FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
Foldback Stories
Foldback stories represent a compromise between branching stories and linear ones. In a foldback story, the plot branches a number of times but eventually folds back to
a single, inevitable event before branching again and folding back again to another inevitable event. (These are also sometimes called multilinear stories.) This may happen several times before the end of the story. See Figure 7.3 for a simplified example. The Secret of Monkey Island follows this format, as do many of the traditional graphic adventure games.
Most foldback stories have one ending, as shown in the figure, but this isn't a requirement. You can construct a foldback story that branches outward to multiple endings from its last inevitable event.
Foldback stories offer players agency but in more limited amounts. The player believes that her decisions control the course of events, and they do at times, but she cannot avoid certain events no matter what she does. She may not notice this the first time that she plays and may think that the story reflects her own choices at all times. If she plays the game more than once, however, she will suspect that some events are inevitable and that the apparent control she enjoyed on the first play-through was an illusion. This is not necessarily a bad thing and can be useful to you as a storyteller. There's no reason why an interactive story must offer the player a way to avoid any event that she doesn't want to experience. After all, stories have always included the occasional event that the protagonist can do nothing about. If Scarlett O'Hara could have prevented Atlanta from being burned in Gone with the Wind, the story would have had a very different outcome and lost much of its emotional power. It's reasonable to use inevitable events to establish plot-critical situations that the player cannot reasonably expect to prevent or change.
The foldback story is the standard structure used by modern games to allow the player some agency without the cost and complexity of a branching story. Developers routinely construct the interactive stories in adventure games and role-playing games as foldback stories. Of all forms of nonlinear interactive storytelling, it is the easiest to devise and the most commercially successful.
If you want to create a foldback story, you should choose critical turning points in the plot to be the inevitable events. They need not always be large-scale events like the burning of Atlanta. They simply should be events that change things forever and from which there is no turning back. The hero facing his final challenge, for instance, or the death of an important character, both work well as inevitable
events. Obi-Wan Kenobi's death, in Star Wars IV: A New Hope, works well as an inevitable event.
