This instalment of my series on interactive narrative focuses on branching.

In many respects, branching narratives represent the opposite end of the spectrum to traditional linear narratives.  Branching narratives are the most common attempt at truly unconstrained and interactive drama where the player’s behaviour materially influences the conclusion.

Instead of a single continuing storyline, branching narratives offer the user consequential choices.  Each decision offers a unique path in an ever-diversifying array of events.  Although the total outcomes will be finite, branching narratives give the user control over the course of the action.  Rather like changing the points on a railway line, branching narratives allow the user to determine the direction of the train, and therefore its destination, but not the path between points.  The game designer determines all the available options but the user decides the route through them.

branching narrative

In a truly branching narrative, every decision has a unique set of consequences.  This reflects real life where every choice provokes an avalanche of outcomes where future options are a direct result of an individual’s behaviour.  There are circumstances in reality when an individual’s choice is illusory and just as when this occurs in real life, the facade of control in games is quickly obvious and deeply unsatisfying.  The opportunity to genuinely choose the path of discovery offers the user real control but every true option generates at least two outcomes.  The combinatorics quickly become unmanageable from a production perspective.  Even offering the minimum of two choices per decision at each stage the number of outcomes multiples exponentially, according to the simple equation o = 2^s where S is the number of stages.  For example, it is clear that three stages result in eight possible outcomes.

Obviously, with this method of interactive drama, as well as effort required to generate each possible path, there is a large amount of redundancy – the user only explores one of the total number of paths through the material (n), this means every user misses the majority ((n-1)/n*100%) of the content unless he revisits the story multiple times.  Revisits can offer rewarding alternatives and genuinely new insights into the game world but this assumes that each option is equally well thought out and credible.  It’s not just the practicalities of production that make true branching difficult, it is extraordinarily hard to generate multiple outcomes that offer an equivalent level of satisfaction from an cognitive-emotional point of view.  It can feel as though each alternative outcome dilutes the quality of the conclusion for the user with some endings just plain disappointing.

constrained branching

The key differences between the branching narrative of a computer game and the chaos of real life are richness, flexibility and predetermination.  In life, there are no certainties of outcome or total control over parameters – it is intrinsically unpredictable.  Games, on the other hand, are, at the current time at least, entirely human constructs with little, if any artificial intelligence.  Every decision and outcome is, if not totally predefined, the consequence of predetermined models and rules.  The constraints of the production mean that narrative cannot be entirely free.  Instead, producers regularly draw the narrative back to shared nodes.  These nodes appear as the consequence of possibly unrelated decisions and provide a means of limiting the range outcomes.

If you’ve ever read a Fighting Fantasy book or Leila Johnston’s Enemy of Chaos, you’ll be familiar with arriving at the same point from multiple directions.  It’s a methodology that works – it’s not entirely free but the balance of control and storytelling is enough to satisfy.

Parallel narratives next…

The whole Interactive Narrative series is:

• Linear narrative
• Parallel narrative
• Non-linear narrative
• Branching narrative
• Dynamic narrative
• Simultaneous narrative