Getting your first roblox anti speed hack script up and running is basically a rite of passage for any developer who wants their game to actually be playable. Let's be real for a second: there is nothing that kills the vibe of a well-made game faster than some random person zooming across the map at three hundred miles per hour while everyone else is trying to play fair. It makes your leaderboards meaningless, ruins competitive balance, and honestly, it just looks bad. If you're building something you want people to take seriously, you can't just rely on Roblox's built-in physics to keep things in check. You need a custom solution that lives on the server and keeps a watchful eye on how fast everyone is moving.
Why the server has to be the boss
The biggest mistake I see new developers make is trying to handle anti-exploits on the client side. If you put your roblox anti speed hack script inside a LocalScript, you've already lost the battle. Think about it: the exploiter already has control over their own computer. If your "security" is running on their machine, they can just delete the script, disable it, or even modify it to tell the server that everything is totally fine while they're actually teleporting around.
To make an anti-cheat that actually works, the logic has to happen on the server. The server is the "source of truth." It doesn't matter what the player's computer says; it only matters what the server sees. In a server-side script, you're essentially saying, "I know you told me you're over there, but based on where you were half a second ago, there's no way you could have traveled that far." When the server becomes the referee, life gets a lot harder for the people trying to break your game.
The basic logic of checking speed
At its heart, a roblox anti speed hack script is really just a math problem involving distance and time. We all remember the formula from school: speed equals distance divided by time. In Roblox, we can check this by tracking a player's position at regular intervals.
Most effective scripts use a loop—usually connected to something like RunService.Heartbeat or just a simple task.wait()—to grab the player's current position and compare it to where they were the last time we checked. By using the .Magnitude property of a Vector3, you can find the exact distance between those two points. If that distance is way higher than what their WalkSpeed should allow, you've caught yourself a speeder.
However, you can't just set the limit to exactly 16 (the default WalkSpeed). You have to leave a little "buffer" or "threshold." If you're too strict, you'll end up punishing players who are just experiencing a tiny bit of lag or who got a slight physics boost from bumping into a wall. I usually like to set the limit about 5 to 10 studs higher than the maximum possible speed just to be safe.
Handling the magnitude check
When you're calculating that distance, you have to be a bit careful about the Y-axis. In Roblox, players fall. Gravity can make a player move downwards way faster than they can ever walk forward. If your roblox anti speed hack script doesn't account for falling, you're going to end up kicking people every time they jump off a high ledge.
A clever trick is to only calculate the distance on the X and Z axes. By ignoring the Y-axis (height), you're only checking how fast they are moving across the ground. This prevents "false positives" from falling while still catching people who are zooming horizontally across the map.
The strike system vs. instant bans
One of the most annoying things as a player is getting kicked from a game because your internet lagged for a second. We've all been there—the screen freezes, then everything speeds up for a moment to catch up. To a dumb script, that looks like a speed hack. That's why you shouldn't just kick someone the very first time they exceed the speed limit.
Instead, a good roblox anti speed hack script uses a "strike" or "violation" system. Give the player a hidden score. Every time they go too fast, add a point. If they move normally for a while, take a point away. Only when they hit five or ten strikes do you actually take action. This way, a lag spike might give them one strike that immediately disappears, but an actual exploiter will rack up those points in seconds.
Dealing with legitimate speed boosts
Things get a little more complicated when your game actually wants players to go fast. Maybe you have power-ups, sprint mechanics, or vehicles. If your roblox anti speed hack script is hard-coded to a speed of 16, it's going to break your own game features.
The way around this is to make your script dynamic. Instead of checking against a hard number, have the script check against the player's current Character.Humanoid.WalkSpeed. But wait—there's a catch! If an exploiter changes their WalkSpeed on their own screen, the server doesn't always see that change right away.
The best practice is to have a "MaxAllowedSpeed" variable stored on the server for each player. Whenever your game gives a player a speed boost, the server should update that variable. Then, the anti-cheat script checks the player's movement against that server-side variable. It's a bit more work to set up, but it's the only way to make sure your legitimate players don't get flagged while using the cool items you built for them.
What to do when you catch someone
So, your script has confirmed that someone is definitely cheating. Now what? You have a few options, and "instantly ban them forever" isn't always the best one.
- The Rubber Band: This is my favorite. Instead of kicking the player, the server just teleports them back to their "last known good position." It's incredibly frustrating for the exploiter because they try to run fast and just keep snapping back to where they started. It keeps them in the game but makes their cheats useless.
- The Kick: This is the standard. It gets them out of the server so they stop bothering people. It's effective, but they can just join another server.
- The Log: If you're not 100% sure about your script yet, just have it send a message to a Discord webhook or an admin panel. This lets you watch the "suspicious" players and see if your script is actually working or if it's just flagging innocent people.
Keeping performance in mind
You might be thinking, "If I'm checking every player's position every single frame, won't that lag my server?" It's a valid concern. If you have a 50-player server and you're doing complex math 60 times a second for every single one of them, you're going to feel it.
To keep your roblox anti speed hack script efficient, you don't need to check every single frame. Checking once every 0.5 or 1.0 seconds is usually plenty. Exploits happen over time, and catching someone a half-second after they start zooming isn't going to break the game. You can also stagger the checks so the server isn't processing everyone at the exact same millisecond.
Final thoughts on game security
At the end of the day, no roblox anti speed hack script is 100% perfect. It's a bit of an arms race between developers and exploiters. You'll probably find yourself tweaking your thresholds and adjusting your logic as you see how people play your game.
The goal isn't necessarily to make an impenetrable fortress—that's almost impossible. The goal is to make it so difficult and annoying to cheat in your game that the exploiters just give up and go find an easier target. By implementing a solid, server-side check with a fair strike system, you're already ahead of 90% of the games on the platform. Keep it simple, keep it on the server, and always leave a little room for a laggy player to breathe. Your community will definitely thank you for it when they can actually enjoy a fair game.