Ability Target Selectors (ability_target_selector_type)

ability_target_selector_type decides which entities an ability's bi-entity behaviour applies to. It is written in the ability's top-level target_selector, and the default is mxt:self.

ability_target_selector_type

The three selectors mxt:area / mxt:ray / mxt:cone all take include_actor, limit and order; mxt:self and mxt:js have none of those three fields — mxt:self always selects the caster alone, and mxt:js hands over however many the script returns.

When it is read is decided by the ability type:

• mxt:active, mxt:triggered, mxt:channelled and mxt:interval go through the selector every time they run their actions.
• mxt:aura reads it only when it is fired one-off (a command, a script or a talisman); its own recurring pulses do not read the selector and pick entities by radius alone.
• mxt:targeted uses it to ask "who does this cast reach": an area skill and a raycast skill differ in this selector alone — one writes radius, the other length, and both have to state a distance.

mxt:self

Selects the ability's caster only.

It has no fields; the whole selector is {"type": "mxt:self"}.

{"type": "mxt:self"}

mxt:area

A box centred on the caster (or on this invocation's origin).

Field	Type	Default	Description
radius	NumberProvider	required	The box's radius
include_actor	Boolean	false	Whether the caster is included in the selection
limit	Integer	0	At most how many targets to keep
order	nearest / farthest / random	nearest	Which targets survive when there are more than limit

The shape of the box: with no origin it is the actor's own collision box widened by radius, and with one it is a cube of side 2 × radius — not a sphere.

{"type": "mxt:area", "radius": 6, "include_actor": true, "limit": 3, "order": "nearest"}

mxt:ray

A cylinder along the caster's look.

Field	Type	Default	Description
length	NumberProvider	required	How far it reaches along the look
radius	NumberProvider	0.5	The cylinder's thickness
include_actor	Boolean	false	Whether the caster is included in the selection
limit	Integer	0	At most how many targets to keep
order	nearest / farthest / random	nearest	Which targets survive when there are more than limit

The cylinder starts at the eye position (or this invocation's origin), is length blocks long and radius blocks thick.

{"type": "mxt:ray", "length": 24, "radius": 0.5, "limit": 1}

mxt:cone

A cone along the caster's look, where angle is the half-angle.

Field	Type	Default	Description
length	NumberProvider	required	How far it reaches along the look
angle	NumberProvider	required	The cone's half-angle in degrees, between 0 and 180
include_actor	Boolean	false	Whether the caster is included in the selection
limit	Integer	0	At most how many targets to keep
order	nearest / farthest / random	nearest	Which targets survive when there are more than limit

{"type": "mxt:cone", "length": 8, "angle": 30}

Both the cylinder and the cone are stopped by blocks

The mxt:ray cylinder is clipped by blocks along its centre line, so it never reaches through a wall; the mxt:cone centre line is clipped the same way, so a wall straight ahead shortens the cone. Occlusion from the side of a cone is not tested per target: a target inside the cone is selected while the centre line is clear, even with something between it and the caster.

mxt:js

Selects the entities a server script returns; it has no limit and no order.

Field	Type	Default	Description
id	String	required	Callback ID registered with MxtAbilities.selector(id, callback)
params	Object	{}	Arbitrary JSON passed to the callback

{"type": "mxt:js", "id": "example:nearest_three", "params": {"range": 12}}

The callback runs on the server while the ability executes and returns an array of entities. Every execution of the ability performs one selection, so a missing callback selects no entities and logs a warning. It never receives this invocation's origin.

These caps are clamped at runtime, not reported as errors: mxt:area's radius is clamped to 128, mxt:ray's radius to 64, mxt:ray / mxt:cone's length to 128, and a mxt:cone angle that evaluates above 180 counts as 180. The clamp is what keeps one selection from walking the whole level.

Only values written as constants are checked at load time: limit must not be negative, length must be finite and positive, mxt:ray's radius must be finite and non-negative, and angle must be between 0 and 180. mxt:area's radius is not checked at load time: a constant negative merely makes that selection empty. A value written as a formula is only settled at runtime, and an invalid evaluation makes that selection empty.

When nothing is selected: a radius that is negative or non-finite, or a length that is non-finite or non-positive, makes that selection empty. A limit of 0 or a negative number keeps everything.

order only matters when a limit is really applied: all three area-like selectors can write "the nearest three" and "a random few" with it, and ties are broken by entity id, so the same instant always selects the same beings.

Two "radii" are not the same shape: the mxt:area selector picks a box, while an mxt:aura pulse is a sphere (centred on the caster, comparing each candidate's straight-line distance). Both spell their field radius, but they cover different sets of entities.