Roblox RemoteEvent Security: How to Validate, Rate Limit, and Protect Your Game
Posted: Sun Oct 18, 2026 10:21 am
Roblox RemoteEvent Security: How to Validate, Rate Limit, and Protect Your Game
Any time a client can trigger an action on the server, there is potential for abuse. RemoteEvents and RemoteFunctions are the most common attack vector. This guide covers the validation layers every Roblox developer should apply.
Never Trust the Client
A determined exploiter has complete control over their local state and network traffic. They can decompile any replicated LocalScript, fire RemoteEvents at any frequency with arbitrary arguments, and modify anything in their local DataModel.
All critical logic must be validated server-side or run exclusively on the server. Assume every piece of data sent from the client has been manipulated.
Validate Every Remote Input
Every argument sent from a client must be validated by the server before it is used. Apply these layers based on what the remote does.
Context and permission validation is necessary for remotes that affect game state, progression, or other players. The server must verify the player has the necessary permissions. Is the player close enough to a shop to buy something? Do they have a key required to open a door? Is their character alive?
Type and structure validation prevents exploiters from sending technically valid types that are extremely large, long, or malformed. An exploiter could send an incredibly large string to bog down the server, or send a table in place of an Instance. Check the class and expected location of any Instance arguments.
Value validation ensures values are within expected boundaries. A purchase quantity should be greater than zero. An item ID should correspond to a real item in your game. Both [c]inf[/c] and [c]NaN[/c] are valid number types but can cause major issues if not handled. Use [c]math.isfinite()[/c] to detect and reject them.
The Danger of NaN[/c]
An exploiter can send NaN (Not a Number) as an argument. NaN fails all standard comparisons, allowing it to subtly bypass logical checks. In a trading system, a fraudulent offer with NaN gold passes type checks, range checks, and inventory checks because every comparison returns false. Use [c]math.isfinite()[c] before any numeric operation on client data.
Rate Limiting
Whenever server-side logic can be triggered by a client, there is a possibility of spam. Rate limiting controls how frequently these actions can be performed.
Roblox API calls like DataStoreService and BadgeService have built-in rate limits. Computationally expensive operations consume significant server resources. Exploitable mechanics like granting invulnerability or awarding currency can be abused if performed rapidly.
Implement a server-side cooldown using a table and [c]tick()[/c]:
Never rely solely on a client-side rate limit. Exploiters can bypass anything enforced on their local machine.
DataStore Security
Exploiters may take advantage of invalid data, race conditions to corrupt saves, or duplicate items in a DataStore. Sanitize all data before saving:
A honeypot is a RemoteEvent that appears legitimate but is never used by any legitimate client script. Any traffic it receives must be from an exploiter. When the server detects this remote being fired, log the incident and kick the player.
You can also design RemoteEvents with specific directional purposes: some exclusively for client to server communication, others exclusively for server to client. The server tracks which direction each remote should be used. If an exploiter fires a server-to-client remote from the client, that is a reliable detection signal.
FAQ
What is the most important security rule?
Never trust the client. Validate everything server-side before using it.
How do I prevent remote spam?
Implement a server-side cooldown using a table and [c]tick()[/c]. Never rely on client-side rate limits.
Why is NaN dangerous?
NaN fails all standard comparisons, so it can bypass range checks, inventory checks, and other logical validation. Use [c]math.isfinite()[/c] to reject it.
Sources
Any time a client can trigger an action on the server, there is potential for abuse. RemoteEvents and RemoteFunctions are the most common attack vector. This guide covers the validation layers every Roblox developer should apply.
Never Trust the Client
A determined exploiter has complete control over their local state and network traffic. They can decompile any replicated LocalScript, fire RemoteEvents at any frequency with arbitrary arguments, and modify anything in their local DataModel.
All critical logic must be validated server-side or run exclusively on the server. Assume every piece of data sent from the client has been manipulated.
Validate Every Remote Input
Every argument sent from a client must be validated by the server before it is used. Apply these layers based on what the remote does.
Context and permission validation is necessary for remotes that affect game state, progression, or other players. The server must verify the player has the necessary permissions. Is the player close enough to a shop to buy something? Do they have a key required to open a door? Is their character alive?
Type and structure validation prevents exploiters from sending technically valid types that are extremely large, long, or malformed. An exploiter could send an incredibly large string to bog down the server, or send a table in place of an Instance. Check the class and expected location of any Instance arguments.
Value validation ensures values are within expected boundaries. A purchase quantity should be greater than zero. An item ID should correspond to a real item in your game. Both [c]inf[/c] and [c]NaN[/c] are valid number types but can cause major issues if not handled. Use [c]math.isfinite()[/c] to detect and reject them.
The Danger of NaN[/c]
An exploiter can send NaN (Not a Number) as an argument. NaN fails all standard comparisons, allowing it to subtly bypass logical checks. In a trading system, a fraudulent offer with NaN gold passes type checks, range checks, and inventory checks because every comparison returns false. Use [c]math.isfinite()[c] before any numeric operation on client data.
Rate Limiting
Whenever server-side logic can be triggered by a client, there is a possibility of spam. Rate limiting controls how frequently these actions can be performed.
Roblox API calls like DataStoreService and BadgeService have built-in rate limits. Computationally expensive operations consume significant server resources. Exploitable mechanics like granting invulnerability or awarding currency can be abused if performed rapidly.
Implement a server-side cooldown using a table and [c]tick()[/c]:
Code: Select all
lua
local RemoteCooldown = {}
PlayerService.PlayerAdded:Connect(function(player)
RemoteCooldown[player.UserId] = tick()
end)
SomeRemote.OnServerEvent:Connect(function(player)
if tick() - RemoteCooldown[player.UserId] >= 0.2 then
RemoteCooldown[player.UserId] = tick()
-- process the request
end
end)
DataStore Security
Exploiters may take advantage of invalid data, race conditions to corrupt saves, or duplicate items in a DataStore. Sanitize all data before saving:
- Instance values cannot be serialized into a DataStore. Use type validation to prevent them.
- Strings of arbitrary length should be checked and capped. DataStores have data limits.
- Table indices cannot be NaN or nil. Iterate over all tables passed by the client and verify indices are valid.
- DataStores only accept valid UTF-8 characters. Use [c]utf8.len()[/c] to sanitize strings.
- Validate all data before trade operations. Use transaction-like patterns where all players' data is validated before committing changes.
- Implement proper error handling that reverts all changes if any part fails.
A honeypot is a RemoteEvent that appears legitimate but is never used by any legitimate client script. Any traffic it receives must be from an exploiter. When the server detects this remote being fired, log the incident and kick the player.
You can also design RemoteEvents with specific directional purposes: some exclusively for client to server communication, others exclusively for server to client. The server tracks which direction each remote should be used. If an exploiter fires a server-to-client remote from the client, that is a reliable detection signal.
FAQ
What is the most important security rule?
Never trust the client. Validate everything server-side before using it.
How do I prevent remote spam?
Implement a server-side cooldown using a table and [c]tick()[/c]. Never rely on client-side rate limits.
Why is NaN dangerous?
NaN fails all standard comparisons, so it can bypass range checks, inventory checks, and other logical validation. Use [c]math.isfinite()[/c] to reject it.
Sources