Roblox Studio & Lua Cheat Sheet

🧱 Lua Basics

Variables & Types

Numberlocal x = 42

Stringlocal s = "Hello"

Booleanlocal b = true

Nil (empty)local n = nil

Table (list)local t = {1, 2, 3}

String concat"Hi " .. name

String length#myString

Table length#myTable

Conditions

Equalx == y

Not equalx ~= y

Greater thanx > y

Less or equalx <= y

Andx > 0 and y > 0

Orx == 1 or x == 2

Notnot myBool

If / elseif / elseif … elseif … else … end

Loops

Count upfor i = 1, 10 do … end

Count downfor i = 10, 1, -1 do … end

Loop tablefor i, v in ipairs(t) do … end

While loopwhile condition do … end

Infinite loopwhile true do … end

Break outbreak

Skip stepcontinue

Pause in looptask.wait(1)

Functions & Math

Declarelocal function greet() end

With parameterlocal function add(a, b) end

Return valuereturn a + b

Call itgreet()

Random numbermath.random(1, 6)

Round downmath.floor(3.7)

Round upmath.ceil(3.2)

Format stringstring.format("%02d", 5)

🔧 Common Services

ℹ️

Always use game:GetService("Name") at the top of your script — it's more reliable than game.ServiceName.

Getting Services

Playersgame:GetService("Players")

TweenServicegame:GetService("TweenService")

RunServicegame:GetService("RunService")

DataStoreServicegame:GetService("DataStoreService")

SoundServicegame:GetService("SoundService")

Debrisgame:GetService("Debris")

HttpServicegame:GetService("HttpService")

Players Service

All playersPlayers:GetPlayers()

Local playerPlayers.LocalPlayer

From characterPlayers:GetPlayerFromCharacter(char)

Respawn timePlayers.RespawnTime = 5

Player nameplayer.Name

Player IDplayer.UserId

Player charplayer.Character

TweenService

TweenInfoTweenInfo.new(time, style, dir, reps, rev)

Create tweenTweenService:Create(obj, info, {prop=val})

Playtween:Play()

Easing styleEnum.EasingStyle.Sine

Easing dirEnum.EasingDirection.InOut

Loop foreverrepeats = -1

Ping-pongreverses = true

DataStoreService

Get storeDSS:GetDataStore("StoreName")

Save datastore:SetAsync("key", value)

Load datastore:GetAsync("key")

Update datastore:UpdateAsync("key", fn)

Safe callpcall(function() … end)

Enable in StudioGame Settings → Security → API Services

⚡ Events & Connections

Part & Character

Part touchedpart.Touched:Connect(fn)

Stop touchingpart.TouchEnded:Connect(fn)

Click detectorcd.MouseClick:Connect(fn)

Proximity promptprompt.Triggered:Connect(fn)

Humanoid diedhumanoid.Died:Connect(fn)

Health changedhumanoid.HealthChanged:Connect(fn)

MoveTo finishedhumanoid.MoveToFinished:Connect(fn)

Player Events

Player joinedPlayers.PlayerAdded:Connect(fn)

Player leftPlayers.PlayerRemoving:Connect(fn)

Char spawnedplayer.CharacterAdded:Connect(fn)

Char removedplayer.CharacterRemoving:Connect(fn)

Value changedvalue.Changed:Connect(fn)

Attribute changedplayer.AttributeChanged:Connect(fn)

RemoteEvents

CreateInstance.new("RemoteEvent")

Parent toevent.Parent = ReplicatedStorage

Fire one clientevent:FireClient(player, data)

Fire all clientsevent:FireAllClients(data)

Fire serverevent:FireServer(data)

Listen (client)event.OnClientEvent:Connect(fn)

Listen (server)event.OnServerEvent:Connect(fn)

RunService

Every frame (server)RunService.Heartbeat:Connect(fn)

Every frame (client)RunService.RenderStepped:Connect(fn)

Is server?RunService:IsServer()

Is client?RunService:IsClient()

Disconnectlocal c = …:Connect(fn); c:Disconnect()

🏗️ Instances & Properties

Creating & Finding

New instanceInstance.new("Part")

Set parentobj.Parent = workspace

Find childparent:FindFirstChild("Name")

Wait for childparent:WaitForChild("Name")

Find by classparent:FindFirstChildOfClass("Humanoid")

Get childrenparent:GetChildren()

Cloneobj:Clone()

Destroyobj:Destroy()

Part Properties

Positionpart.Position = Vector3.new(0,5,0)

Sizepart.Size = Vector3.new(4,1,4)

Colourpart.BrickColor = BrickColor.new("Red")

Materialpart.Material = Enum.Material.Neon

Anchoredpart.Anchored = true

Can collidepart.CanCollide = false

Transparencypart.Transparency = 0.5

Distance(a.Position - b.Position).Magnitude

Humanoid

Healthhumanoid.Health

Max healthhumanoid.MaxHealth

Kill playerhumanoid.Health = 0

Walk speedhumanoid.WalkSpeed = 16

Jump powerhumanoid.JumpPower = 50

Move to poshumanoid:MoveTo(Vector3)

Root partchar.HumanoidRootPart

Values & Attributes

Set attributeobj:SetAttribute("Name", value)

Get attributeobj:GetAttribute("Name")

Attribute changedobj.AttributeChanged:Connect(fn)

Leaderstatsplayer.leaderstats.Gold.Value

IntValueInstance.new("IntValue")

StringValueInstance.new("StringValue")

Auto-removegame.Debris:AddItem(obj, 3)

📐 Vectors, Positions & GUI Sizes

💡

These trip up almost every beginner. Bookmark this section — you'll come back to it in every episode.

