Zimmerman on narrative coherence

One of the hardest things to do with interactive plots is to write it so it makes sense in whatever order the player or user accesses the text. Plot is about cause and effect, and so having lots of possible points-of-entry is hard to design for. I just read a short piece by game designer Eric Zimmerman on a graduate school experiment he did years ago, where he explains how he tackled the problem.

“Life in the Garden” is an “interactive paper book” — box set of cards with text and images. You shuffle them in any order and reading them produces a coherent narrative. In the essay he wrote for Second Person [PDF], Zimmerman describes the strategies he used:

Appropriating Eden
The garden of Eden is a set of characters, situations, themes, and ideas that are incredibly pregnant with meanings and possible interpretation. Members of the cast (Eve, God, Adam, the serpent, and the occasional anonymous angel) can be invoked without resorting to backstory exposition. By writing into a story-world that already exists, I take advantage of the reader’s presumed knowledge of that world, and the personal meanings that the reader brings.

Strategic Writing
Creating the text for Life in the Garden was part story-writing part building-block design.  Like a set of LEGO bricks, the pages are modular, and must work well in any configuration. Any individual page needs to be able to function as a first page, as an ending page, or as something in the middle. At the same time, the content of the pages must add up to an expressive and varied experience.

Thematic Coherence
Part of the “sense” of a Life in the Garden story results from a limited number of content themes that are repeated often. Sleeping and dreaming, the time-based processes of nature and their inevitable decay, and the mythologized origin of writing and naming occur throughout the pages. Chances are that in any given story, themes mentioned on some of the pages will overlap.

Size Mix
The pages are a set of ingredients for a procedural stew, and the parts had to be balanced to result in a properly variegated texture each time. My playtesting process resulted in a very specific ratio of “short” one-line pages, “medium” pages with two or three lines, and “long” pages of several lines. Themes and content were also parsed carefully into the mix. For example, by only including a handful of genuinely perverse incidents (such as the serpent crawling up Adam’s anus) these pages retain their pleasurable surprise, even upon repeat reading.