If you're looking to spice up your game mechanics, learning how to build a roblox custom stamina system script from scratch is a total game-changer. Most new developers just let players run around at full speed forever, but if you're making a horror game, a battle royale, or even a realistic roleplay map, you quickly realize that infinite sprinting kills the tension. You want your players to feel that panic when their lungs are burning and a monster is right behind them, or that tactical trade-off in a fight where they have to decide between swinging a sword and saving enough energy to dodge.
Why you need a custom system
The default Roblox character controller is great for basics, but it doesn't give you much control over physical limits. When you write your own roblox custom stamina system script, you're taking back that control. You get to decide exactly how fast people lose energy, how long it takes to recover, and even what happens when they hit zero.
Think about games like Dark Souls or Deepwoken. Stamina isn't just a bar that goes down; it's a resource that dictates every move the player makes. If you just use a basic script you found in the Toolbox, it'll probably work, but it won't feel "right" for your specific game. Writing it yourself allows you to tweak the "weight" of the movement. Maybe you want the regeneration to pause for a second after a sprint, or maybe you want the player's screen to blur when they're exhausted. That's the stuff that makes a game feel professional.
Setting up the visual interface
Before we even touch the code, we need something for the player to look at. Nobody likes guessing how much energy they have left. You'll want to head into the StarterGui and create a basic ScreenGui. Inside that, I usually toss in a Frame to act as the background (maybe a dark gray or black with some transparency) and then another Frame inside that one to act as the actual bar (usually a bright green or blue).
It's a good idea to name these clearly—something like "StaminaBar" and "Fill." Pro tip: set the Fill frame's size using Scale rather than Offset. If you use Scale, it'll look the same on a massive 4K monitor as it does on a tiny phone screen. If you use Offset, your stamina bar might take up half the screen for mobile players, which is a total nightmare for UX.
Writing the core logic
The meat of the roblox custom stamina system script usually lives in a LocalScript inside StarterPlayerScripts or even inside the UI itself. You're going to be using the UserInputService to check when the player is holding down the Shift key (or whatever button you want for sprinting).
The logic is pretty straightforward: 1. Check if the player is moving and holding the sprint key. 2. If they are, increase their WalkSpeed and slowly subtract from a stamina variable. 3. If they aren't sprinting, or if they're standing still, start adding to that stamina variable until it hits the max. 4. Make sure to cap the stamina so it doesn't go below zero or above a hundred.
One thing people often forget is checking if the player is actually moving. There's nothing weirder than a player holding Shift while standing still and watching their stamina bar drain into nothingness. You can check the MoveDirection property of the character's Humanoid to make sure they're actually walking before you start penalizing their energy levels.
Handling the "Out of Breath" state
What happens when the bar hits zero? This is where you can get creative. Most people just set the WalkSpeed back to 16 (the default) and wait for it to recharge. But if you want to be mean—or realistic—you can drop their speed even lower, like to 8 or 10. This forces the player to actually manage their resources rather than just "redlining" the bar constantly.
You can also use a boolean variable called isExhausted. If stamina hits zero, set isExhausted to true and don't let them sprint again until the bar has recharged to at least 20% or 30%. This prevents that annoying "stutter-stepping" where players spam the shift key to get tiny bursts of speed while at 1% stamina.
Making it look smooth with TweenService
If you just set the bar's size directly in a loop, it's going to look choppy. It'll flicker and jump around, and it just feels "cheap." To fix this, you should use TweenService. Instead of saying "set size to X," you tell Roblox "smoothly transition the size to X over 0.2 seconds."
This makes the bar glide back and forth. It's a tiny detail, but it's one of those things that separates an amateur project from something that feels polished. You can also use tweens to change the color of the bar. Maybe it stays green most of the time, but as it drops below 25%, it turns bright red to warn the player they're about to run out of juice.
Thinking about the server-side
Here is where things get a bit tricky. A roblox custom stamina system script that runs entirely on the client (the player's computer) is super easy to exploit. A clever player can just open an injector, find your script, and change the "stamina" variable to 999,999. Suddenly, they have infinite sprint.
If your game is competitive, you'll eventually want to move some of this logic to the server. You can have the client send a "RemoteEvent" saying "Hey, I'm trying to sprint," and the server checks if they actually have the stamina to do it. However, doing everything on the server can cause lag, making the movement feel delayed. Most devs find a middle ground—let the client handle the visuals and the immediate speed change so it feels snappy, but have the server do "sanity checks" every second to make sure the player isn't moving faster than they should be.
Adding some extra "Juice"
Once the basic roblox custom stamina system script is working, you should start adding the "juice." This is the stuff that makes the mechanic feel immersive.
- Sound Effects: Add a heavy breathing sound loop that starts playing when stamina is below 20%. Increase the volume as it gets closer to zero.
- Camera Effects: Use a slight "Field of View" (FOV) change when sprinting. Increasing the FOV by 10 or 15 points makes the player feel like they're moving much faster than they actually are.
- Post-Processing: Add a slight blur or a vignette effect (darkening the edges of the screen) when the player is exhausted. It simulates that tunnel vision you get when you're physically wiped out.
Common pitfalls to avoid
I've seen a lot of people mess this up by putting the entire loop inside a while true do block without a proper wait time. If you don't include a task.wait(), you'll probably crash the player's game because the script is trying to run a million times a second.
Another big one is not cleaning up your connections. If a player dies and respawns, you need to make sure your script finds the new character and the new humanoid. If your script is still trying to change the WalkSpeed of the old, dead character, it just won't work, and you'll see a bunch of red errors in your output log. Using CharacterAdded:Connect() is the way to go here to ensure the script refreshes every time the player resets.
Wrapping it up
Creating a roblox custom stamina system script is one of those fundamental skills that really opens up what you can do as a designer. It's not just about stopping people from running; it's about creating a rhythm for your gameplay. Whether it's the frantic dash away from a killer or the careful management of energy in a sword fight, the stamina system is the heartbeat of your game's movement.
Don't be afraid to experiment with the numbers. There is no "correct" speed or depletion rate. Playtest your game, see how it feels, and tweak those variables until the movement feels exactly how you imagined it. Once you get the hang of it, you can even expand the system to include things like swimming stamina, climbing limits, or special abilities that consume a chunk of the bar at once. Happy coding!