Verbs

Verbs are defined as a yaml object, similar to entities.

A simple verb might look as follows.

verb: fuddle
tags:
  - transitive

Each entity will contain a list of verbs that can be used to interact with that entity, this is specified in the entities verb list.

Transitive/intransitive verbs

Verbs are either transitive, or intransitive.Transitive verbs need an object egget ballIntransitive verbs don't need an object egstand`

These are specified as tags.

Attributes

Verb attributes are prepositions that can be used to combine a verb with two objects. eg in the phrase stir soup with spoon the word with is an attribute.

An example attribute would look like:

verb: spray
tags:
  - transitive
attributes: ['on']
actions:
  spray($spray).on($that): print("You {{spray.name}} on the {{that.name}}")

verb: stir
tags:
  - transitive
attributes:
  - with

Entities specify a verb attribute in their verb with the following syntax: <verb>.<attribute>

item: soup
verbs:
  - stir
---
item: spoon
verbs:
  - stir.with

With the above items defined, you could execute stir soup with spoon

Modifiers

Modifiers are words that add extra information, such as directions.

verb: turn
tags:
  - transitive
modifiers:
  - turn_direction

In this example, a turn_direction modifier is specified. The values available are context dependent, and are based on the object they are acting on. eg

item: crank
verbs:
  - turn
modifiers:
  turn_direction:
    - clockwise
    - anticlockwise
before:
  turn(this, $turn_direction): 
    - print("The crank turns, gears grind. ")

To capture the value of a modifier in an action, you need to use the full name of the modifier (ie $turn_direction in the above example)

contexts

A verb can be made available only if it's object is in certain contexts. Eg you might need to be carrying an item before you can use it.

In this example, the hang verb can only be used on an object whose item is in the players inventory, or is being worn.

verb: hang
tags:
  - transitive
attributes:
  - "on"
contexts:
  - inventory
  - wearing
actions:
  hang($hangable).on($hanger):
    - moveItemTo(hangable, hanger)

Instant

Verbs that are tagged as instant do not take any time to execute, and won't increment the turn counter. Instant verbs, should not alter game state, and are meant for verbs such as examine.

Sub-commands (clausal verbs)

A verb can take a whole sub-command as its attribute's object, instead of a single indirect object. This is used for commanding another entity, eg tell robot to go north.

A verb becomes "clausal" by declaring a commands list: the sub-verbs it will accept. It still needs the usual transitive tag (its direct object is the entity being commanded) and an attributes entry (the connecting word, eg to).

verb: tell
tags:
  - transitive
attributes:
  - to
commands:
  - go
  - fire

item: robot
verbs:
  - tell

With the above defined (and go/fire verbs available elsewhere), tell robot to go north and tell robot to fire laser become valid commands. The sub-verb's own grammar still applies: an intransitive sub-verb with modifiers (like go) needs a modifier to complete the command, a transitive sub-verb (like fire) needs a direct object, and an attributed sub-verb (like stir) can take its own indirect object, eg tell robot to stir soup with spoon - including indirectOptional, so tell robot to stir soup alone is also valid if stir allows it.

Only the verbs listed in commands are offered after the connecting word - commands is an explicit allow-list on the commanding verb (tell), not something the commanded entity opts into.

See command matching for how to write actions that respond to a sub-command.