If you're trying to figure out how to build a basic roblox starter gui service esp, you've probably realized that moving things from the 3D world onto a 2D screen is a bit more involved than just clicking a button. It's one of those projects that every aspiring scripter tackles at some point because it teaches you so much about how the game engine actually calculates what you see on your monitor. Honestly, it's a great way to wrap your head around coordinate systems and UI management.
The core idea behind using the StarterGui service for an ESP (Extra Sensory Perception) system is pretty straightforward. You want to display information—like a box, a name, or a health bar—over other players in the game. Since these are 2D elements, they need to live inside the player's UI folder. This is where StarterGui comes in, as it acts as the container that pushes those UI elements to every player who joins the game.
Why use StarterGui for this?
You might wonder why we don't just stick a BillboardGui into a player's head and call it a day. While that works for simple name tags, using the roblox starter gui service esp method with a ScreenGui gives you way more control. When you script everything to render on a 2D plane, you can customize the visuals much more easily. You aren't limited by the physical constraints of an object in the 3D space.
Plus, putting your logic in StarterPlayerScripts and having it interact with StarterGui keeps things organized. When a player joins, the game clones everything from StarterGui into their personal PlayerGui. This is where the magic happens. By scripting a local loop that looks at where other players are in the world, you can draw frames directly onto the screen that perfectly align with their 3D characters.
The logic behind the visuals
The biggest hurdle for most people is the math. Don't worry, you don't need a degree in trigonometry, but you do need to understand a specific function called WorldToViewportPoint. This is the secret sauce for any roblox starter gui service esp.
Essentially, this function takes a 3D position—like a player's Torso or HumanoidRootPart—and translates it into a 2D coordinate on your screen (X and Y). It also returns a boolean (true or false) that tells you if that point is actually on the screen. This is huge because you don't want your script trying to draw a box for a player who is standing directly behind you. That would just be a waste of resources and might cause some weird visual glitches.
Setting up the script
To get started, you'll usually want to place a LocalScript inside StarterPlayerScripts. You could put it in StarterGui too, but StarterPlayerScripts is generally a cleaner place for logic that doesn't strictly represent a single UI button.
First, you'll need to define the services you're using. You'll definitely need RunService, Players, and of course, the UserInputService if you want to toggle the ESP on and off with a keybind. RunService.RenderStepped is going to be your best friend here. Unlike a standard while wait() do loop, RenderStepped runs every single frame right before the frame is rendered. This ensures that the ESP boxes don't "jitter" or lag behind the players as they move across your screen.
Creating the UI elements dynamically
When you're working with a roblox starter gui service esp, you have two choices: you can either create the UI elements manually in the Studio editor and clone them, or you can create them entirely through code. Most experienced scripters prefer creating them through code using Instance.new("Frame").
It sounds tedious, but it's actually much more flexible. You can set the Size, BackgroundColor3, and BorderSizePixel all within your script. For a basic ESP, you're looking at a thin frame with a transparent background and a bright border (like neon green or red). You'll also want to make sure the ZIndex is high enough so it draws on top of other UI elements, but that's usually not an issue unless your game has a very crowded HUD.
Filtering the players
One thing you'll quickly notice is that you probably don't want an ESP box showing up over your own character. That would be pretty distracting. In your loop, you'll need to add a simple check: if player == LocalPlayer then continue end.
Similarly, if you're making a team-based game, you might want to change the color of the box based on the player's team. Using player.TeamColor makes this easy. You can just grab that color and apply it to the BorderColor3 of your frame. It's these small touches that make a roblox starter gui service esp feel professional rather than like something thrown together in five minutes.
Handling performance and optimization
I can't stress this enough: performance is king. If you're in a server with 50 players and your script is doing heavy calculations and creating/destroying objects every frame, the game is going to lag.
Instead of creating a new frame every frame (which is a nightmare for memory), you should create one frame per player when they join and just toggle its Visible property. If the WorldToViewportPoint says the player is on-screen, set Visible to true and update the position. If they're off-screen or too far away, set Visible to false. This "pooling" of UI elements keeps the game running smoothly even on lower-end mobile devices or older PCs.
Dealing with distance
Another cool feature to add to your roblox starter gui service esp is a distance check. Not only does it look cleaner, but it's also practical. You can calculate the distance between your character and the target player using .Magnitude.
If the player is 500 studs away, maybe you don't want to show a big bulky box. You could scale the box down as they get further away, or simply hide it entirely if they're across the map. This prevents your screen from becoming a cluttered mess of neon boxes when you're looking toward a crowded area.
Common pitfalls to avoid
One of the most annoying things you might encounter is the "offset" issue. Roblox UI coordinates start from the top-left, but sometimes the top bar (where the Roblox icon and chat button live) can throw off your calculations if you aren't careful. Luckily, WorldToViewportPoint handles most of this, but if you notice your boxes are slightly lower than the actual players, check if you're accounting for the GuiService:GetGuiInset() value.
Also, remember that players can reset or leave the game. Your script needs to be robust enough to handle a player's character disappearing. Always check if the character and the HumanoidRootPart actually exist before you try to get their position. A simple if character and character:FindFirstChild("HumanoidRootPart") then will save you from a constant stream of errors in your output window.
Taking it a step further
Once you've got the basic box working using the roblox starter gui service esp method, you can start adding the "fancy" stuff. Some people like to add health bars that change from green to red as a player takes damage. Others add the player's name and the weapon they're currently holding.
You can even use Drawing.new if you want to go beyond StarterGui, but for most people starting out, sticking to the standard UI service is much more intuitive because it works exactly like the buttons and menus you're already used to building.
Final thoughts on the process
Building a roblox starter gui service esp is basically a rite of passage for Roblox developers. It forces you to learn about LocalScripts, the difference between client and server, and how to manipulate the 2D workspace to reflect the 3D world.
Just remember to keep your code clean and always think about the player's experience. You want a tool that provides information without being an eyesore. Experiment with different transparency levels and border thicknesses until you find a style that fits the vibe of your game. It's all about trial and error, but once you see those boxes perfectly tracking players across the map, it's a really satisfying feeling. Keep at it, and don't be afraid to break things—that's usually how you learn the most!