Defining the ARG
There's been a lot of renewed discussion on defining what exactly an ARG is, lately. I know this has been touched on here before, but I just want to make a little point on what it seems everyone who's talking is missing. Oh, and lest I be accused of putting ARGs in boxes, I'm talking in terms of the "classic" ARG model as it exists right now, not necessarily what it will be blossoming into in the years to come. I do however think that what I have to say here will still apply then. Time will tell. :)
Most discuss (and rightly so, for the most part) that ARGs are made up of three major componenets: narrative, puzzles, and interaction. Take away any one, and whatever's going on starts to resemble an interactive novel, or a puzzle trail. I would go beyond that and say that, really, the story's the thing. The puzzles and interactions exist as vehicles to propel the storyline.
OK, so here's the subtle yet important point that I think quite a few people continue to miss. It's what Sean Stewart calls Internet Archaeology. I call it Connecting the Dots. The pieces of story are out there for players to find and dig up, not presented in a flow directly to them. The dots are presented to the players, but it's up to them to connect them correctly.
Sean quotes Jordan Weisman, who's #1 assumption about what The Beast (the first ARG in its current form, for the movie A.I.: Artifical Intelligence) would be:
"The narrative would be broken into fragments, which the players would be required to reassemble. That is, the players, like the advanced robots at the end of the movie, would be doing something essentially archaeological, combing through the welter of life in the 22nd century, to piece a story together out of fragments."
An example of this: A series of emails sent to players (or IM sessions) that's merely a journal, or a bunch of exposition, telling the story directly, isn't ARG, it's an electronic novel, which, while enjoyable for some, is definitely not good ARG.
On the other hand, if an email contains subtle clues to things that can be found elsewhere (another website, a password hint, a family member's name, etc.), that's much better. ARGs shouldn't be telling a straight narrative as much as they're delivering the results of said narrative. A series of artifacts that, when put together, reveal what's really going on. The players connect the dots, not the puppetmasters.
This is the most common reason for in-context puzzles. They can easily serve to point to, or unlock, these narrative dots. Sometimes they can point to where they are, or they can serve to be the dots themselves, or both, depending on what the solve is.
The big challenge in all this is determining fun and effective ways to deliver all these dots. How do we tell this story? Sure, a lot of times it's just straight narrative, but it can also take the form of doodles on napkins, audio files, photos, intercepted emails, voicemail, surveillance video, etc.
In Metacortechs, for example, we told the entire story of the underwater resort Aquapolis in a series of incident logs ostensibly generated by its state-of-the-art security and maintainence system. Elsewhere, in a particularly brilliant bit of work by Andy Aiken, a conversation from a broken AI's point of view was told in the form of captured XML code.
Methods like this are much more effective and compelling from a storytelling point of view (not to mention fun for the players) than simply having them find a diary of an Aquapolis worker saying "Today, level 3 flooded for some unknown reason, killing Stavros." or the mysterious robo-guy saying "Bethh.....I...m......brken...Pls....fix.....mee."
Finding things is a lot more fun than being handed things. While the narrative is the heart of the ARG, this Archaeology or Connecting of the Dots is what makes ARG different from an electronic novel, interactive fiction, or what have you.
Take it away, and even if you do have puzzles, narrative and interaction, you have no ARG.