Conditionals — if this, then that

Your scripts can count coins now. But a game needs judgment: if the player has enough coins, let them buy; if they touch a spike, they take damage; if they've won, celebrate. That judgment is conditionals, and they're how scripts make decisions.

#The basic shape

if coins >= 50 then
    print("Enough coins!")
end

Read it as: "if it's true that coins is 50 or more, run the lines inside — otherwise skip them." The lines inside only run when the condition is true.

A condition is just an expression that produces a boolean — true or false. You met booleans already; this is where they earn their keep.

local x = 10
if x > 5 then
    print("big")
else
    print("small")
end

#More branches: elseif and else

if coins >= 100 then
    print("Whale! Splurge on the deluxe pack.")
elseif coins >= 50 then
    print("Decent. You can afford the basic pack.")
else
    print("Keep grinding — not enough yet.")
end

Luau checks top to bottom: first if, then each elseif, and if none matched, it runs else. Only one branch ever runs. elseif and else are optional — a lone if is fine.

#Combining conditions

What if a sale needs two things to be true — enough coins and a membership?

if coins >= 50 and hasMembership then
    print("Welcome to the members shop.")
end

• and — both sides must be true.
• or — at least one side true.

You can chain them: if a and b or c then. Add parentheses when it gets complicated: if (a and b) or c then.

local score = 90
local hasGoldenKey = true
-- your if line here

#Common mistakes

• Using = inside an if. if coins = 50 errors. Compare with ==.
• Mixing up and and or. if a and b needs both. if a or b needs one. When in doubt, read it out loud.
• Thinking more branches run. Only the first branch whose condition is true runs. Once it matches, the rest are skipped.
• Writing a condition that's always true. if coins >= 0 is true for every non-negative number. If you meant exactly zero, write == 0.

Next: doing something over and over — loops.