.
mxt:storage_resource	family, id, amount?	Reads a mxt:resource value. amount is a {min?, max?} window; a stored record without an amount counts as 0, and omitting amount only asks whether a value of that kind is stored at all.
mxt:storage_target	family, id, locked?, max_distance?	Reads a mxt:target_lock value. locked (default true) asks whether a target UUID is stored; max_distance additionally requires that UUID to parse and resolve to an entity in the actor's level within that distance. A malformed UUID, a missing entity or a negative distance is false.
mxt:storage_charges	family, id, remaining?	Reads a mxt:charges value. remaining is a {min?, max?} window over the uses left; a pool that was never spent keeps no count and reads as the declaration's maximum. Omitting remaining only asks whether the host declares a charge pool at all.
mxt:storage_cooldown	family, id, remaining?, ready?	Reads a mxt:cooldown value. remaining is a {min?, max?} window over the ticks left and ready asks whether the cooldown has finished. The length is the one the last use actually got, or the declaration's own ticks for a value content wrote without a duration; the countdown starts at the tick the value was written, the same anchor the runtime reads. A host that never wrote one is not cooling down at all, so it answers remaining 0 and ready true.
mxt:has_equipped_item	item_condition?, slots?	Passes when the entity wears or holds a stack satisfying an item condition — the natural way to gate a passive mxt:modifier on gear, for example {"type": "mxt:item_tag", "tag": "#example:swords"}. slots names vanilla equipment slots (mainhand, offhand, head, chest, legs, feet, body) or Curios slots with a curios: prefix (curios:back_weapon); leaving it out asks every vanilla slot and every Curios slot. A name that matches nothing simply never passes.

Type References

ability, curse, spirit_root, physique, realm, aura and resource accept the ids of the matching data pack registries, so they can point at content added by any data pack, not only at entries shipped with the mod.