By scope is meant the ability of one region of code to see variables in another region of code. The rules of scope for AppleScript are remarkably involvedas involved of those of any computer language I know. They are a perennial source of pitfalls for beginning and experienced programmers alike. If you don't understand the rules of scope, or (even worse) if you try to ignore them, you'll find your scripts mysteriously going wrong in confusing ways. This chapter discusses the rules of scope, along with a powerful advanced scope-related feature of AppleScriptclosures.