#Scripting overview

Studz games are scripted in Lua 5.4 with an API that grew out of Roblox's. If you have written Roblox scripts, most of what you know carries over, and the Roblox spellings still run (with a warning that names the Studz one). This page covers what you need before writing your first script: where scripts run, what the language is, and the rules every script lives by.

#The language

Scripts are plain Lua 5.4, not Luau. These Luau conveniences do not exist:

• compound assignment (x += 1; write x = x + 1)
• continue
• type annotations
• string interpolation (use .. or string.format)

Some Luau library functions are provided anyway: math.clamp, math.sign, math.round, math.lerp, table.find, table.clone, table.clear, typeof, task.* and tick. See Globals and services.

#How the API is named

The API has one official spelling for everything, in PascalCase.

A few names are shared with Roblox on purpose and are not deprecated: Instance.new, Destroy, Clone, IsA, Touched, TweenService:Create, Raycast, CFrame, Vector3, Color3 and the other value types.

#Where scripts run

There are three kinds of script. Add them from the Script ribbon or the Explorer in Polycarbonate.

#What the server shows to everyone

Everything a server Script does to the world is replicated, so every player sees it:

• Parts it creates, moves, recolours, resizes, makes transparent or non-collidable, or destroys. This includes unanchored parts that physics moves.
• The Lighting service (time of day, brightness).
• GUI made with Instance.new("TextLabel"), "TextButton" or "Frame" in a server script. All players see it, and a click on a button runs its handler on the server.
• Sounds started with Sound.play, or by setting a Sound object's Playing, which play on every client.

Positions a script assigns are authoritative. Setting part.Position on an unanchored part teleports its physics body there. The source of a server Script is never sent to players.

#What fires on the server

Touched, TouchEnded and PlayerTouched fire on the server with the touching player's character. Clicking a part runs its ClickDetector.MouseClick or part.Clicked handler for that player, provided they are within 64 studs.

#Testing

Use Test > Local Server in Polycarbonate to run the server and a player separately, the way the live game runs. LocalScripts and remotes only work there. The single-process Play (F5) playtest does not run them. See Client and server.

#Errors that help

Studz turns many silent mistakes into errors that say what to fix.

#Errors name the script

Scripts load under their own name, so an error in the Output window reads DoorOpener:14: attempt to .... Unnamed scripts appear as Script#<id>. A required module reports under the module's name.

#Unknown members are errors

A member the object does not have raises an error with a suggestion. This is checked for each kind of object (parts, lights, value objects, sounds, GUI elements, humanoids):

part.Transparancy = 1
-- 'Transparancy' is not a valid property of Part (did you mean 'Transparency'?)
print(part.Health)
-- 'Health' is not a valid member of Part

Containers, services and players are open ended instead: workspace.Foo is nil when nothing is called Foo.

#Wrong types are errors

part.Transparency = "high"
-- Part.Transparency expects a number, got string

Numbers and vectors must be finite. NaN and infinity are refused, so one bad calculation cannot corrupt a position.

#Other checks

#Limits

Game servers share a machine, so everything a script can allocate has a ceiling. Hitting one raises an error in the script that did it. Nothing else is affected.

#Sandbox

Scripts cannot reach the machine they run on. There is no io, no package, no dofile or loadfile, no debug, no binary chunks and no collectgarbage control. os offers only os.time, os.clock, os.date and os.difftime. HttpService cannot make web requests.

#Where to go next