Roblox custom stamina bar script projects are usually the first thing developers look for when they want to move past the "basic" feel of a default baseplate game. If you've ever played a survival horror game or a high-stakes obstacle course, you know how much a simple green bar at the bottom of the screen adds to the tension. Without it, players can just hold down the Shift key and sprint forever, which kind of ruins the balance of your game design.
But creating one isn't just about making a bar get smaller. It's about the "feel" of the movement—the way it drains when you're pushing your character and how it slowly creeps back up when you stop to catch your breath. Honestly, it's one of those small details that separates a hobbyist project from something that feels professionally made. Let's break down how to actually build one that doesn't just work, but looks great too.
Why You Shouldn't Just Use the Default
Sure, you could probably find a generic kit in the Toolbox, but those are often bloated with weird code or don't fit the vibe of your UI. When you write your own roblox custom stamina bar script, you have total control. Do you want it to flash red when it's empty? Do you want the character to walk slower for a few seconds if they completely exhaust themselves? You can't easily do that with a "plug-and-play" model you found in two seconds.
Plus, learning the logic behind a stamina system is a fantastic way to understand how LocalScripts communicate with the player's character. It's a foundational skill. Once you get this down, you can apply the same logic to mana bars, oxygen levels for swimming, or even a "fear" meter.
Setting Up the Visuals (The GUI)
Before we even touch a line of code, we need something to look at. In Roblox Studio, head over to the StarterGui and create a ScreenGui. Inside that, you'll want a Frame to act as the background (let's call it StaminaBackground). This is usually a dark, semi-transparent rectangle.
Inside that background frame, add another frame and call it StaminaBar. This is the part that will actually move. Give it a bright color—green is the classic choice, but maybe a neon blue if you're going for a sci-fi look.
A quick tip: Make sure you set the StaminaBar size using Scale rather than Offset. If you use Offset, your bar might look huge on a phone and tiny on a 4K monitor. Scale ensures it stays relative to the background frame regardless of the device.
The Core Logic
Now for the fun part. We need a LocalScript to handle the heavy lifting. You should put this script inside your StaminaBackground frame or inside StarterPlayerScripts. I personally prefer keeping it near the UI it's controlling so I don't lose track of it later.
We're going to need a few variables to start. We need to define the player, their character, and the "Humanoid" object, because that's where the WalkSpeed lives. We also need to define our constants: MaxStamina, CurrentStamina, DrainRate, and RegenRate.
```lua local UIS = game:GetService("UserInputService") local RunService = game:GetService("RunService")
local player = game.Players.LocalPlayer local character = player.Character or player.CharacterAdded:Wait() local humanoid = character:WaitForChild("Humanoid")
local staminaBar = script.Parent.StaminaBar -- Adjust this path to your bar
local maxStamina = 100 local currentStamina = 100 local sprintSpeed = 24 local normalSpeed = 16 local isSprinting = false ```
The logic is pretty straightforward: every frame, we check if the player is holding the Shift key and moving. If they are, we subtract from currentStamina. If they aren't, we add to it—up to the maximum.
Making it Smooth with RunService
A lot of beginners use a while true do wait() end loop for this, but that's a bit old-school and can feel stuttery. Instead, use RunService.Heartbeat. This event fires every single frame, making the bar's movement look buttery smooth.
Inside the Heartbeat function, you'll calculate the new stamina value. But don't forget to "clamp" the value. Clamping is just a fancy way of saying "don't let this number go below zero or above 100." Roblox has a built-in function for this: math.clamp(). It saves you from writing a bunch of messy if statements.
```lua RunService.Heartbeat:Connect(function(deltaTime) if isSprinting and humanoid.MoveDirection.Magnitude > 0 and currentStamina > 0 then currentStamina = math.max(0, currentStamina - (10 * deltaTime)) humanoid.WalkSpeed = sprintSpeed else currentStamina = math.min(maxStamina, currentStamina + (5 * deltaTime)) if currentStamina <= 0 or not isSprinting then humanoid.WalkSpeed = normalSpeed end end
-- Update the UI staminaBar.Size = UDim2.fromScale(currentStamina / maxStamina, 1) end) ```
Handling Input
To actually trigger the sprint, we use UserInputService. You'll want to listen for InputBegan to start sprinting and InputEnded to stop. It's important to check if the player is typing in the chat, though! You don't want their character to start sprinting just because they typed a capital "S" in a message. You can do this by checking the gameProcessedEvent parameter.
```lua UIS.InputBegan:Connect(function(input, processed) if processed then return end if input.KeyCode == Enum.KeyCode.LeftShift then isSprinting = true end end)
UIS.InputEnded:Connect(function(input) if input.KeyCode == Enum.KeyCode.LeftShift then isSprinting = false end end) ```
Adding Visual Polish (TweenService)
If you want to take your roblox custom stamina bar script to the next level, you should look into TweenService. Right now, the bar just snaps to its new size. While it's fast, it can look a bit rigid.
By using a "Tween," you can make the bar size transition smoothly. However, since we're updating the bar every frame in a Heartbeat loop, a full Tween might be overkill. A simpler trick is to use Lerp (Linear Interpolation). It's basically a way to say "move this value 10% closer to the target every frame." It creates a nice "lagging" effect that feels very organic.
Another cool trick is to change the color of the bar as it gets lower. You can use Color3.fromHSV() to transition from a healthy green to a warning red. It's a tiny bit of math, but it makes the UI feel alive.
Common Mistakes to Avoid
One thing I see all the time is developers forgetting to check if the player is actually moving. If you only check if Shift is held down, the player will drain all their stamina while standing perfectly still. That's just annoying for the player. Always check humanoid.MoveDirection.Magnitude > 0 to ensure they're actually running.
Another big one is performance. You don't want to update the UI text or heavy assets every single frame if the stamina hasn't actually changed. While modern PCs can handle it, it's good practice to only run the UI update code if currentStamina has shifted since the last frame.
Security Considerations
Since we're doing this in a LocalScript, technically a cheater could modify their local script to give themselves infinite stamina. For a casual hangout game, who cares? But if you're making a competitive game where stamina is a major mechanic, you'll eventually want to move the actual math to a Script on the server.
The server would keep track of the "real" stamina and the LocalScript would just be responsible for the pretty visuals. It's more complex to set up because you have to deal with RemoteEvents, but it's the only way to keep things fair.
Wrapping It Up
Building a roblox custom stamina bar script is a great "Level 2" scripting project. It moves you away from simple "Touch to kill" scripts and into the territory of managing game states and player resources.
Don't be afraid to experiment with the numbers. Maybe your game feels better with a really fast drain and a really fast regen, like an action-RPG. Or maybe you want a very slow, grueling stamina burn for a hardcore survival sim. The beauty of writing it yourself is that you're the one who gets to decide how the game feels to play.
Once you've got the bar working, try adding a little sound effect—like a heavy breathing loop—that triggers when the stamina hits 10%. It's those little layers of feedback that turn a simple script into an immersive experience. Happy scripting!