Storytelling and interactivity are a challenging mix. In most games your actions as a player directly conflict with the plot, and your immersion disintegrates. Sam Fisher single-handedly killing entire armies without a glint of regret; Niko Bellic lamenting his criminal past while absent-mindedly reversing over a prostitute's head; Max Payne shrugging off shotgun wounds by necking a few painkillers. It's often hard to think of these characters as real people.
This is not the medium to tell realistic stories, unless the gameplay is grounded in reality - which it never is, because reality is boring and makes for a terrible game. Unlike film, where a director has control of every frame, in games your actions can totally change the mood and meaning of what's happening on screen.
"The central character of a game is most often a cipher - an avatar into which the player projects himself or herself," says John Spaihts, co-writer of Ridley Scott's film Prometheus. "The story has to have a looseness to accommodate the player's choices. This choose-your-own adventure quality is a challenge for storytellers."
"A filmmaker is trying to make you look at something a certain way. Think of the legendary directors whose perspective is the soul of their art. It's the opposite of a sandbox world. Storytelling in games has matured tremendously in the past decade, but the design requirements are almost the opposite of filmic storytelling."
The actual process of designing a game is the biggest hurdle for a writer. The production cycle is long, unpredictable, and constantly evolving. Entire levels can be dropped at the last minute, leaving a gaping hole in the narrative that the writer has to fill. If a level is cut that explains how a character got from one place to another, the writer will have to explain it some other way, and somehow still keep the narrative flowing naturally.
It's a gruelling process, and they have one of the hardest jobs in the industry, as Naughty Dog's Amy Hennig, lead writer on PS3's Uncharted series, explains: "You can't just write a script and say, 'Let's go make this.' Within five minutes of development, it's out of date. We only loosely plan the story, which is the best you can do with something as iterative as game design."
A lot of mainstream developers have become so obsessed with aping films that the game inside suffers
"I write game scripts a scene at a time, out of sequence, over the course of a year. You have to be able to see the entire web of the project in your head, which changes from day to day because of the realities of the production. Development and writing becomes a communal act of faith, which is a hard thing to sustain."
So if a plot doesn't work, or feels unnatural, it's not just the writer's fault. The very nature of games, and the way they're made, makes telling a story difficult. The medium is also in its infancy as far as narrative goes. While there are thousands of books about how to write for TV and film, there are few guides to writing a videogame. Contemporary games writers are the pioneers of a completely new form of storytelling, and they're the ones who will be writing the guidebooks for the next generation of developers.