A roblox billboard gui health bar is one of those small details that can instantly make your game feel more professional and polished. If you've ever played an RPG or a combat-heavy game on the platform, you've definitely seen them—those little green (or red) bars floating above a player's or an NPC's head that shrink as they take damage. It's way more intuitive than making players check a leaderboard or a static UI at the bottom of the screen just to see if they're winning a fight.
In this guide, we're going to walk through how to set one up from scratch. We aren't just going to slap a green box on a character; we'll talk about how to make it look good, how to make it move smoothly, and how to ensure it doesn't break your game's performance.
Why Use a Billboard GUI?
Before we dive into the "how," let's talk about the "why." Roblox offers a few different ways to show UI, but for health bars, the BillboardGui is king. Unlike a ScreenGui, which stays stuck to your monitor regardless of where you look, a Billboard GUI exists in the 3D world. It "points" toward the camera, so it's always readable, but it stays attached to a specific part—usually the Head or the HumanoidRootPart of a character.
It gives players that immediate spatial awareness. If you see five enemies charging at you, you can tell at a glance which one is the weakest. It adds a layer of strategy that a flat 2D overlay just can't match.
Setting Up the Hierarchy
First things first, you need to get your UI structure right. If you don't organize this correctly, your scripts are going to have a hard time finding the pieces they need to move.
Start by creating a BillboardGui. You can put this in StarterGui for testing, but eventually, you'll likely want it inside a folder in ServerStorage or ReplicatedStorage so you can clone it onto NPCs or players as they spawn.
Inside that BillboardGui, you'll want a main container. I usually call this "Background." Underneath that, you need the actual "HealthBar."
Here is the secret sauce: the Background should be the full width you want the bar to be (maybe colored dark red or grey), and the HealthBar should be a child of that background. Why? Because if the HealthBar's size is set to {1, 0}, {1, 0}, it will perfectly fill the background. When we change the health, we only have to change the X-scale of the HealthBar from 1 (100% health) to 0 (0% health).
Scale vs. Offset: Don't Make This Mistake
If there's one thing that trips up new developers, it's the difference between Scale and Offset. If you use Offset to size your roblox billboard gui health bar, it might look perfect when you're standing right next to the NPC. But as you walk away, that health bar is going to stay the same number of pixels wide. Eventually, it'll be bigger than the NPC themselves!
Always use Scale. Setting the size to something like {4, 0}, {0.5, 0} ensures the bar stays proportional to the world around it. It looks like a physical object in the game rather than a sticker on your screen.
Making the Bar Actually Work
Now for the part that actually makes it functional: the scripting. You don't need to be a coding wizard here, but you do need to understand how the Humanoid works in Roblox. Every character has a Humanoid object, and that object has two very important properties: Health and MaxHealth.
You'll want a script (usually a LocalScript if you want it to be super smooth) that listens for changes. The HealthChanged event is your best friend here. Instead of checking the health every single frame—which is a waste of processing power—you only update the bar when the health actually moves.
A simple logic flow looks like this: 1. Wait for the character to spawn. 2. Find the Humanoid. 3. Every time HealthChanged fires, calculate Humanoid.Health / Humanoid.MaxHealth. 4. Set the X-scale of your green bar to that result.
Adding Some Polish with TweenService
If you just snap the bar to a new size, it looks a bit "pointy" and cheap. To get that high-quality feel, you should use TweenService. This allows the bar to slide from one health value to another smoothly.
When the player takes damage, the bar shouldn't just vanish; it should shrink over maybe 0.2 seconds. It's a tiny change, but it makes the combat feel much more reactive. It also gives the player a split second to process exactly how much damage they just took.
Handling Visibility and Distance
Let's be real: you don't always want every health bar on the map visible at the same time. If there are 50 NPCs in a village, seeing 50 floating bars will clutter the screen and look like a mess.
The BillboardGui has a property called MaxDistance. Use it! Setting this to something like 50 or 100 studs ensures that you only see health bars for things you're actually interacting with.
You might also want to toggle the AlwaysOnTop property. If it's off, the health bar will be hidden behind walls and trees. If it's on, players can see the health bar through solid objects. This depends entirely on the type of game you're making. For a competitive shooter, you probably want it off so people can't use health bars as a "wallhack." For a co-op raid boss, you definitely want it on so everyone knows where the boss is.
Performance Considerations
While a single roblox billboard gui health bar isn't going to lag a computer, having hundreds of them running individual scripts can start to add up, especially on mobile devices.
If you're making a game with tons of units (like a tower defense or an RTS), consider using a "Single Script" architecture. Instead of putting a script inside every single health bar, have one central script that manages all of them. This is a bit more advanced, but it's the "pro" way to do things. You can keep a list of all active health bars and update them in a loop or via a centralized event handler.
Customizing the Look
Don't stick with the default white box. You can make your health bar stand out by using UIGradient to give the bar a nice color shift—maybe it's bright green at full health and turns dark orange as it gets lower. You can also add a UIStroke to give it a nice black outline, which helps it pop against bright backgrounds like a sunny sky or a snowy field.
Some developers even add a text label above the bar to show the character's name or level. Since the BillboardGui is already there, adding a text label is easy. Just make sure you manage the layout so the text doesn't overlap with the bar itself.
Wrapping Things Up
Building a roblox billboard gui health bar is a fantastic project because it touches on so many core parts of Roblox development: UI design, hierarchy, scripting, and optimization. Once you get the hang of it, you can use these same principles for all sorts of things—floating nametags, quest markers, or even interaction prompts like "Press E to Talk."
It's these little visual cues that bridge the gap between a "prototype" and a "real game." So, go ahead and experiment with different colors, tweening styles, and distances. Your players will definitely appreciate the extra clarity during a heated battle!