From IFWiki

What Aristotle called "the arrangement of the incidents," the plot of a work depends upon how its episodes are presented. A work of IF may have only one possible plot, as in Photopia. It may have several plots, as in Losing Your Grip. Most cave-crawl adventures have multiple plots because they have puzzles that can be solved in a different order each time. Although a work like the usual play or novel can be said to have a plot, a work of IF has one or more potential plots that are only realized during an interaction.

-- nm - 15 Jul 2002