Getting a solid roblox stamina bar script gui working is one of those small details that makes your game feel way more polished and professional. If you've ever played a survival or fighting game where you can just sprint forever, you know it feels a bit broken. Adding a stamina system forces players to think about when to push their luck and when to back off and recover. It adds a layer of strategy that keeps the gameplay loop interesting.
The cool thing about Roblox is that you can build this from scratch pretty easily once you understand how the UserInputService and basic GUI manipulation work together. You don't need to be a coding wizard to get this running, but you do need a bit of patience to get the "feel" of the bar just right. Let's walk through how to set this up so it looks good and actually functions without lagging your game out.
Setting Up the Visuals in StarterGui
Before we even touch a line of code, we need something to look at. You can't have a script without a GUI to control, right? Head over to your Explorer window and find StarterGui. You'll want to add a ScreenGui first—let's just call it "StaminaGui."
Inside that, you're going to want two frames. The first one is your "Background" or "Container." This is the static part of the bar that stays the same size, usually a dark gray or black color with some transparency. Then, inside that container, add another frame and call it "Bar." This is the one we're actually going to animate. Give it a bright color like green or yellow.
Pro tip: set the "Bar" frame's size to {1, 0}, {1, 0} so it fills the container completely. When we start scripting, we'll be changing the X-scale of this bar to show how much energy the player has left. If the scale is 1, they're full. If it's 0.5, they're at half. It's a super simple way to handle health or stamina bars without doing complex math.
The Logic Behind the Script
Now for the fun part: making it work. You'll want to put a LocalScript inside your ScreenGui. We use a LocalScript because the UI is client-side—it's happening on the player's screen, and we want it to react instantly to their key presses.
The basic logic goes like this: we need to keep track of a "Stamina" variable. When the player holds down the Shift key, we check if they are moving. If they are, we increase their WalkSpeed and slowly subtract from that stamina variable. When they let go of Shift, or if the stamina hits zero, we set their speed back to normal and start the regeneration process.
I've seen people try to do this with simple wait() loops, but that usually looks choppy. To make it feel modern, we're going to use TweenService. This service is a lifesaver because it automatically calculates the "in-between" frames, making the bar slide smoothly instead of just snapping to a new size.
Writing the Core Script
In your LocalScript, you'll want to start by defining the services you need. You'll definitely need UserInputService for the key detection and TweenService for the bar movement. You'll also need to reference the player's character to change their speed.
Let's talk about variables for a second. Don't just hardcode numbers. Set up some variables at the top like maxStamina = 100, staminaRegenRate = 1, and staminaDepleteRate = 2. This makes it way easier to balance your game later. If you find out players are running for too long, you can just change one number at the top of the script instead of hunting through fifty lines of code.
Here is where the "magic" happens: you need a loop that runs constantly. Using RunService.Heartbeat is usually better than a while true do loop because it syncs up with the game's frame rate. Every frame, you check: Is the player sprinting? If yes, subtract. If no, is their stamina less than the max? Then add.
Handling the Sprint Input
The UserInputService has two main events we care about: InputBegan and InputEnded. When the player hits LeftShift, we set a boolean variable—let's call it isSprinting—to true. When they let go, we set it to false.
But wait, there's a catch! You don't want the player to "sprint" while they are standing still. That would be a bit silly—they'd be losing stamina just for holding a key while chatting. You should add a check to see if the character's MoveDirection.Magnitude is greater than zero. This ensures they only lose energy when they are actually moving their feet.
Also, don't forget the "exhaustion" state. If the stamina hits zero, you should probably force the player to stop sprinting and maybe even wait until the bar is at 20% or 30% before they can sprint again. This prevents that annoying "stutter-stepping" where players spam the shift key when they're out of breath.
Making the GUI Look Professional
Once the script is functional, it's time to make it look like it actually belongs in a real game. A plain green bar is fine for a prototype, but you can do better. Try adding a UIStroke to the container to give it a nice border. You can also add a UIGradient to the bar itself to give it a bit of a color shift—maybe it turns from green to red as it gets lower.
Another thing that really helps is using UIAspectRatioConstraint. This ensures that your stamina bar doesn't look all stretched out and weird if someone is playing on a super-wide monitor or a tiny phone screen. Roblox is played on everything from high-end PCs to old iPhones, so your roblox stamina bar script gui needs to be responsive.
Troubleshooting Common Issues
Usually, when someone says their stamina bar isn't working, it's because of one of two things. Either they aren't referencing the character correctly, or they are trying to change the WalkSpeed from a script that doesn't have the right permissions.
Since the character can respawn, you need to make sure your script updates the reference to the character every time they die. If you only grab the character once when the game starts, the script will break as soon as the player falls into the void or gets reset. You can handle this by using the Player.CharacterAdded event to refresh your variables.
Another common headache is "flickering." This happens when your regeneration and depletion logic are fighting each other. Make sure your "if" statements are airtight—if the player is sprinting, they should not be regenerating stamina at the same time. It sounds obvious, but it's a mistake that happens more often than you'd think.
Taking It a Step Further
If you really want to get fancy with your roblox stamina bar script gui, you could add sounds. Maybe a heavy breathing sound effect plays when the stamina is below 15%, or a little "click" sound happens when the bar is fully recharged. These audio cues are huge for immersion.
You could also link the stamina to other actions. Maybe jumping takes away a chunk of stamina, or swinging a sword costs energy. Since you've already built the core GUI and variable system, adding these features is just a matter of adding a few more lines of code to your existing logic.
Final Thoughts on Implementation
Building a custom stamina system is a great way to learn how the different parts of Roblox Studio talk to each other. You've got the UI for the visuals, the LocalScript for the logic, and the Character properties for the physics. It's a perfect "level up" project for anyone moving past basic tutorials.
Just remember to keep it simple at first. Get the bar moving, get the speed changing, and then worry about the fancy gradients and sound effects later. Once you have the foundation, you can tweak the variables until the movement feels exactly how you want it. It's all about that "game feel," and a smooth stamina bar is a massive part of that. Happy developing!