Vector3 — 3D Space

CreateVector3.new(x, y, z)

ZeroVector3.new(0, 0, 0)

Up 10 studsVector3.new(0, 10, 0)

Add vectorsv1 + v2

Scalev * 2

Distance(a - b).Magnitude

Lerp (smooth)a:Lerp(b, 0.1)

Normalisev.Unit

UDim2 — GUI Size & Position

SyntaxUDim2.new(scX, offX, scY, offY)

Full screenUDim2.new(1, 0, 1, 0)

Half widthUDim2.new(0.5, 0, 1, 0)

Fixed 200px wideUDim2.new(0, 200, 0, 50)

Centre positionUDim2.new(0.5, 0, 0.5, 0)

Top-leftUDim2.new(0, 0, 0, 0)

Bottom-rightUDim2.new(1, 0, 1, 0)

AnchorPoint centreVector2.new(0.5, 0.5)

CFrame — Position & Rotation

At positionCFrame.new(x, y, z)

From Vector3CFrame.new(Vector3)

Look at targetCFrame.lookAt(pos, target)

Rotate XCFrame.Angles(math.rad(90),0,0)

Move relativepart.CFrame * CFrame.new(0,5,0)

Get positionpart.CFrame.Position

Lerp (smooth)cf1:Lerp(cf2, 0.1)

Colour & BrickColor

By nameBrickColor.new("Bright red")

RandomBrickColor.random()

From RGBColor3.fromRGB(255, 100, 0)

WhiteColor3.new(1, 1, 1)

BlackColor3.new(0, 0, 0)

Common namesReally red · Lime green · Cyan · White · Black · Gold

Set part colourpart.BrickColor = BrickColor.new("…")

⌨️ Roblox Studio Keyboard Shortcuts

Testing

Play gameF5

Stop gameShift+F5

Pause gameF6

Run (no player)F8

Open OutputView → Output

2-player testTest → Clients and Servers

Transform Tools

Select toolQ

Move toolW

Scale toolR

Rotate toolE

Move cameraRight-click + WASD

Focus on partF (part selected)

Editing

UndoCtrl+Z

RedoCtrl+Y

Copy / PasteCtrl+C / Ctrl+V

DuplicateCtrl+D

DeleteDelete or Backspace

Select allCtrl+A

Save fileCtrl+S

Parts & Groups

Group partsCtrl+G

UngroupCtrl+Shift+G

Toggle anchorAlt+A

Insert PartHome tab → Part

Open ToolboxView → Toolbox

Snap to gridHold Shift while moving

📍 Where Things Go in Explorer

Scripts

Server ScriptServerScriptService

LocalScriptStarterPlayerScripts

LocalScript (char)StarterCharacterScripts

Script in partInside the Part itself

Module scriptReplicatedStorage

GUI & Tools

ScreenGuiStarterGui

BillboardGuiInside the Part

SurfaceGuiInside the Part

Starting toolStarterPack

Tool in worldWorkspace

Tool to give laterServerStorage → clone to Backpack

Shared & Hidden

RemoteEventsReplicatedStorage

BindableEventsServerScriptService

Hidden assetsServerStorage

Shared modulesReplicatedStorage

Lighting effectsLighting (in Explorer)

Sounds (global)Workspace

📋 Ready-to-Use Code Patterns

💡

Hit Copy on any pattern, paste it into your script, then fill in the blanks. The episode tags show where each pattern first appears in the series.

          
          Leaderstats Setup (server)
          
          Ep 2Ep 3
          
        
local Players = game:GetService("Players")
Players.PlayerAdded:Connect(function(player)
    local ls = Instance.new("Folder")
    ls.Name = "leaderstats"
    ls.Parent = player
    local coins = Instance.new("IntValue")
    coins.Name = "Coins"
    coins.Value = 0
    coins.Parent = ls
end)

          
          Part Touched — get player
          
          Ep 1Ep 2Ep 3
          
        
part.Touched:Connect(function(hit)
    local player = game.Players
        :GetPlayerFromCharacter(hit.Parent)
    if not player then return end
    -- do something with player here
    player.leaderstats.Coins.Value += 1
end)

          
          Moving Platform (TweenService)
          
          Ep 1
          
        
local TS = game:GetService("TweenService")
local info = TweenInfo.new(2,
    Enum.EasingStyle.Sine,
    Enum.EasingDirection.InOut,
    -1, true)
local goal = {Position = platform.Position
    + Vector3.new(0, 10, 0)}
TS:Create(platform, info, goal):Play()

