How vast the world within a work feels to the audience.
"Scope", in a literary context, refers to how vast the world within a work "feels". It's the difference between a universe that might as well stop once you reach the county line and one that seems to go one forever, stretching across deep space and time. Whether a story has a large or small scope has no bearing on how good it is, but in general, media with a large scope are considered more ambitious or difficult. Stories with large scope also tend more to be world-driven and plot-based, while works with smaller scope tend to be more character-based and introspective. There is no precise way to really calculate scope, it's more of a gut feeling than anything else, but there are certain story elements an author might use in an attempt to give a story more scope. Things which contribute to the scope of a work include the distance across geography within which the plot takes place in, the length of time which it takes place in, and the implied impact of the climax across distance and time. Very often the scope of a work is closely related to how threatening the antagonist is. A Cryptic Background Reference, mentioning places or cultures that may have little bearing on the immediate plot, often serve to give a sense that there is a world out there beyond the bounds of the story. This and other forms of Narrative Filigree can give both scope and realism. A Fantasy World Map can also serve to increase scope and give readers a sense of scale. Being a sliding scale, the discrete levels below aren't all-inclusive.
Level 0: The Room
Level 1: A Single BuildingFor when one room is too limited, but you don't want to strain the budget by forcing your set designers to come up with different settings. Bonus points if it's an office building or hospital and you can re-use rooms.
Level 2: The Same Three PlacesThe typical sitcom has three or four regular sets, with other temporary sets built as needed.
Level 3: The CityThe needs of the story require multiple locations beyond just a few hangouts, but don't extend the need beyond the city limits.
Level 4: Following the RangersThe story moves from place to place, without feeling the need to define precisely where they are or how far they've gone. There's a lack of boundaries, a feeling of freedom. See also Walking the Earth
Level 5: This Country of OursFor when the work takes place in a defined local, but with an expanse and a variety.
Level 6: A Continent of NationsWorks that take place within an international context. The action can occur across multiple nations or within one nation informed by the presence of others. The point is that there is a larger world, of which the action is one part.
Level 7: A Whole WorldFor those works that seek to be epic in scope, building an entire world.
Level 8: The Universe!For when one world just isn't enough. Galaxies also count.
Level Infinite: EVERYTHING IS MINEFuck it. Everywhere is my setting, everyone is my character, and you bitches can go cry about it if you don't like it.