Roblox Remote Event

RemoteEvents Are the Most Misunderstood Part of the Roblox Networking Stack

Most people treat them like magic buttons that do whatever you tell them to do. They don't. A Roblox Remote Event is literally just a pipe between the client and the server with no handshake, no guaranteed delivery confirmation, and no way to make the server respond back through the same event. That distinction matters more than you might think.

Here is the basic flow. You create the event on the server side, put it in ReplicatedStorage or somewhere accessible, and connect a .OnServerEvent handler. The client fires it with .FireClient or .FireServer and passes along whatever arguments you need. That is the entire contract. Everything else is implementation detail and usually the source of bugs. The arguments get serialized through RBXSPC, which means they have to be plain Lua types. Numbers, strings, booleans, vectors, CFrame, instances, tables containing only those types. Try passing a function reference or a thread and the whole thing errors out silently on the client side. The server never sees the fire. I spent about three days chasing a ghost bug where my entire economy system stopped working and it turned out I was accidentally trying to pass a custom module table through the event. There is also a bandwidth ceiling even though Roblox never really documents it. Roughly 50 kilobytes per event is where things start feeling sluggish on lower tier connections. That is per event, per player, per frame. So if you are firing inventory updates for twenty players simultaneously you are already in dangerous territory.

The most common mistake I see is people using remote events for something that requires synchronization or acknowledgment. They fire a request and immediately update local state as if the server already processed it. It hasn't. The server processes events in the same priority order as everything else on the thread. Under heavy load your event might queue behind twenty other jobs and sit there for half a second or more. Use RemoteFunctions when you need a response. Use them for validation checks, data queries, or anything where the client cannot proceed without server confirmation. The overhead is slightly higher because of the request-response cycle but you avoid entire categories of race condition bugs. I ran into a specific edge case recently that still trips me up when I come back to old projects. When you use a remote event inside a loop to handle particle effects for a projectile system, the event fires correctly but the argument serialization for Vector3 values can drift slightly due to floating point conversion. Not enough to matter in normal gameplay, but in a precise hit detection system using custom raycasting the positions would desync between what the server recorded and what the client rendered. My workaround was to run the hit detection entirely on the server and only send a boolean confirmation to the client instead of the coordinate data.

Another thing nobody talks about is the cleanup problem. If you disconnect an OnServerEvent handler inside a character removal script but forget to also nil out the connection variable, the closure stays alive and holds references to the Character object and any variables in scope. In a server handling thousands of character respawns per hour this becomes a genuine memory leak. I tracked one down to roughly 40 megabytes of accumulated garbage over six hours before I realized what was happening. The workaround is straightforward but easy to forget. Store every connection in a dictionary keyed by player or object reference, then iterate and disconnect them during cleanup. Do not rely on the Garbage Collector to clean up disconnected handlers. It does not do that consistently enough for production servers. Rate limiting is another area where people make life harder than it needs to be. Put a simple cooldown check at the top of your OnServerEvent handler. Reject fires that come in faster than your design allows. The server should never trust the client to self-regulate. I built a tool system once where I assumed clients were firing at a reasonable rate and learned the hard way that a scripted exploit can fire a remote event thousands of times per second. The server crashed from event handler overload within minutes.

RemoteEvents also do not support event priorities in any meaningful way. All events for a given instance process sequentially on the same thread. If your handler does anything computationally expensive like iterating through a large table or calling multiple remote events itself you are blocking everything behind it. Keep handlers thin. Spawn long-running logic into coroutines if you must. The rule of thumb is that an event handler should complete in under five milliseconds under normal conditions. If you need to send large amounts of structured data regularly, consider switching to a module-based approach where the server holds authoritative state and the client only receives deltas or updates on demand. RemoteEvents were never designed to replace a proper networking layer. They are fast, they are simple, and they break your project in exactly the ways you least expect when you try to make them do more than they were built for.