If you're trying to build a survival game or an RPG, you've probably realized that a roblox custom stamina bar script is one of those essential pieces of code that pulls everything together. It's one thing to have a character run around, but it's another thing entirely to give players that "oh no" moment when their energy bar hits zero right as a monster is chasing them. Creating a custom bar instead of using the default Roblox health bar style gives your game a much more polished, unique feel.
Setting this up isn't as hard as it might seem. You don't need to be a math genius or have years of Luau experience to get a functional, good-looking system going. We're going to walk through how to build the UI, write the script logic, and make sure it actually feels responsive when you're playing.
Getting the UI Ready
Before we even touch a line of code, we need something to look at. You can't really have a stamina bar without the actual "bar" part. In Roblox Studio, you'll want to head over to the StarterGui and insert a ScreenGui. Let's name it something simple like StaminaGui.
Inside that, you'll want a Frame to act as the background. This is the "empty" part of the bar. Make it a dark color, maybe a deep gray or black with some transparency. Then, inside that frame, add another frame—this will be the actual "fill." Let's call the background BarBackground and the fill StaminaFill.
A little tip for the StaminaFill: set its size to {1, 0}, {1, 0} so it perfectly fills the background. When we eventually script it, we'll be changing the X-scale of this bar from 1 (full) down to 0 (empty). If you want to get fancy, you can add a UICorner to both frames to give them those nice rounded edges that everyone loves these days.
The Logic Behind the Script
Now for the fun part. We need a LocalScript to handle the heavy lifting. I usually put this script directly inside the StaminaGui. The reason we use a LocalScript is that stamina is mostly a visual thing that reacts to the player's input instantly. While you might want server-side checks later for competitive games to prevent cheating, starting with a LocalScript is the way to go for the feel and responsiveness.
The core of a roblox custom stamina bar script revolves around three things: how much stamina you have, how fast it drains when you run, and how fast it grows back when you're chilling.
Setting Up Variables
First, we need to define our variables. We'll need the UserInputService to detect when the player is holding down the Shift key, and RunService to handle the frame-by-frame updates.
```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.BarBackground.StaminaFill local maxStamina = 100 local currentStamina = 100 local drainRate = 0.5 local regenRate = 0.3 local isSprinting = false ```
I like to keep the drainRate and regenRate as variables at the top so I can easily tweak them during playtesting. If 0.5 feels too fast, you can just bump it down to 0.2 without hunting through lines of code later.
Making It Move
We need to listen for when the player presses the Left Shift key. This is the universal "sprint" button in basically every Roblox game ever made.
```lua UIS.InputBegan:Connect(function(input, processed) if processed then return end if input.KeyCode == Enum.KeyCode.LeftShift then isSprinting = true humanoid.WalkSpeed = 24 end end)
UIS.InputEnded:Connect(function(input) if input.KeyCode == Enum.KeyCode.LeftShift then isSprinting = false humanoid.WalkSpeed = 16 end end) ```
This part is pretty straightforward. When Shift is held, we set a flag and speed up the character. When it's released, we slow them back down. But wait, we haven't actually linked this to the stamina yet. If we left it like this, the player could sprint forever, which kind of defeats the point of having a stamina bar.
Connecting the Bar to the Movement
This is where RunService.Heartbeat comes in. We want the script to check every single frame: "Is the player sprinting? Do they have stamina left?"
Inside the Heartbeat loop, we'll calculate the new stamina level. If they are sprinting and moving, we drop the stamina. If they aren't, we raise it back up—but we have to make sure it doesn't go above the maxStamina or below zero.
```lua RunService.Heartbeat:Connect(function() -- Check if the player is actually moving while sprinting if isSprinting and humanoid.MoveDirection.Magnitude > 0 and currentStamina > 0 then currentStamina = math.max(0, currentStamina - drainRate) else currentStamina = math.min(maxStamina, currentStamina + regenRate) end
-- If stamina hits 0, force them to stop sprinting if currentStamina <= 0 then humanoid.WalkSpeed = 16 end -- Update the UI local staminaPercent = currentStamina / maxStamina staminaBar.Size = UDim2.new(staminaPercent, 0, 1, 0) end) ```
The humanoid.MoveDirection.Magnitude > 0 check is actually really important. Without it, the player would lose stamina just by holding Shift while standing perfectly still. That's always a bit annoying in games, so it's better to only drain it when they're actually covering ground.
Adding Some Polish
Right now, the bar just "snaps" to its new size. It works, but it's a bit stiff. If you want your roblox custom stamina bar script to look professional, you should use TweenService for the UI changes. Instead of setting the size directly, you can smoothly transition it.
Another cool trick is changing the color of the bar as it gets low. You can use Color3.fromRGB to switch from a healthy green to an urgent red when the stamina drops below 20%. It's a small visual cue that helps players stay immersed without having to stare directly at the UI the whole time.
You might also want to consider a "cooldown" period. If the player completely exhausts their stamina, maybe they can't sprint again until the bar is at least 20% full. This prevents that weird jittery movement where players tap Shift repeatedly to move slightly faster while at zero stamina.
Common Issues to Watch For
Sometimes, the script might error out when the player dies and respawns. This usually happens because the character and humanoid variables are still pointing to the old, dead character model. To fix this, you can wrap your code in a function that re-initializes whenever player.CharacterAdded fires. It's a bit of extra work, but it saves you from the bar breaking every time someone falls off a cliff.
Also, keep an eye on your UI constraints. If you're using Offset instead of Scale for your bar size, it might look huge on a phone and tiny on a 4K monitor. Always try to use Scale (the first and third numbers in a UDim2) so the bar stays proportional to the screen size.
Why Custom Bars Are Better
Using a roblox custom stamina bar script isn't just about functionality; it's about the vibe. The default Roblox tools are great for prototyping, but a custom bar lets you match the aesthetic of your game. Whether you want a thin, minimalist line at the bottom of the screen or a chunky, stylized gauge next to the player's health, doing it yourself gives you total control.
It's honestly one of the most rewarding "little" things to script. Once you see that bar smoothly sliding back and forth as you run around your map, the whole project starts feeling like a real game. It adds a layer of strategy to movement, making players think about when to sprint and when to save their energy for a fight.
Anyway, that's the gist of it. It's a simple loop of checking input, adjusting a value, and updating a frame's size. Once you have the basics down, you can start adding things like stamina potions, gear that reduces drain, or even different sprint speeds for different character classes. The sky's the limit once you have the foundation built!