Developing a solid roblox anti cheat script fly speed system is basically the first thing every creator needs to worry about if they want their game to survive more than five minutes on the front page. Let's be real, there is nothing that kills the vibe of a growing community faster than some random exploiter zooming across the map at Mach 5 or hovering over the objective where nobody can hit them. It makes the hard work you put into your level design feel totally pointless. If you've spent any time on the platform, you know the struggle—you're trying to build a balanced experience, and then someone uses a basic "Dex" or "Infinite Yield" command to bypass every rule you've set.
The core of the issue is that Roblox, by its very nature, gives the client (the player) a lot of control over their own character. This is great for making movement feel smooth and responsive, but it's a nightmare for security. Because the player's computer calculates where they are moving, a savvy exploiter can just tell the server, "Hey, I'm actually 500 studs in the air now," and the server often just shrugs and says, "Okay, cool." To fix this, we have to move the authority back to the server.
Why Speed and Fly Exploits Are So Common
The reason why we see so many people looking for a roblox anti cheat script fly speed fix is that these are the easiest things to modify in a local environment. Every character has a Humanoid object, and that object has a WalkSpeed property. On the client side, changing that number from 16 to 100 takes about two seconds of effort. Flying is slightly more complex but usually involves inserting a BodyVelocity or a BodyGyro into the character's HumanoidRootPart. Since the client has network ownership of their character, these physical changes replicate to everyone else unless the server specifically steps in to double-check the math.
It's a bit of an arms race. You build a wall, they find a ladder. You put barbed wire on the wall, they bring wire cutters. That's why a "set it and forget it" approach rarely works perfectly. You need a system that is flexible enough to catch the bad guys but smart enough not to punish the kid playing on a 10-year-old laptop with a laggy internet connection.
The Logic of Distance and Time
The most effective way to handle a roblox anti cheat script fly speed check is to look at the relationship between distance and time. We know how fast a player is supposed to be. If your game's default speed is 16, and a second passes, that player shouldn't be more than 16 or 17 studs away from where they were a second ago.
On the server, you can run a loop—usually using Task.wait() or connecting to the RunService.Heartbeat event—that periodically grabs the player's HumanoidRootPart.Position. You compare that to the position they were at during the last check. By using the .Magnitude property of the vector difference, you get a single number representing the distance traveled. If that number is way higher than it should be, you've caught a speeder.
Handling the "Fly" Factor
Flying is detected in a similar way, but with an extra layer of logic regarding the Y-axis (height). Most fly scripts work by negating gravity or constantly pushing the player upward. To catch this, your roblox anti cheat script fly speed logic needs to check if the player is "falling" but not actually losing altitude, or if they are suspended in the air for an unnatural amount of time without a platform beneath them.
A common trick is to use Raycasting. Every few ticks, the server can fire a ray straight down from the player's feet. If the ray doesn't hit anything for a long distance, and the player isn't in a "Falling" or "Jumping" state that makes sense, they might be flying. You have to be careful here, though. If your game has high-jump mechanics or airplanes, you need to whitelist those states so you don't accidentally kick your best players.
Don't Trust the Client
This is the golden rule of Roblox development. If you write a script and put it inside StarterPlayerScripts, an exploiter can just disable it or delete it. For a roblox anti cheat script fly speed system to actually work, the heavy lifting has to happen in ServerScriptService.
The server should be the one doing the calculations. The client shouldn't even know it's being watched. When the server detects an anomaly, it shouldn't ask the client for permission to reset them—it should just do it. However, you don't always want to jump straight to a ban.
Managing False Positives and Lag
One of the biggest headaches with a roblox anti cheat script fly speed system is lag. If a player's internet stutters, they might appear to "teleport" from the server's perspective. To the server, it looks like they moved 100 studs in 0.1 seconds. If your script is too aggressive, you'll end up kicking half your player base because their Wi-Fi skipped a beat.
Instead of an instant kick, many developers use a "rubber band" method. If the server thinks a player moved too fast, it just teleports them back to their last "valid" position. It's annoying for an exploiter because they can't get anywhere, but for a laggy player, it just feels like a minor glitch. You can also implement a "strike" system. One suspicious move? No big deal. Ten suspicious moves in ten seconds? Okay, now we have a problem.
The Importance of Buffers
When you're calculating the max distance a player can travel, always add a buffer. If the max speed is 16, maybe set the detection threshold to 22 or 25. This gives room for physics interactions, explosions that might launch a player, or just general engine jitter. It's better to let a very slight speed boost slide than to ruin the experience for everyone else with constant false detections.
Dealing with Teleports and Vehicles
If your game has legitimate teleports—like a "Return to Lobby" button or a map-travel system—your roblox anti cheat script fly speed logic needs to be aware of them. Before you move a player via script, you should set a flag or a variable on the server that tells the anti-cheat, "Hey, I just moved this guy, don't freak out." After a second or two, you can turn the check back on.
The same goes for vehicles. If a player jumps in a car that goes 100 MPH, your speed check is going to lose its mind. You'll need to check if the player is currently sitting in a VehicleSeat and adjust the speed thresholds accordingly. It's these little details that separate a clunky script from a professional-grade system.
Performance Considerations
Running a check on every single player 60 times a second can get heavy, especially if you have a 50-player server. To keep your roblox anti cheat script fly speed system optimized, you don't necessarily need to check every frame. Checking every 0.5 or 1 second is usually plenty. Most exploiters aren't going to be able to do much damage in a half-second window, and it drastically reduces the load on the server's CPU.
Also, try to avoid complex math where possible. Stick to simple magnitude checks and basic raycasts. Roblox's engine is pretty fast, but if you're doing hundreds of raycasts per second for every player, you're going to notice some frame drops.
Final Thoughts on Implementation
Building a roblox anti cheat script fly speed system is a constant learning process. You'll probably ship your first version, feel really proud of it, and then five minutes later see someone bypass it. Don't get discouraged! It's part of the game. The goal isn't necessarily to make a perfect, unhackable game (which is basically impossible), but to make it so difficult and annoying for exploiters that they just give up and go find an easier target.
Keep your code clean, keep your server-side checks robust, and always prioritize the experience of your legitimate players. If you can stop the most common fly and speed hacks without bothering the people who are just there to play, you've already won most of the battle. Happy developing, and may your servers stay exploiter-free!