Anti-Exploit Basics Every Roblox Developer Should Know: Server Authority and Remote Validation
Posted: Wed Jul 15, 2026 4:55 pm
The short answer: anti-exploit on Roblox comes down to one rule. The server is the only thing you can trust, so every important decision has to be made and validated there. If your game logic trusts anything the client sends, an exploiter will eventually abuse it. Everything else in this post is just that rule applied in practice.
The same security mistakes show up in almost every new Roblox developer's game, so here is a proper rundown of anti-exploit basics: what exploiters can actually do, what server authority means, and how to validate your remotes so your economy does not get wrecked overnight.
[b]What an exploiter can actually do[/b]
First, understand your enemy. Roblox's own security documentation is blunt about this: a determined exploiter has complete control over their local state and network traffic. According to the official [url=https://create.roblox.com/docs/scripting/security/security-tactics]security and cheat mitigation tactics[/url] page, an exploiter can:
[list]
[*]Fire or invoke your RemoteEvents and RemoteFunctions at any frequency, with arbitrary arguments
[*]Modify their player's position, physics, and interactions with the world
[*]Read and decompile anything that replicates to the client, including scripts in ReplicatedStorage
[*]Take network ownership of unanchored parts and manipulate their physics
[*]Trigger proximity-based events from any distance
[/list]
Yes, Roblox ships the Hyperion (Byfron) anti-cheat in the client, and it catches plenty of injection tools, but never design your game assuming it catches everything. Client-side anti-cheat is a speed bump, not a wall. Your wall is the server.
[b]Server authority: the foundation[/b]
Server authority means the server is the single source of truth for game state. The client's job is to render the world, play effects, and send input. The server's job is to receive that input, decide whether it is legal, execute it, and replicate the result back.
A concrete example straight out of the official docs: a shop purchase. The client should only tell the server "I want to buy item X." The server then checks the real price from its own data, the player's real currency balance, and that the player is actually near the shop, and only then completes the transaction. If your client sends the price, or subtracts the coins locally and reports the new balance, you have already lost.
The same logic applies to combat. Never let the client report how much damage it dealt. The server should calculate damage from the weapon's stats, verify the attacker actually owns that weapon, and check that the target was in plausible range using server-side positions.
[b]Validating remotes properly[/b]
Every OnServerEvent handler is a door into your server, and exploiters will knock on all of them. Community threads like [url=https://devforum.roblox.com/t/best-way-to-protect-remoteevents-against-exploiters/1314739]this DevForum discussion on protecting RemoteEvents[/url] have been hammering the same points for years. Here is the checklist I use:
[list]
[*][b]Type check everything.[/b] If you expect a number, verify it is a number. Exploiters love sending tables, NaN, math.huge, or nil where you expect clean values. A NaN slipping into a damage calculation can corrupt stats or break logic.
[*][b]Sanity check the values.[/b] A number being a number is not enough. Is the damage within the weapon's actual range? Is the requested quantity positive and below the stack limit? Is the target position within a believable distance of the player?
[*][b]Use the built-in player identity.[/b] The first argument of OnServerEvent is the Player who fired the remote, verified by the engine. Never accept a player identity as a client-sent argument, or exploiters will act on behalf of other people.
[*][b]Verify ownership and state.[/b] Before honoring "use item X" or "claim reward Y," confirm on the server that the player owns X and has not already claimed Y. Tracking one-time actions server-side kills replay-style duplication tricks.
[*][b]Rate limit.[/b] The official docs tell you to threat model every feature by asking what happens if it is fired a thousand plus times per second. A simple per-player debounce or cooldown on each remote stops both reward farming and remote spam aimed at lagging your server.
[/list]
[b]Movement exploits and network ownership[/b]
Speed hacks, teleports, and fly scripts exist because Roblox gives clients network ownership of their own character. As the [url=https://create.roblox.com/docs/scripting/security/network-ownership]network ownership and physics exploits documentation[/url] explains, whoever owns an object's physics has complete authority over its simulation, and character properties can be modified locally without firing any events at all. That means a purely client-side speed check is trivially bypassed.
Practical mitigations:
[list]
[*]Run server-side movement validation. Compare distance travelled over time against what should be possible, with generous tolerance for latency. The docs themselves note that simple distance-over-time checks work fine for shooters but can false-flag in physics-heavy games, so tune the thresholds to your game and prefer teleporting the player back over instant bans.
