Procedural Narrative: Sorcery and Magic

I’d like to talk for a bit about procedural narrative, which has been an important feature (probably the central feature) of the GearHead series since its inception. But first, a song.

By the time this gets to you the language will be nonsense,

words all lose their meaning by the time they leave the tongue.

Sometimes ain’t about making the whole world understand you;

words just speak for moments like the light speaks for the sun.

The Bourbon tabernacle choir, “by the time”

Procedural narration is the use of a computer program to help make up a story. According to at least two separate people, GearHead Arena (2002) was the first game to successfully incorporate procedural narrative (I’m sure I could find a third person if I asked around on Twitter). The effect of procedural narration is that no two playthroughs of GearHead Arena are the same. Different events will happen; characters who were your friend one time around might be your enemy next time. From the player’s perspective each story is both unique and coherent.

The definition of procedural narrative that I gave in the previous paragraph is a bit broad so I’m going to split it in two. And, being an English professor, I’m going to use a metaphor to do it. Most people approach procedural narrative as a matter of technology. They look to AI projects like GPT-3 for an algorithm that can produce meaningful texts. I’m using “text” here in the broad way that English professors use the word- in this case, the story of a computer game can be a text. This technique can produce interesting and useful results. The game AI Dungeon, for instance, is a simulated game master that creates a story in response to user actions. I’m going to refer to this technique as sorcery. It involves calling upon powerful algorithms that the programmer can never fully understand and has limited direct control over (in this case, a trained AI system). It’s not unlike a sorcerer calling upon a genie (daemons, alas, are a completely different type of software).

I don’t do sorcery. I do magic.

As everybody knows, or at least as everybody who studied literary criticism in the mid 90s knows, the meaning of a text is not contained entirely within the text. Instead, meaning-making is an active process performed by the receiver of a text. When you read a book your brain reconstructs the meaning not just from the words on the page, but also from your cultural background, your preconceptions, your dialect, and a million other factors that affect how you see the world. This is one reason why different people can have different interpretations of a text. It’s also a reason why texts from different times and places can be difficult to understand, or may have a different meaning here and now than was originally intended by the author. The same is true of computer games.

GearHead Arena uses a technique that is now pretty standard for procedural narrative. The story is constructed from a series of plot fragments, each of which describe something that could happen. The plot fragments themselves are mostly self-contained; they don’t need to communicate with other plot fragments. The story generator strings the plot fragments together such that each fragment logically follows from the fragment before it. It doesn’t worry about the story as a whole just as long as each individual transition makes sense. It is the player’s brain that constructs a coherent story from these disparate pieces. This is magic. It’s an illusion- trickery!- but an illusion that relies on the willing participation of the audience. The computer isn’t really creating a story; it’s just sorting bricks according to a set of mechanical rules. But that’s not what the player sees. The player sees a living world, a place they can interact with and change. What they don’t realize is that they are the co-creator of this world.

The whole thing is very similar to Scott McCloud’s theory of how closure allows a reader to see two comics panels and combine them into a single story.

McCloud, Scott, 1960-. Understanding Comics : the Invisible Art. New York :HarperPerennial, 1994.

It is not about the technology; it is about the performance. That’s the difference between sorcery and magic. Almost every time I’ve explained GearHead’s procedural narrative algorithms to a programmer they’ve been amazed (sometimes disillusioned) by the simplicity. You can read more about Markov Chains and Propp’s Ratchet in other posts on this blog.

GearHead Caramel, the latest game in the GearHead series, uses more advanced techniques to string plot fragments together but it’s still just another magic trick. I only hope that you continue to enjoy my performance.

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