A while ago I was downloading the remaining sondtrack for Portal 2, a game that's still on my list for game of the year. (The fact that I actually wanted the soundtrack to a game should tell you something of the production values and creativity of the team involved). I thought about the story, trying to determine what made it so much better than the typical video game fare. This was shortly after I'd listened to Writing Excuses' podcast on the Hollywood Formula, and approaching the issue from this angle showed something interesting

I should note that if you haven't already played Portal or Portal 2, this post assumes you know how the story goes, and there are major plot spoilers ahead. I'd strongly suggest that if you have any intention of playing it (and you should), play it before reading any further. It's well worth it, and one of the few games where experiencing the story is a vital component to the game.

The first thing to notice is that Chel – the player-character – doesn't have an emotional arc. Hell, she doesn't even have a personality. She has a goal, certainly – freedom, which, let's face it, is mostly there for player direction; there's nothing waiting for her out in the real world anymore – but other than that, there's nothing of 'her' communicated to the player. She's a blank slate, a vehicle for the player, a point-of-view. She can't speak, can't emote or gesture, can't do anything to evoke an emotional response from the player. She is, essentially, an empty vessel. Her job is to carry the player to the game, and then get the hell out of the way.

Not all player-characters are like this – most games strive to imbue the player with their characters' purpose and emotional concerns, and to some extent – a very limited extent – this works, but nowhere near the extent that it does it books or even movies. We're not really driven to care about the character's lost son or wife the way we would a novel protagonist's. It's understood that player-character story is mostly there to tell us what to do in the game, not evoke and emotional response.

Most of the time, all you see of Chel is the portal gun. If you look down, even her feet are invisible. In fact, I found a moment at the end quite affecting, when Chel is stripped of the gun and, injured, looks at her empty hands. I felt a moment of profound vulnerability and connection, suddenly remembering that my vehicle through the game was meant to be human. For the most part, Chel is just you, the player, within the game.

When we look at this from the Hollywood Formula, something interesting happens: Chel isn't the protagonist. Oh, she's the one controlling the action, the one propelling the story forward, but it's not her story. She has no arc, no emotional experience. One could argue the protagonist is Wheatley – striving to release Chel from her prison and combat Glados. But though his arc from incompetence to betrayal (and even more incompetence) is certainly more than Chel's, he never really changes from the experience.

In fact, the protagonist is Glados – the one we would normally mark as Chel's antagonist. She has a goal – to continue her testing – which runs counter to both Chel's goal of escape and Wheatley's goal to take over the facility. She discovers remarkable depth in herself through her depose-ment and subsequent potatofication, and the discovering of Caroline and the reason for her existence.

Wheatley opposes her at every turn: guiding Chel through the facility, overriding the security protocols and finally convincing Chel to replace Glados with him – upon which the role reversal is near-instantaneous. He plunges Chel back down to testing, consigns Glados to a potato, and completes the zenith of his arc as the even-worse-villain-than-the-bad-guy when he resolves to kill Chel. His defeat by Glados (the final defeat is not actually by Chel – she just enables) cements him as the antagonist to Glados' protagonist. So where does that leave Chel?

Chel – the player – is the relationship character for Glados. From initially loathing each other (or, at least, Glados loathing Chel – Chel did kill her twice, after all) they form a kind of bond while working together to rid the facility of Wheatley and in doing so, hopefully save themselves – though quite intentionally, little mention is made of what will happen once that goal is achieved, and Glados (presumably) restored to power.

Glados learns to be “human”, discovering Caroline within her, to the point that she actually saves Chel from being spaced, and is worried about her wellbeing when she is injured in the final battle. While she chooses to delete Caroline and return to her former personality, she still resolves to release Chel rather than kill or imprison her. The moment of reconciliation and understanding (defining relationship character moment) occurs as Glados returns to the “normal” (Campbell) world of her unemotional self in control of the facility: she makes a different choice that in an almost identical moment at the start of the game, a choice in favour of her former enemy, without the malic that was present earlier.

While Glados makes a convincing rational argument (that the easiest solution is usually the best, and releasing Chel is much easier than killing her) we can see she still retains some of Caroline in her final “gift” of the companion cube, rescued from the death Chel/we had been forced to consign it to in the first game. This is the final reconciliation between the characters.

You can also make the argument that Chel is the relationship character for Wheatley – they work together, he betrays her, tries to kill her, but after he's defeated he apologises. Chel doesn't actually witness this apology, but she doesn't really have to – we have, in her place. In the structure of characters, the player and Chel are essentially the same entity.

For a long time, when considering potential game stories for my partner's games, I have run up against the difficulty of giving the player-character an emotional arc that the player would actually give a damn about. The player can never invest the way a 'real' character would, nor can you control their emotional state and reactions the way you would a novel or movie protagonist, so all but the most delicate of manipulation usually falls flat.

This apparent solution – shifting the emotional arcs onto the non-player-characters and – this is a crucial part – building those arcs as a direct result of the player's actions in the game, might be the start of a promising direction in game story. While it's certainly not the only direction, it's a technique that clearly works in games (and equally clearly, is highly unlikely to work often in other media – a clue that perhaps it's taking something closer to the right approach for an interactive media) and, I hope, may form the basis for further exploration in narrative structure and communication.