Glossary

Words underlined like this across the guide show these definitions when you hover them.

client: A player's copy of the game. It runs the same scripts, and shows the player what the server decided.
component: One script attached to one entity. The same script on ten entities is ten components, each with its own copy of the script's fields.
constant: A field declared with plain let. The script cannot change it while running, but a level can set a different value for each placed component in the editor.
entity: A thing in the game world: a player, a ball, a trigger, an empty marker. On its own it only has a name and a place in the hierarchy; components give it behaviour.
event: A function the engine (or another script) calls on your component when something happens: every frame, when it is created, when something overlaps a trigger.
field: A variable declared at the top of a script. Every component made from the script has its own copy.
hierarchy: The parent/child tree entities form. Moving a parent moves its children with it.
inheritance: Building one script on another with super: yours gets the parent's fields and functions and changes only what it needs to.
level: A file of entities: a map, or a smaller piece placed inside one.
list: An ordered collection of values, read and written by position, starting at 0.
local: A variable declared with let inside a function. It exists only until the function returns.
mutable: A field declared with let mut. The script's running state: it changes while the game runs.
native: A function built into the engine, called with a $ in front: $entity.get_name(e). Natives are how a script reaches anything outside itself.
null: No value: the answer when there is no such entity, no such component, nothing to return.
prefab: A level built to be placed many times. Each placement is an instance, and its entities become children of the entity that places it.
replication: The server sending a component's changed fields to every client, so they all agree.
script: A .vscript file. It describes one kind of component: its fields and what it does when the engine calls it.
server: The machine that runs the match and decides what really happened. Every player's game talks to it.
tick: One step of the game's simulation. The engine runs one tick per frame and calls your tick events in it.
user: A person playing, or a bot. Players, the balls they hold and the things they spawn are owned by a user.