Your first script

In Studio, insert a Script, paste this, and press ▶ Test. Voxa scripting is Luau-flavored: it reads like Roblox code, and it runs sandboxed, so a script can never touch a player's computer.

-- runs once when the world loads
function on_start()
  show_toast("Hello Voxa!")
  spawn_part("Floor", "Block", 0, 0, 0, 20, 1, 20, 0.3, 0.7, 0.4)
end

-- runs when a player touches this script's part
function on_touch()
  show_toast("You touched it!")
  win()
end

Basics

One statement per line. Comments start with --. Variables need no type.

score = 0
name  = "Voxa"
msg   = "Score: " + str(score)   -- + joins text; str() turns numbers into text

Operators are written like this — note these are not the Lua ones:

+  -  *  /  %        math (% is remainder)
==  !=  <  >  <=  >=  comparing  (use != , NOT ~=)
and  or  not          logic      (NOT && || !)

Handy built-ins you can use inside any expression: abs min max clamp floor ceil round sqrt sin cos randi randf str, plus .size() on a list or table. For a random 0–5: randi() % 6.

If & loops

if score > 10 then
  show_toast("Nice!")
elseif score > 5 then
  show_toast("Getting there")
else
  show_toast("Keep going")
end

for i = 0, 9, 1 do        -- start, stop (included), step
  print(i)
end

while hp > 0 do
  hp = hp - 1
end

Loops stop automatically after 100,000 rounds, so a runaway loop can't freeze anyone's game.

Lists & tables

nums = [10, 20, 30]      -- a list
nums[1] = 99             -- change an item (counting starts at 0)
push(nums, 40)           -- add to the end   (pop(nums) removes the last)
count = nums.size()

t = {}                   -- a table: store anything under a key
t["hp"] = 100
t[row * 8 + col] = 3     -- keys can be math — perfect for a grid

grid = [[1, 2], [3, 4]]  -- lists inside lists work too
grid[1][0] = 30

Functions

function add(x, y)
  return x + y
end

total = add(3, 4)   -- use the result
do_thing()          -- or just run it

Scope (where variables live)

Code in an event like on_start makes global variables. Code inside a function you wrote makes local ones that disappear when it finishes — so a function can't change a global number directly.

-- ✗ does nothing to the real score
function bump()
  score = score + 1
end

-- ✓ keep shared data in a table, which IS shared
function on_start()
  G = {}
  G["score"] = 0
end

function bump()
  G["score"] = G["score"] + 1
end

Events

Event	When it runs
on_start()	Once, when the world loads.
on_tick()	Every frame. Great for spinning or moving things.
on_touch()	A player touches the part this script is on.
on_activate()	A Tool is clicked while a player holds it.
on_<button>()	A GUI button was clicked — named after the button.
on_click()	Any GUI button was clicked. Read clicked (its name) and clicked_num (its trailing number) to tell which.
on_<name>()	Something called fire("name").

Lines written outside any function run as part of on_start. fire("my_event") runs on_my_event() on every script in the world — that's how scripts talk to each other.

Making a GUI

Create a screen once, then add elements to it. A button fires an event named exactly after the button — that's how clicks reach your code.

function on_start()
  G = {}
  G["count"] = 0
  spawn_screen_gui("Demo")
  spawn_gui("panel", "frame",  "Demo", "",          40,  40, 260, 130, 0.10, 0.11, 0.18)
  spawn_gui("lbl",   "label",  "Demo", "Clicks: 0", 40,  60, 260,  28, 0.85, 0.90, 1.00)
  spawn_gui("hit",   "button", "Demo", "Click me",  90, 110, 160,  44, 0.36, 0.35, 1.00)
end

-- the button is named "hit", so its event is on_hit
function on_hit()
  G["count"] = G["count"] + 1
  set_text("lbl", "Clicks: " + str(G["count"]))
end

Element types: frame, label, button, textbox, imagelabel, imagebutton. Positions are in pixels (x, y, width, height), colors are three 0–1 numbers.

One handler for lots of buttons. Every click also fires on_click() and sets two values: clicked (the button's name) and clicked_num (its trailing digits as a number, or −1). So a whole grid needs one handler, not one per cell:

-- 64 buttons named c0 … c63, handled once
function on_click()
  if clicked_num >= 0 then
    tap(clicked_num)
  end
end

Common mistakes

All commands

Every command works both in Studio ▶ Test and in a published world. A test: simulated tag means Test fakes it — because an editor has no network, no real purchases, and no other players — and prints what it did to the output console.

Showing all 67 commands.

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Messages

This script's own part

Building

Screen GUI

Lists, values & events

The player

Camera

The world

Smooth motion (tweens)

Teams & leaderboard

Saving & internet

Gamepasses

Automatic triggers

Other