Roblox anti cheat script fly detection is honestly one of the most frustrating yet essential things a developer has to figure out if they want their game to stay fair. There is nothing that kills the vibe of a competitive or roleplay game faster than some random person zooming across the sky, skipping all the hard work you put into your map's layout. If you've spent weeks building an intricate obstacle course or a balanced simulator, watching someone bypass it all with a simple exploit script feels like a personal insult. But here's the thing: detecting flight isn't as straightforward as just checking if a player is in the air.
If it were easy, every game would be exploit-free by now. The reality is that Roblox's physics engine is a bit of a chaotic mess sometimes. Players lag, they get stuck in walls, or they get "flung" by weird physics glitches that make the engine think they're traveling at Mach 5. If your detection is too sensitive, you end up kicking your actual players just because their internet dipped for a second. If it's too loose, the exploiters will literally walk all over you—or fly over you, I guess.
Why Fly Hacks are Such a Headache
Exploiters usually pull off flight by manipulating a few specific things on the client side. They might use a BodyVelocity object, a BodyGyro, or they might just be constantly overriding their character's CFrame to move them upward and forward. Since Roblox gives the client (the player's computer) a lot of "network ownership" over their own character to make the game feel responsive, the server often just believes whatever the client says.
"Hey server, I'm now 500 feet in the air," says the exploiter's computer. And the server, being a trusting soul, says, "Cool, I'll update your position for everyone else to see." That's where your roblox anti cheat script fly detection needs to step in and be the "skeptical parent" of the operation.
The Basic Logic: Raycasting is Your Best Friend
The most common way people try to detect flying is by checking the FloorMaterial property of a player's humanoid. If the material is "Air" for more than a few seconds, they must be flying, right? Well, not exactly. What if they're falling off a cliff? What if they're jumping on a trampoline? What if they're just lagging while standing on a moving platform?
Instead of relying on the built-in material check, most experienced devs use Raycasting. Think of a raycast like an invisible laser beam shot from the player's feet straight down toward the ground.
If that laser doesn't hit anything within a reasonable distance (say, 10 or 15 studs) for a prolonged period, then you've got a red flag. But even then, you can't just slap a Player:Kick() on that and call it a day. You have to account for the "state" of the character. Is the player currently in a "Falling" state? Have they been in that state for more than 5 seconds? Are they moving upwards while in that state? These are the questions your script needs to ask.
Avoiding the "False Positive" Nightmare
This is the part that keeps developers up at night. Imagine a player with a really bad ping. On their screen, they're just walking normally, but to the server, their position hasn't updated in three seconds. When the connection finally catches up, the player "teleports" to their new spot. If your anti-cheat sees that sudden jump in height or distance, it might flag it as a fly hack or a teleport hack.
To stop yourself from accidentally banning your own fan base, you need to implement a "violation level" or a "buffer" system. Instead of kicking immediately, your script should: 1. Flag the behavior: "Okay, this guy has been in the air for a while." 2. Add to a counter: Increment a "sus" value. 3. Check for physics exceptions: Are they sitting in a seat? Are they near a part tagged as a "jump pad"? 4. Take action: Only when that counter hits a certain threshold do you actually do something.
Sometimes, the best "punishment" isn't even a kick. It's often better to just teleport the player back to their last known "good" position on the ground. It ruins the exploiter's fun without ruining a legitimate player's session if the script made a mistake.
Server-Side vs. Client-Side Detection
You might be tempted to put your roblox anti cheat script fly detection inside a LocalScript because it's easier to access the player's input and immediate movement. Don't do this. Well, you can do it for some things, but never rely on it.
Exploiters have full control over the client. They can see your LocalScripts, they can disable them, and they can even change the code inside them while the game is running. Anything important must happen on the server (a Script inside ServerScriptService).
The server should be the one running a loop—maybe every 0.5 or 1 second—checking the positions of all players. It calculates the distance between where they were a second ago and where they are now. If that distance is physically impossible for a walking human, you know something is up.
The Magnitude Check
A big part of fly detection is actually "speed detection." Most fly hacks involve moving faster than the default walk speed. By checking the Magnitude of the player's velocity (specifically on the Y-axis for flying), you can catch a lot of the amateur exploiters.
If the player's Velocity.Y is consistently 50 for more than two seconds without a corresponding "Launch" or "Explosion" event occurring in the game world, that's a pretty solid indicator that they're using a fly script.
Why You Shouldn't Just Copy-Paste a Script
It's really tempting to go to the Roblox Toolbox or a random DevForum post and just copy-paste a "Super Ultimate Anti-Cheat 2024" script. The problem is that exploit creators have access to those same scripts. They download them, read the code, and then write their exploits specifically to bypass those exact checks.
A custom-built roblox anti cheat script fly detection system is way more effective because it's unique to your game's mechanics. If your game has low gravity, your anti-cheat needs to know that. If your game has a double-jump mechanic, a generic anti-cheat will probably break it. By building your own, you can tailor the "strictness" to exactly what your gameplay requires.
The "Cat and Mouse" Game
At the end of the day, you have to accept that anti-cheat is a game of cat and mouse. You'll update your script, and then a week later, someone will find a way around it. Maybe they'll figure out that if they toggle their fly hack on and off every 0.2 seconds, they can bypass your "time-in-air" check.
The goal isn't necessarily to make a 100% unhackable game—that doesn't really exist. The goal is to make it so annoying and so difficult to exploit in your game that the exploiters just give up and go find an easier target.
Final Thoughts for Devs
When you're writing your roblox anti cheat script fly detection, keep it lightweight. You don't want a script that's doing 50 complex math equations every frame for every player in a 50-player server. That's how you get server lag, which—ironically—makes it easier for exploiters to hide their movements.
Keep your checks simple: * Are they significantly above the ground? * Have they been there too long? * Are they moving in a way the game doesn't normally allow? * Are they currently "falling" but moving upward?
If you can answer those four questions reliably, you're already doing better than 90% of the games on the platform. Just remember to be fair, test your script with a high-ping friend, and always keep a log of who gets flagged so you can check for false positives later.
Building a solid anti-cheat is a learning process, but it's one of the most rewarding skills you can pick up as a Roblox dev. It protects your community and keeps the competitive integrity of your world intact. Happy coding, and may your "sus" counters always be accurate!