This comprehensive guide breaks down the mechanics of network replication, explains how fake lag scripts function in Roblox Luau, provides a safe development example, and discusses how game developers can detect and prevent this behavior.

As a developer, relying entirely on Roblox’s default physics replication leaves your game vulnerable to fake lag abuse. You must implement server-side validation. 1. Server-Side Magnitude Checks

is a core security feature in Roblox designed to prevent a client (player) from making unauthorized changes to the server. When a script is "FE compatible," it means it works within these security constraints, typically by exploiting aspects of the game that still sync from client to server, such as character position and animations. How Fake Lag Works