Variables and Values

Written: 2026-10-14

Learning objectives

• You explain what a variable is in your own words.
• You create variables with local and give them values with =.
• You name variables with camelCase and full words.
• You tell values apart from the variables that hold them.

Prerequisites

• Read First Script. You already ran code and pressed Play.

What a variable is

A variable is a name you give to a value so you can use it later. Think of it as a label on a box. The label is the variable. The thing inside the box is the value.

Values are the actual data. "Maya" is a value. 10 is a value. true is a value. A variable is the name you stick on one of those values so your code can find it again.

Run this: put it in a Script in ServerScriptService and press Play.

--!strict
local playerName = "Maya"
print(playerName)

Maya

Walkthrough:

1. Line 1 turns on strict mode. Every script in this course starts with it.
2. Line 2 creates a variable called playerName and puts the value "Maya" inside it.
3. Line 3 prints whatever playerName currently holds.

Create variables with local

You create a variable in two steps. Write local, then the name, then =, then the value. The = sign is called assignment. It copies the value on the right into the variable on the left.

The word local matters. It keeps the variable inside your script. Without it, the variable leaks into a shared global place and runs slower. Always write local. You can read more about why in scope.

Run this: put it in a Script in ServerScriptService and press Play.

--!strict
local score = 0
print(score)
score = 10
print(score)

0
10

Walkthrough:

1. Line 1 turns on strict mode.
2. Line 2 creates score and assigns it 0.
3. Line 3 prints 0, the current value of score.
4. Line 4 assigns a new value, 10, to the same variable. The old 0 is gone.
5. Line 5 prints 10.

Notice that line 4 has no local. You use local once, when you create the variable. After that you assign with a plain =.

You can also create a variable with no value yet. It then holds a special value called nil, which means "nothing here". You will meet nil properly in Strings, Numbers, and Nil.

Run this: put it in a Script in ServerScriptService and press Play.

--!strict
local nickname = "Max"
local teamScore = 4
local finished = false
print(nickname)
print(teamScore)
print(finished)

Max
4
false

Walkthrough:

1. Line 1 turns on strict mode.
2. Line 2 stores the strings value "Max" in nickname.
3. Line 3 stores the numbers value 4 in teamScore.
4. Line 4 stores the booleans value false in finished.
5. Lines 5 to 7 print each variable in order.

Names that help you

Good names make your code read like sentences. Follow three rules.

First, use camelCase. Start with a lowercase letter. Capitalize the first letter of each extra word. No spaces, no dashes.

Second, spell words out fully. teamScore beats ts. playerName beats pn. You read code far more often than you type it.

Third, say what the thing means, not what type it is. winnerName beats string1.

Run this: put it in a Script in ServerScriptService and press Play.

--!strict
local winnerName = "Maya"
local runnerUpName = "Rio"
print(winnerName)
print(runnerUpName)

Maya
Rio

Walkthrough:

1. Line 1 turns on strict mode.
2. Line 2 creates winnerName. Each word after the first starts uppercase.
3. Line 3 creates runnerUpName with the same style.
4. Lines 4 and 5 print both values.

Names must start with a letter or an underscore. They can contain letters, digits, and underscores after that. They cannot be reserved words like if, then, local, or true. Names are case-sensitive, so score and Score are two different variables.

Values live on their own

A variable only points at a value, which exists on its own. Two variables can point at the same value. Changing one variable never changes the other.

Run this: put it in a Script in ServerScriptService and press Play.

--!strict
local firstPick = "apple"
local secondPick = firstPick
print(firstPick)
print(secondPick)
firstPick = "pear"
print(firstPick)
print(secondPick)

apple
apple
pear
apple

Walkthrough:

1. Line 1 turns on strict mode.
2. Line 2 puts the value "apple" in firstPick.
3. Line 3 copies the current value of firstPick into a new variable called secondPick. Now both hold "apple".
4. Lines 4 and 5 print apple twice.
5. Line 6 gives firstPick a new value, "pear". This touches only firstPick.
6. Line 7 prints pear for firstPick.
7. Line 8 prints apple for secondPick. It kept its own copy.

This split causes many beginner bugs. When output looks wrong, ask yourself: which variable did I actually change, and which one did I actually print?

Common mistakes

Forgetting local.

Run this to see the sloppy version: put it in a Script in ServerScriptService and press Play.

--!strict
score = 5
print(score)

5

This prints 5, but score becomes a global variable. Strict mode underlines it, and globals run slower. Fix it by adding local where you create the variable. Run the fix the same way.

--!strict
local score = 5
print(score)

5

Putting spaces or dashes in names.

Run this to see it fail: put it in a Script in ServerScriptService and press Play.

--!strict
local team score = 4
print(team score)

Red syntax error on line 2: the script does not run until you fix the name.

Luau reads team and score as two separate names. Fix it with camelCase. Run the fix the same way.

--!strict
local teamScore = 4
print(teamScore)

4

Mixing up the value and the variable.

Run this to see it fail: put it in a Script in ServerScriptService and press Play.

--!strict
local playerName = Maya
print(playerName)

nil

Maya with no quotes is read as a variable name. That variable does not exist, so strict mode flags it and it arrives as nil. Fix it by quoting text values. Run the fix the same way.

--!strict
local playerName = "Maya"
print(playerName)

Maya

Reusing local on every assignment.

Run this: put it in a Script in ServerScriptService and press Play.

--!strict
local score = 0
local score = 10
print(score)

10

This prints 10, but the second local builds a brand-new variable that hides the first one. Two variables with one name confuse every reader. Fix it by assigning without local after creation. Run the fix the same way.

--!strict
local score = 0
score = 10
print(score)

10

Exercises

Run every solution below in a Script in ServerScriptService and press Play. Try each exercise yourself before you open its solution.

1. Create a variable called petName with your favorite animal name in it. Print it.

Solution 1

--!strict
local petName = "Biscuit"
print(petName)

Biscuit

2. Create coins with the value 20. Print it. Then change coins to 35 and print it again.

Solution 2

--!strict
local coins = 20
print(coins)
coins = 35
print(coins)

20
35

3. Create firstName and lastName with two words in them. Print each one on its own line.

Solution 3

--!strict
local firstName = "Maya"
local lastName = "Reyes"
print(firstName)
print(lastName)

Maya
Reyes

4. Predict the output before you run it. Then run it and check yourself.

Solution 4

--!strict
local greeting = "hi"
local copiedGreeting = greeting
greeting = "bye"
print(greeting)
print(copiedGreeting)

bye
hi

The third line copies "hi" into copiedGreeting. The fourth line changes only greeting, so copiedGreeting still prints hi.

Summary

You learned that a variable is a named label for a value. You create variables with local, assign values with =, and name them in camelCase with full words. Values stand on their own, and each variable holds its own copy.

Next: Operators and Logic.