P.S : If among your concerns is source-code security, make a plugin / program that takes a lua source as input and produces the obfuscated version of it as the output. All of which is explained in the link above In short, think of it as a global dictionary ( _G.Dictionary ) except it has more features as compared to a global dictionary ( _G.Dictionary ). Modules can also be required via an asset id ( you can make this private or public as explained in here ) Personally I feel that modules also encourages more Functional Programming since you can also require this module from any script within the same environment ( server/client ), but this could also be just my own biased opinion because I’m almost religiously a Functional Programmer. With that aside, among the primary reason they added Modules was for developers to have a much more organized manner of scripting where you don’t need to repeat the same function more than once.

Scripts / LocalScripts & ModuleScripts are all obtainable by Exploiters if they have the ability to decompile your scripts ( This is currently thwarted due to the new lua vm but don’t rely on it to secure your code ), as long as it is stored in a place the client have access to.

UPDATE : This statement below is wrong, special thanks to for correcting my false belief here, the decompilation only applies to Localscripts and Modules.

Module script roblox