A little background: During my years at BioWare, I found that despite the enormous amount of talent housed in the writing department, there were certain subjects for which we lacked a common language of craft -- a clear and broadly applicable way to discuss what worked, what didn't, and why. This article is an effort to remedy that problem for one particular subject.

Due credit goes to my former BioWare colleagues Cameron Harris (now of ArenaNet), who provided feedback on my notes for a previous iteration of this article; and Daniel Erickson (now of Bluepoint Games), who reviewed a near-final version and suggested I take it to Gamasutra. Thanks to Greg Rucka as well, whose blog posts on character arcs in Mass Effect helped inspire elements of this discussion.

Part One: Introduction and Definitions

Let's start with the basics.

Stories -- traditional stories, archetypal stories -- are about protagonists who go through difficult circumstances and who change or resist change because of those circumstances.

The change can be positive or negative. The protagonists can be heroic or villainous. The circumstances can be dramatic or humorous. Sometimes the "change" isn't so much a change of nature as it is the gradual unveiling of true character and motivations. But while there are exceptions, the sweeping statement above covers most stories pretty well.

Star Wars is about a farm boy who's caught up in a galactic war that pushes him to find the inner strength he's always lacked. Breaking Bad is about a science teacher who engages in an enterprise that changes him from an underachieving family man into a criminal mastermind. Friends is a sitcom about a group of young adults who are forged by the tumult of their jobs and personal lives into more comfortable, confident, mature members of society.

Most video games (particularly decision-based RPGs such as Star Wars: The Old Republic, Mass Effect, Deus Ex: Human Revolution, Alpha Protocol, et al, which are this post's focus) are, structurally speaking, very traditional narratives. An RPG typically features a single protagonist throughout who makes difficult choices under trying circumstances.

Yet many RPGs fail to deliver a compelling character arc for the protagonist. The reason is clear enough: When a player is given control over the protagonist and the choices he or she makes, that player isn't (and shouldn't be) focused on the storytelling craft of generating a dramatic arc. Instead, the player is engaged in the moment, fulfilling whatever fantasy or aspiration drove the player to buy the game in the first place ("I want to be cool like James Bond" or "I want to be the scariest criminal around.")

It's very likely that the player will make the same sorts of choices throughout the game -- the player who starts playing Mass Effect as a heroic Commander Shepard who frowns on human xenophobia is probably going to make mostly positive Paragon choices throughout -- unless given a reason otherwise. The player who begins Deus Ex: Human Revolution as a brutal killing machine is doing so because that's the character he or she is keen on playing. Why would the player even want to change?

That's fine, of course, but it limits the nature of the story being told. There can be no tragedy, redemption, growth, or catharsis when a player unthinkingly maintains the same approach throughout a story. Nonetheless, I believe a transformative character arc is very much achievable in a branching narrative RPG, and results in a highly rewarding experience.

So if most players aren't ordinarily inclined toward change -- if players act as change-resistant human beings, not authors of a script looking to generate the most drama -- how do we develop a genuine character arc? And how do we dramatize the protagonist's inner life in such a way that the arc isn't merely in the player's imagination, but grounded by clear in-game results?

How do we change a game from a thought experiment ("I want to be a good guy soldier") to a genuinely immersive exploration of character?