[*]For gameplay-critical unanchored parts, use SetNetworkOwner to keep ownership on the server instead of letting the nearest client simulate them.
[*]Watch for extreme velocities. Exploiters set part velocities to absurd values, including Inf or NaN, to fling other players across the map. Clamp or reject these on the server.
[*]Do not trust Touched events for anything valuable, since exploiters can drag their character or owned parts through your triggers.
[/list]
[b]What never to trust from the client[/b]
Quick reference list. Treat all of these as suggestions, not facts:
[list]
[*]Any argument passed through a RemoteEvent or RemoteFunction
[*]Client-reported damage, hit confirmations, or kill credit
[*]Client-reported currency, inventory, or stat changes
[*]The client's own position for range checks on important actions
[*]Anything stored in ReplicatedStorage, which exploiters can read and decompile
[/list]
And one design habit that pays off forever: keep your sensitive logic and data in ServerScriptService and ServerStorage from day one. Retrofitting security into a game that trusted the client is far more painful than building it right the first time.
[b]Frequently asked questions[/b]
[b]Q: Can I just give my remotes random or hidden names so exploiters cannot find them?[/b]
A: No. Exploiters can enumerate every remote in your game and log all traffic through them regardless of naming. Obscurity buys you nothing; validation is the only real defense.
[b]Q: Is client-side anti-cheat completely useless then?[/b]
A: Not useless, just not trustworthy. It can deter casual cheaters and catch low-effort scripts, but since exploiters control the client, they can disable or spoof it. Use it as an extra layer, never as your foundation.
[b]Q: Do I need to secure RemoteFunctions differently from RemoteEvents?[/b]
A: The validation rules are identical, but RemoteFunctions add a risk: if the server invokes the client and an exploiter never responds, or responds with garbage, your server code can hang or misbehave. Avoid server-to-client invokes entirely where possible.
[b]Q: My game is small, do exploiters even care?[/b]
A: Yes. Free executor scripts get run in random games constantly, and small games with visible currency or trading are easy targets. Building on server authority from the start costs you very little; cleaning up a duped economy costs a lot.
That is the foundation. If you have been hit by a specific exploit, or you are unsure whether one of your remotes is safe, post the details below and I or someone else here will take a look. I am also curious what validation patterns the scripters among you have settled on, so share your setups.
The same security mistakes show up in almost every new Roblox developer's game, so here is a proper rundown of anti-exploit basics: what exploiters can actually do, what server authority means, and how to validate your remotes so your economy does not get wrecked overnight.
[b]What an exploiter can actually do[/b]
First, understand your enemy. Roblox's own security documentation is blunt about this: a determined exploiter has complete control over their local state and network traffic. According to the official [url=https://create.roblox.com/docs/scripting/security/security-tactics]security and cheat mitigation tactics[/url] page, an exploiter can:
[list]
[*]Fire or invoke your RemoteEvents and RemoteFunctions at any frequency, with arbitrary arguments
[*]Modify their player's position, physics, and interactions with the world
[*]Read and decompile anything that replicates to the client, including scripts in ReplicatedStorage
[*]Take network ownership of unanchored parts and manipulate their physics
[*]Trigger proximity-based events from any distance
[/list]
Yes, Roblox ships the Hyperion (Byfron) anti-cheat in the client, and it catches plenty of injection tools, but never design your game assuming it catches everything. Client-side anti-cheat is a speed bump, not a wall. Your wall is the server.
[b]Server authority: the foundation[/b]
Server authority means the server is the single source of truth for game state. The client's job is to render the world, play effects, and send input. The server's job is to receive that input, decide whether it is legal, execute it, and replicate the result back.
A concrete example straight out of the official docs: a shop purchase. The client should only tell the server "I want to buy item X." The server then checks the real price from its own data, the player's real currency balance, and that the player is actually near the shop, and only then completes the transaction. If your client sends the price, or subtracts the coins locally and reports the new balance, you have already lost.
The same logic applies to combat. Never let the client report how much damage it dealt. The server should calculate damage from the weapon's stats, verify the attacker actually owns that weapon, and check that the target was in plausible range using server-side positions.
