If you're tired of exploiters ruining your game, building a solid roblox anti cheat script fly speed jump detection is probably your top priority right now. There is nothing more frustrating than spending hundreds of hours building a balanced map or a competitive round-based game, only to have some kid join and zip across the world at Mach 5 or hover over everyone like a budget superhero. It kills the vibe, drives away your legitimate players, and honestly, it just makes your game look unpolished.
The reality of Roblox is that the client—that's the player's computer—has a lot of control over their own character. Because of how the physics engine works, the client tells the server where they are, and the server usually just says, "Okay, cool, I believe you." This is great for smooth movement, but it's an open door for anyone with a basic execution tool. To stop this, you have to move away from trusting the player and start doing some math on the server side.
Why local scripts aren't enough
One of the biggest mistakes new developers make is trying to put their anti-cheat inside a LocalScript. It makes sense on paper: you check if the player's speed is too high and then kick them. But here's the catch—exploiters can see, disable, or even delete any LocalScript you put in the game. It's like putting a lock on a door but giving the burglar the key and a screwdriver.
To actually make a roblox anti cheat script fly speed jump system that works, you have to run your logic in a regular Script inside ServerScriptService. The server is the only environment the exploiter can't directly mess with. From up there, the server can watch every player's position and say, "Wait a minute, you just moved 100 studs in half a second, and that's literally impossible."
Catching the speed hackers
Speed hacking is the most common exploit because it's so simple to do. Most exploits just change the WalkSpeed property of the Humanoid. Since the server replicates movement, the exploiter moves faster on everyone's screen.
To catch this, you need to track the distance between a player's current position and their last known position. You can do this by running a loop on the server that checks every player every second or so. You calculate the distance using .Magnitude. If a player's WalkSpeed is 16, they shouldn't be moving more than about 18-20 studs per second (giving a little extra room for physics and lag).
If the distance is way higher than that, you know something is up. But don't just kick them immediately! Roblox physics can be weird. If a player gets hit by a car, blown up by a grenade, or flung by a glitchy part, they might move really fast for a split second. A good anti-cheat uses a "strike" system. You give them a few warnings or "rubber band" them back to their previous spot before you decide to kick them from the game.
Stopping the flyers
Flying is a bit more nuanced than just moving fast. Most fly exploits work by disabling the "FallingDown" state or using a BodyVelocity or BodyGyro object to keep the player in the air.
A clever way to handle a roblox anti cheat script fly speed jump check for flying is to look at the player's state and their distance from the ground. You can use Raycasting to check how far below the player the nearest solid floor is. If the player has been "falling" or "in air" for more than three or four seconds, but their height isn't decreasing, they are almost certainly flying.
You also have to keep an eye on the Y-axis (the vertical movement). If someone is jumping way higher than the JumpPower you set in your game, your script should flag that. If your game doesn't have jetpacks or elevators, and a player suddenly gains 50 studs of height in a second, they're definitely using a jump boost or a fly command.
Dealing with false positives and lag
This is the hardest part of writing any anti-cheat. Honestly, nothing feels worse for a player than getting kicked for "cheating" when they were actually just lagging. If a player's internet hangs for a second, their character might stand still on the server and then suddenly "teleport" forward when the connection catches up.
To prevent this, your roblox anti cheat script fly speed jump logic needs to be a bit "lazy." Instead of checking every single frame, check every 0.5 or 1.0 seconds. This gives the physics engine time to settle. Also, consider the environment. Are there launch pads in your game? Are there vehicles? If a player is sitting in a Seat object, you should probably disable the speed and fly checks for them, because vehicles often move way faster than humans.
Another trick is to check the player's ping. If their latency is spiking, you should loosen the restrictions. It's better to let a cheater get away with it for an extra ten seconds than it is to kick a loyal player who just has bad Wi-Fi.
Implementing a "Rubber Band" system
Instead of the "Kick" button being your first line of defense, try "Rubber Banding." This is when the server detects an illegal move and simply teleports the player back to where they were a second ago.
It's incredibly effective against speed hackers because it makes the game unplayable for them. They try to run forward, and they just keep snapping back. For a legitimate player who just had a lag spike, it's a minor annoyance rather than a game-ending kick. It also gives your script a chance to "double-check" if the player is actually cheating. If they get rubber-banded five times in a row within ten seconds, then you can be pretty confident it's time to bring out the ban hammer.
The importance of server-side authority
At the end of the day, a roblox anti cheat script fly speed jump fix is all about who has the final say. In a perfect world, the server would calculate every single movement, but that would make the game feel incredibly laggy for players. This "Client-Authoritative" movement is a compromise we live with.
Because of this, your anti-cheat should always be looking for "impossible" actions rather than "unlikely" ones. Don't set your speed limit to 16.01 if the max speed is 16. Set it to 25. Give that buffer for the engine's weirdness. The goal isn't to stop every single micro-advantage; it's to stop the blatant exploiters who are ruining the experience for everyone else.
Constant maintenance is key
Exploit creators are constantly finding new ways to bypass detection. They might find a way to spoof their velocity or use "TP-walking" which teleports them small distances very quickly to avoid speed checks.
You can't just write a roblox anti cheat script fly speed jump system once and forget about it. You need to check your logs, see if people are finding ways around it, and adjust your math. If you see a lot of people getting kicked at a specific part of your map, go check that spot—maybe there's a physics glitch that's triggering the anti-cheat.
Building a game is a lot of work, and protecting it is just as important. By focusing on server-side checks, being fair about lag, and using a strike system, you can keep your game fun and fair for everyone. It's a bit of a cat-and-mouse game, but keeping those exploiters at bay is totally worth the effort for the health of your community.