          
          DataStore Save & Load
          
          Ep 3Ep 6
          
        
local DSS = game:GetService("DataStoreService")
local store = DSS:GetDataStore("MyStore")
-- Save on PlayerRemoving:
pcall(function()
    store:SetAsync("player_"..player.UserId,
        {Coins = coins.Value})
end)
-- Load on PlayerAdded:
local ok, data = pcall(function()
    return store:GetAsync("player_"..player.UserId)
end)
if ok and data then
    coins.Value = data.Coins or 0
end

          
          GUI Label Update (LocalScript)
          
          Ep 2Ep 3Ep 4
          
        
local player = game.Players.LocalPlayer
local coins = player.leaderstats
    :WaitForChild("Coins")
local label = player.PlayerGui
    .MyGui.Frame.CoinsLabel

local function update()
    label.Text = "🪙 " .. coins.Value
end
coins.Changed:Connect(update)
update()

          
          Chase Nearest Player (Heartbeat)
          
          Ep 5Ep 6
          
        
local RS = game:GetService("RunService")
local Players = game:GetService("Players")
RS.Heartbeat:Connect(function()
    local nearest, minD = nil, math.huge
    for _, p in ipairs(Players:GetPlayers()) do
        if p.Character then
            local d = (npc.Position
                - p.Character.HumanoidRootPart.Position).Magnitude
            if d < minD then
                nearest = p.Character; minD = d
            end
        end
    end
    if nearest then
        humanoid:MoveTo(nearest.HumanoidRootPart.Position)
    end
end)

          
          RemoteEvent — server to all clients
          
          Ep 4Ep 5Ep 6
          
        
-- SERVER SCRIPT: create & fire
local RS = game.ReplicatedStorage
local evt = Instance.new("RemoteEvent")
evt.Name = "MyEvent"
evt.Parent = RS
evt:FireAllClients("Hello everyone!")

-- LOCAL SCRIPT: listen
local evt = game.ReplicatedStorage
    :WaitForChild("MyEvent")
evt.OnClientEvent:Connect(function(msg)
    print("Received:", msg)
end)

          
          Kill on Touch + debounce
          
          Ep 1
          
        
local debounce = {}
part.Touched:Connect(function(hit)
    local hum = hit.Parent:FindFirstChildOfClass("Humanoid")
    if not hum then return end
    if debounce[hum] then return end
    debounce[hum] = true
    hum.Health = 0
    task.wait(1)
    debounce[hum] = nil
end)

🚨 Common Errors & How to Fix Them

⚠️

Always check the Output window (View → Output) when something doesn't work. Errors appear in red and tell you the exact line number.

attempt to index nil value 'leaderstats'

What it means: You're trying to use leaderstats but it doesn't exist yet on that player.

Fix: Make sure PlayerAdded runs before any script tries to read leaderstats. Use player:WaitForChild("leaderstats") in LocalScripts instead of accessing it directly.

attempt to index nil value (local 'player')

What it means: GetPlayerFromCharacter returned nil — the thing that touched the part wasn't a player.

Fix: Always add if not player then return end right after calling GetPlayerFromCharacter. This guards against bullets, NPCs or other parts firing the Touched event.

Infinite yield possible on 'WaitForChild("…")'

What it means: The script is waiting for something that never appears. It will wait forever (and everything below it never runs).

Fix: Check the spelling — it's case-sensitive. Also make sure the thing you're waiting for actually exists and is in the right place in Explorer. Common typo: "leaderstats" vs "LeaderStats".

X is not a valid member of Y

What it means: You're looking for something inside an object that isn't there — wrong parent, wrong name, or it hasn't been created yet.

Fix: Open Explorer and check the exact name and location. Use :WaitForChild() instead of a direct .Name access if the item is created at runtime. Remember names are case-sensitive.

Script timeout: exhausted allowed execution time

What it means: Your script has an infinite loop that never yields — it's hogging all the CPU.

Fix: Any while true do loop must have a task.wait() inside it. Without a wait, Roblox kills the script after a few seconds. Add task.wait(0.1) at the bottom of the loop.

DataStore request was throttled (too many requests)

What it means: You're calling SetAsync or GetAsync too often. Roblox limits how fast you can use DataStores.

Fix: Only save data when the player leaves (PlayerRemoving), not every time a value changes. Wrap all DataStore calls in pcall so a throttle error doesn't crash your script.

LocalScript in ServerScriptService is not allowed

What it means: You put a LocalScript in the wrong place. LocalScripts only run in StarterGui, StarterPlayerScripts, StarterCharacterScripts, or a player's Backpack.

Fix: Move it to StarterPlayerScripts. If you need it to run when the character spawns, put it in StarterCharacterScripts instead.

Unable to cast value to Object

What it means: You passed the wrong type to a function — usually giving a string where an object is expected, or vice versa.

Fix: Check what the function expects. For example, humanoid:MoveTo() needs a Vector3, not a Part. Use part.Position to get the Vector3 out of a part.