FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
Linear Stories
From the earliest days of computer gaming, designers have been intrigued by the idea of agency: letting the player influence the plot and change the outcome.
Game developers refer to stories that the player cannot change as linear stories and those that the player can change as nonlinear stories. The next section addresses nonlinear stories.
A linear story in a video game looks similar to a linear story in any other medium, in that the player cannot change the plot or the ending of the story. In a game, however, the player still faces challenges as she goes through the story, and in fact the challenges form part of the story itself. Thus, a linear story in a game is still an interactive story, but the player's interactions are limited to contributing actions. Still, many games use this format. Consider Half-Life and StarCraft: Both tell linear stories, the outcome of which the player cannot change, but the player performs many actions as part of the story along the way.
Creating linear stories offers many advantages, which explains why, after a flurry of experimentation with nonlinear ones in the 1990s, the game industry largely returned to this practice. Linear stories do have disadvantages as well, however. Here are some of the pros and cons to consider when designing your own story.
■ Linear stories require less content than nonlinear ones. If a player can only ever experience one fixed sequence of events, you only need to create material for those events. Developing the game using a linear story requires less time and money.
■ The storytelling engine is simpler. The storytelling engine managing a linear story has to keep track of only a single sequence of plot events. Because the player cannot change the course of events, the storytelling engine doesn't need to record critical decisions that the player makes: There aren't any. The storytelling engine will be easier to implement in software if you use a linear story.
■ Linear stories are less prone to bugs and absurdities. If the sequence of events remains the same regardless of players' actions, you can guarantee that the story makes sense. On the other hand, if you allow the sequence of events to vary—that
is, you present a nonlinear story—you introduce the risk of error. The storytelling engine must guarantee that the events make sense. If the player wrecks a car during play in a game with a nonlinear story, the storytelling engine must ensure that the game does not present any subsequent gameplay or narrative material that shows the car undamaged. If you're not careful, you can introduce what the film industry calls continuity errors: things that look different from the way they should look, given the events of preceding scenes, because narrative material can't change to keep up with game events. Linear stories don't incur this risk. If a car is wrecked as part of the story, it stays wrecked; if it mustn't be wrecked, then you must not give the player any way to wreck it.
■ Linear stories are capable of greater emotional power. From a creative standpoint, this is one of their greatest advantages. The section "Emotional Limits of Nonlinear Stories" explains this point in more detail later in this chapter.
Note that if you want to tell a strictly linear story, that decision will have consequences for any story you plan to treat as a journey (as many are). See the section "The Story as a Journey" later in this chapter.