The Complete Beginner's Guide to Roblox Lua Scripting

What Is Lua and Why Does Roblox Use It?

Lua is a lightweight scripting language built for speed and simplicity. Roblox chose it because it runs fast inside their engine and is easy to learn compared to languages like Java or C++. Every interactive thing in a Roblox game — a door that opens, a tool that fires, a leaderboard that updates — is driven by Lua scripts.

You do not need any prior programming experience to start. If you can follow instructions and think logically, you can learn this.

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Setting Up Roblox Studio

Download Roblox Studio for free from roblox.com/create. Once installed:

1. Open Studio and create a Baseplate template
2. In the top menu, go to View → Explorer and View → Properties
3. Click View → Script Editor to open the code editor
4. In the Explorer panel, find ServerScriptService and insert a new Script

You are now ready to write your first script.

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Your First Script

Click on the Script you just created. You will see this default code:

print("Hello world!")

Press Play (F5) and look at the Output window at the bottom. You should see Hello world! appear. That is Lua running.

Now try this:

print("My name is: " .. "Alex")
print("2 + 2 = " .. tostring(2 + 2))

The .. operator joins strings together. tostring() converts a number to a string so you can print it.

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Variables and Data Types

Variables store values so you can use them later.

local playerName = "Alex"      -- string (text)
local score = 100              -- number
local isAlive = true           -- boolean (true/false)
local nothing = nil            -- nil means "no value"

print(playerName)   -- prints: Alex
print(score + 50)   -- prints: 150

Always use local for your variables. It keeps them contained to the current script and runs faster.

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If Statements

If statements let your script make decisions.

local score = 75

if score >= 90 then
    print("Grade: A")
elseif score >= 70 then
    print("Grade: B")
elseif score >= 50 then
    print("Grade: C")
else
    print("Grade: F")
end

Roblox uses then and end instead of curly braces. Every if must end with end.

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Loops

Loops repeat code. There are three main types:

Counting loop:

for i = 1, 5 do
    print("Count: " .. i)
end

While loop:

local count = 0
while count < 3 do
    count = count + 1
    print("While: " .. count)
end

For-each loop:

local fruits = {"apple", "banana", "cherry"}
for index, fruit in ipairs(fruits) do
    print(index .. ": " .. fruit)
end

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Functions

Functions are reusable blocks of code.

local function greet(name)
    return "Hello, " .. name .. "!"
end

print(greet("Alex"))   -- Hello, Alex!
print(greet("Sam"))    -- Hello, Sam!

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Working with the Roblox Engine

Changing a part's color:

local part = game.Workspace.Part
part.BrickColor = BrickColor.new("Bright red")
part.Size = Vector3.new(10, 1, 10)

Detecting when a player joins:

local Players = game:GetService("Players")

Players.PlayerAdded:Connect(function(player)
    print(player.Name .. " joined the game!")
end)

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Your First Real System: A Point Counter

Put this in a Script inside ServerScriptService:

local Players = game:GetService("Players")

Players.PlayerAdded:Connect(function(player)
    local leaderstats = Instance.new("Folder")
    leaderstats.Name = "leaderstats"
    leaderstats.Parent = player

    local points = Instance.new("IntValue")
    points.Name = "Points"
    points.Value = 0
    points.Parent = leaderstats

    while player.Parent do
        task.wait(5)
        points.Value = points.Value + 1
    end
end)

Press Play. A leaderboard appears in the top right and your points go up every 5 seconds.

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What to Learn Next

• RemoteEvents — communicate between server and client
• DataStoreService — save player data between sessions
• TweenService — smooth animations
• ModuleScripts — organise code into reusable files

Browse Roblox scripts on ModForge to study how real systems are structured.