As Hobo says, a session is analogous to a chapter. Another popular one these days is to think of sessions as episodes, and overarching plots as season arcs. In a game based on superhero comics it might be appropriate to think of sessions as issues. I don't do this btw but I don't regard it as a crazy view, or as 'not a rpg'.
Chapters, scenes, and episodes are characterized by rising and falling action, plot progression, and so on. They're discrete parts of a story, deliberately chosen by the author and editor.
Compare that to, "Okay, it's eleven o'clock, let's stop here and pick up here again next week." That's not a chapter or an episode, unless you believe a writer simply inserts a new chapter heading every thirty pages regardless of what's going on in the story.
The climax of Tomb of Horrors, a very linear adventure, is when the demi-lich skull rises up and starts sucking souls. That's a scene, and a dramatic one too.
Tournament module, and one specifically not recommended for on-going campaigns, if I remember correctly.
And I've neither played it nor run it, by the way.
GDQ is a story arc. It's a story arc as it is written, the story is clear in the text, before the PCs ever interact with it.
So anytime locations are linked by a common purpose, that's automatically a story arc? I don't think so.
In the Temple of Elemental Evil, collecting the gems to place in the Orb of Golden Death is a plot. As are similar 'collect the set' MacGuffins - there are several in the 1e DMG, such as the Rod of Seven Parts and The Teeth of Dahlver-Nar. These are plots because the future events - the PCs collect one part, then another and so forth - are right there in the text.
I think the definitions of a plot, a scene,
et al, are being stretched to ridiculous lengths by some in this thread in an effort to prove . . . what, exactly? That those of us who don't write discrete adventures, who eschew conceits related to what we perceive to be a very different medium, are wrong about how we conceive our own games?
As far as citing the examples of modules, I'll ask the same question I did in another thread where EGG was cited as being in favor of fudging: so what? I don't run modules; in fact, I never owned, played in, nor ran
ToEE or
ToH, and neither the Teeth of Dahlver-Nar nor the Rod of Seven Parts ever appeared in any game I ran.
And I find the idea that because an artifact is composed of multiple parts it automatically presumes that some sort of plot is inherent to their use to be the most bizarre definitional stretch of all. A referee could plug one tooth into a treasure horde and leave it at that if she chooses without any assumptions at all about the other teeth.
Perhaps most importantly this "appeal to Gygax" presumes that my goal is to play all roleplaying games the way that EGG advocates. I have tremendous respect for EGG, and I appreciate the games he wrote, but
D&D isn't my favorite game by any stretch of the imagination, nor is my approach to gaming solely predicated on "how Gary did it."