Would this delete for everyone?

If I said, in a local script, “game.StarterGui.(thing):Destroy()” would that delete it for everyone, or just the one person, since it’s a local script?

It would delete for just that one person, sense it is on the client.

Deleting items in the StarterGui makes it so that players no longer start off with that GUI. If you are deleting a GUI in a player’s PlayerGui then it only deletes it for them.