[b]Validating remotes properly[/b]
Every OnServerEvent handler is a door into your server, and exploiters will knock on all of them. Community threads like [url=https://devforum.roblox.com/t/best-way-to-protect-remoteevents-against-exploiters/1314739]this DevForum discussion on protecting RemoteEvents[/url] have been hammering the same points for years. Here is the checklist I use:
[list]
[*][b]Type check everything.[/b] If you expect a number, verify it is a number. Exploiters love sending tables, NaN, math.huge, or nil where you expect clean values. A NaN slipping into a damage calculation can corrupt stats or break logic.
[*][b]Sanity check the values.[/b] A number being a number is not enough. Is the damage within the weapon's actual range? Is the requested quantity positive and below the stack limit? Is the target position within a believable distance of the player?
[*][b]Use the built-in player identity.[/b] The first argument of OnServerEvent is the Player who fired the remote, verified by the engine. Never accept a player identity as a client-sent argument, or exploiters will act on behalf of other people.
[*][b]Verify ownership and state.[/b] Before honoring "use item X" or "claim reward Y," confirm on the server that the player owns X and has not already claimed Y. Tracking one-time actions server-side kills replay-style duplication tricks.
[*][b]Rate limit.[/b] The official docs tell you to threat model every feature by asking what happens if it is fired a thousand plus times per second. A simple per-player debounce or cooldown on each remote stops both reward farming and remote spam aimed at lagging your server.
[/list]
[b]Movement exploits and network ownership[/b]
Speed hacks, teleports, and fly scripts exist because Roblox gives clients network ownership of their own character. As the [url=https://create.roblox.com/docs/scripting/security/network-ownership]network ownership and physics exploits documentation[/url] explains, whoever owns an object's physics has complete authority over its simulation, and character properties can be modified locally without firing any events at all. That means a purely client-side speed check is trivially bypassed.
Practical mitigations:
[list]
[*]Run server-side movement validation. Compare distance travelled over time against what should be possible, with generous tolerance for latency. The docs themselves note that simple distance-over-time checks work fine for shooters but can false-flag in physics-heavy games, so tune the thresholds to your game and prefer teleporting the player back over instant bans.
[*]For gameplay-critical unanchored parts, use SetNetworkOwner to keep ownership on the server instead of letting the nearest client simulate them.
[*]Watch for extreme velocities. Exploiters set part velocities to absurd values, including Inf or NaN, to fling other players across the map. Clamp or reject these on the server.
[*]Do not trust Touched events for anything valuable, since exploiters can drag their character or owned parts through your triggers.
[/list]
[b]What never to trust from the client[/b]
Quick reference list. Treat all of these as suggestions, not facts:
[list]
[*]Any argument passed through a RemoteEvent or RemoteFunction
[*]Client-reported damage, hit confirmations, or kill credit
[*]Client-reported currency, inventory, or stat changes
[*]The client's own position for range checks on important actions
[*]Anything stored in ReplicatedStorage, which exploiters can read and decompile
[/list]
And one design habit that pays off forever: keep your sensitive logic and data in ServerScriptService and ServerStorage from day one. Retrofitting security into a game that trusted the client is far more painful than building it right the first time.
[b]Frequently asked questions[/b]
[b]Q: Can I just give my remotes random or hidden names so exploiters cannot find them?[/b]
A: No. Exploiters can enumerate every remote in your game and log all traffic through them regardless of naming. Obscurity buys you nothing; validation is the only real defense.
[b]Q: Is client-side anti-cheat completely useless then?[/b]
A: Not useless, just not trustworthy. It can deter casual cheaters and catch low-effort scripts, but since exploiters control the client, they can disable or spoof it. Use it as an extra layer, never as your foundation.
[b]Q: Do I need to secure RemoteFunctions differently from RemoteEvents?[/b]
A: The validation rules are identical, but RemoteFunctions add a risk: if the server invokes the client and an exploiter never responds, or responds with garbage, your server code can hang or misbehave. Avoid server-to-client invokes entirely where possible.
[b]Q: My game is small, do exploiters even care?[/b]
A: Yes. Free executor scripts get run in random games constantly, and small games with visible currency or trading are easy targets. Building on server authority from the start costs you very little; cleaning up a duped economy costs a lot.
That is the foundation. If you have been hit by a specific exploit, or you are unsure whether one of your remotes is safe, post the details below and I or someone else here will take a look. I am also curious what validation patterns the scripters among you have settled on, so share your setups.