Using a Roblox ISLClosure Script for Your Projects

If you've been hanging around the technical side of the community lately, you've probably seen the roblox islclosure script mentioned in forums or Discord servers dedicated to advanced Luau development. It's one of those terms that sounds like absolute gibberish if you're just starting out, but once you get the hang of how Roblox handles functions, it actually makes a ton of sense. Essentially, it's a way to figure out what kind of function you're looking at—specifically, whether it was written in Lua or if it's a built-in "C" function. ...

February 13, 2026 · 6 min · Loreen Toriello