: External execution environments use a custom function, often saveinstance() , to decompile a live game into a .rbxl file. This is generally used for "stealing" maps or studying how a game is built.
If a player’s client requests assets from IDs not normally available in your game, flag them for session termination. Roblox SaveInstance Script
If you want to learn from others, play their games, study their public resources, and respect their IP. If you want to protect your own creations, stay updated on Roblox’s security patches and adopt anti-save strategies. : External execution environments use a custom function,
File → or Save to File (.rbxlx) .