Now that I've looked at how Dungeons & Dragons is an example of a transmedia property -- or at the very least, similar to it -- I can get to the good stuff. What can an understanding and experience with D&D teach us about writing for transmedia? Start With a Rich Storyworld
Many transmedia writers have talked about this to great extent: a transmedia property isn't about a single story in a static medium. You can't get away with only knowing as much as you need to for one storyline. For a transmedia property, you need an entire storyworld that you can build many different stories within.
This is true of D&D just as much. Published campaign worlds like Forgotten Realms or Eberron need to be fully realized settings that allow DMs and players to create and tell hundreds, thousands of stories within. You might set up a particular location as the default starting point of a story campaign, but you can't assume everyone will use it. Every location in the world needs to be rich with potential for stories.
This holds true as well if you, as a DM (transmedia producer, property creator) create your own world. There's a lot of frontend work you need to do to make your world a fully realized, living place. Even if you know exactly where the player characters start and where you expect them to go, you need to have at least an idea of what's going on around that. For one thing, it adds an element of verisimilitude -- even if you don't expect the king's succession problems to figure in the plot, when the players hear rumours of it in the tavern, they get a sense that they're in a real, working world (instead of a two-dimensional movie set).
photo © 2008 Dave O | more info (via: Wylio) Building on the movie set metaphor, you also can never be sure what your players are going to do at any given time. They may veer off your planned path (more on this in later installments) and if you don't have your world fleshed out, they'll see the two-by-fours holding up the building facades. Suddenly, they'll find themselves in a place that seems far less real than where they were before, and the sense of immersion is lost.
And that's the key. If there's enough detail of the world in which the players are playing (the world that the audience is exploring in a transmedia property), it will seem far more real, and thus allow them to become immersed in it and the story. There's nothing worse than someone who is immersed turning a corner, finding a blank wall and being torn out of the story.
Potential for Stories
I mentioned this briefly, but it's worth looking at in more detail. When you're creating a world for a transmedia property, just as when you're creating a world for D&D, you need to consider the potential for stories -- the potential to expand in the future. You may know the main story of your property -- the driving platform, for instance -- and know what parts of your world you need to understand for that story. But the worst thing you can do is create that and then realize you've written yourself into a corner and can't expand it into other media, other stories.
But that means you do need to consider the potential for transmedia from the top. Tacking on transmedia after the fact is a recipe for disaster. Know your full story world and the potential within it; know the rules of your world and stick to them -- the audience of transmedia will find inconsistencies if they exist. Note that I don't think you need to know every single story within that world from the top -- just know where the potential for those stories are so you can successfully build them later.
I've run D&D campaigns before where I had only the briefest sketch of the world, the immediate setting, and a couple adventure ideas, without having fleshed out the world or where I was going with the story. I may have been able to run some interesting encounters, but a couple months into the campaign, I suddenly found myself scrambling to work in a story that wasn't there at the start. I had to hand-wave some continuity changes, and insist that elements of the world were always present, just not noticed.
With enough good improv, this can work, but it's a flimsy construct at best. A savvy audience will see through it immediately.
If, on the other hand, you've seeded in the workings of the world from the start, then when they suddenly become improtant, your storytelling mastery will pull your audience in and engage them that much more.