If I ever get a chance to write a paper on this aspect of the comic strip for one of my graduate symposiums I will be sure to send you a copy, because I am fairly certain that if I sat down with the entire run (or even a sizable arc), I could come up with lots of things that indicate just that. . .
If you wrote that paper I would be tempted to write another in order to refute it.
There is simply no real justification for thinking that there are players behind the scenes based on the information you get from the strip itself. Every decision made by the PCs is rooted
entirely in their own motivations, goals, and histories. The characters completely lack any kind of metagame awareness beyond the game's ruleset. The characters never show any signs of acting out of character for the sake of achieving player goals. The characters never act on knowledge they should not have. For all intents and purposes the PCs are their own players: Roy's player is Roy himself.
Keep in mind that any metagame knowledge available to the players is equally available to the NPCs. As such, though a PC vs. NPC distinction is made, there is no
functional difference made between the two. For example, Hinjo's status as a PC vs. NPC is impossible to determine at present, and even characters like the Sylph girl severely distort that line. Any such determinations would be merely a guess made by the reader with no evidence to support either way.
This gets even more interesting when you look at the idea of there being a DM. As a whole, there is even less evidence for a DM's existence than there is for the players.
There are a number of details about the game that just don't make sense assuming a "players and DM playing a game" concept. A lot of the stuff about memory wipes and the Oracle's prophecies, for example.
Another factor is that the comic dwells heavily on characters that it would not if this were a game. We see complex interactions between characters like the shadow creature, Redcloak, and O'Chuul that simply would never occur in a real game. These scenes make sense only if you assume the game world is a real, living world (or the DM is a bit touched in the head, which is not what I think Mr. Burlew is aiming at).
Anyways, I can point to a number of webcomics that lean various different ways, both as "the game world is a real world", "the game world is a product of a game", or various hybrids between the two that don't make much sense as either. Actually, most fall into the third, but for reasons that are not a factor in Order of the Stick.
It is a videogame comic, not a D&D comic, but other than two places in the entire comic (both at the very end),
Adventurers! makes the same assumption that Order of the Stick does: that the the characters can act with the same information as a player of the game would, but acts entirely with their own motivations. The divide between "player" and "game character" is simply ignored or removed entirely. This is actually how most of the humor of that comic is derived: pointing out how absurd a player's actions would seem if they were actually presented as a game character's motivation.
