What Are The Different Types Of Scripts In Roblox: Guide

LocalScripts run on each player’s device while ServerScripts run on the game server.

I’ve built and shipped multiple Roblox games, and I’ll walk you through LocalScript vs ServerScript with clear examples, practical tips, and common pitfalls. This guide explains the different types of scripts in Roblox, when to use each, how they talk to each other, and how to keep your game fast and secure.

What are the types of scripts in Roblox?

Roblox has three primary script types you’ll meet: Script, LocalScript, and ModuleScript. Script is the classic server-side script that runs on the server and controls global game state. LocalScript runs on a client (player) and controls UI, input, and camera behavior. ModuleScript is a reusable container for functions and data that can be required by both server and client scripts when used correctly.

• Script (ServerScript)
  • Runs on the server only.
  • Controls game rules, physics, and shared state.
• LocalScript
  • Runs on a player’s device only.
  • Handles UI, input, and local effects.
• ModuleScript
  • Stores shared code and utilities.
  • Can be required by Scripts or LocalScripts depending on where it’s placed.

Understanding these types of scripts in Roblox lets you design secure and efficient game logic from the start. Use each type for the job it was made for to avoid bugs and exploits.

Key differences: LocalScript vs ServerScript

LocalScript vs ServerScript differ in environment, authority, and purpose. The server is authoritative and shared across all players; the client is local and private to each player. This affects what each script can access and how changes replicate.

• Execution environment
  • ServerScript runs on Roblox servers and can access server-only services.
  • LocalScript runs in the player’s client and can access player UI and input.
• Permissions and API access
  • Server can read/write DataStore, manage Instances globally, and spawn NPCs.
  • Client can manipulate Camera, Gui, and UserInputService.
• Replication and trust
  • Server changes replicate to all clients and are authoritative.
  • Client changes are local and must not be trusted for critical rules.
• Placement matters
  • LocalScript runs when placed in StarterPlayerScripts, StarterGui, StarterCharacterScripts, or a player’s Backpack.
  • Script runs in ServerScriptService, Workspace, or other server-side containers.

These core differences shape how you design gameplay and security in your game.

How LocalScript and ServerScript communicate

LocalScript vs ServerScript must talk to each other safely. They do so using RemoteEvents and RemoteFunctions. RemoteEvents are best for one-way or broadcast messages. RemoteFunctions let a client request data and wait for a server response.

• RemoteEvent pattern
  • Client fires an event to the server to request an action.
  • Server validates the request and fires events back to clients as needed.
• RemoteFunction pattern
  • Client calls a RemoteFunction for a direct answer from the server.
  • Use sparingly to avoid blocking or lag.
• Validation steps
  • Server always validate inputs: positions, amounts, IDs, and permissions.
  • Never rely solely on data sent from the client.

From experience, using RemoteEvents for most interactions keeps latency low and server logic clean. Always assume the client may lie and validate on receipt.

When to use LocalScript vs ServerScript — practical scenarios

Use the right script type for the right task. This keeps code secure, fast, and easy to maintain.

• Use LocalScript for:
  • UI updates, HUD, menus, and local animations.
  • Camera control, local sound effects, and input handling.
  • Cosmetic effects that don’t change game rules.
• Use ServerScript for:
  • Game rules, leaderboards, and DataStore saves.
  • Spawning enemies, awarding currency, and matchmaking.
  • Anything that affects multiple players or persistent state.
• Use ModuleScript for:
  • Shared utility functions, constants, and math helpers.
  • Keep logic consistent by requiring the same module from server and client where safe.

I once caused a bug by moving a UI update to a ServerScript; the code never ran for the client. That taught me to place LocalScript code where the client can execute it.

Common mistakes and debugging tips

Beginners often mix up LocalScript vs ServerScript responsibilities. Here are common traps and how to fix them.

• LocalScript not running
  • Check placement: LocalScripts don’t run in ServerScriptService or plain Server storage.
  • Ensure the LocalScript runs in a valid container like StarterGui or StarterPlayerScripts.
• Trusting the client
  • Never accept client-sent currency values or kill confirmations without validation.
  • Recompute important values on the server.
• Rate and memory issues
  • Avoid firing RemoteEvents in tight loops; batch or debounce requests.
  • Keep long-running server loops efficient and use task.wait responsibly.
• Debugging tips
  • Use print statements on both server and client.
  • Test with multiple players in Studio to check replication and race conditions.

My tip: log both sides of RemoteEvent flows. It saved hours of guesswork when tracking down a desync bug.

Performance and security considerations

Balancing performance and safety is key when mixing LocalScript vs ServerScript. The server should remain the source of truth, while the client handles presentation.

• Minimize network traffic
  • Send only essential data via RemoteEvents.
  • Use compression or packed tables for frequent updates.
• Prevent exploits
  • Validate all client requests on the server.
  • Use server-side checks for purchases, inventory changes, and score updates.
• Scale responsibly
  • Spread heavy computations across time or offload to lightweight threads.
  • Use pruning and cleanup for temporary Instances to avoid memory leaks.

Design with security and performance in mind from day one. It reduces later rework and improves player experience.

Example patterns and starter snippets

Here are short patterns you can adapt for LocalScript vs ServerScript communication and structure.

• Fire from client to server (RemoteEvent)
  • Client LocalScript fires a RemoteEvent with an action request.
  • ServerScript listens, validates, and executes secure actions.
• Request/response (RemoteFunction)
  • LocalScript calls RemoteFunction to request a player-specific value.
  • ServerScript computes and returns the result.

Sample pseudo-flow

• Client (LocalScript)
  • Player clicks a button -> fire RemoteEvent "RequestBuy" with itemId.
• Server (ServerScript)
  • On RemoteEvent, validate player coins and itemId.
  • Deduct coins and give item, then fire client event for success.

These templates cover common use cases and keep LocalScript vs ServerScript roles clear.

Frequently Asked Questions of What are the different types of scripts in Roblox (LocalScript vs ServerScript)?

What is the main difference between a LocalScript and a ServerScript?

LocalScript runs only on the player’s device and handles UI and input. ServerScript runs on the game server and manages global game state and authoritative decisions.

Where should I place a LocalScript so it runs correctly?

Place LocalScripts in StarterGui, StarterPlayerScripts, StarterCharacterScripts, or a player’s Backpack for them to run. They will not run if placed in ServerScriptService or server-only containers.

Can ModuleScripts be used by both LocalScript and ServerScript?

Yes, ModuleScripts can be required by both sides if the ModuleScript is placed in a location accessible to both. Keep server-only logic out of modules used by clients to avoid security issues.

How do I safely let players buy items from the client?

Send a RemoteEvent from the client to the server with the purchase request, then validate funds and item availability on the server. Only the server should modify player currency and inventory.

Why is the server considered authoritative?

The server maintains the shared game state that replicates to all players and prevents clients from making trusted changes. This authority reduces cheating and keeps gameplay consistent.

Conclusion

Understanding the types of scripts in Roblox, especially LocalScript vs ServerScript, is essential for making secure, smooth, and engaging games. Use LocalScripts for client-only tasks like UI and input, ServerScripts for authoritative logic and persistence, and ModuleScripts for shared helpers. Start small, validate data on the server, and use RemoteEvents/RemoteFunctions thoughtfully.

Build one clear rule into your workflow: trust the server, use the client for presentation, and keep communication simple. Try applying one pattern from this guide in your next project, leave a comment about what worked, or subscribe to follow more practical Roblox tips.