The stories are formatted so that, after a couple of pages of reading, the protagonist faces two or three options, each of which leads to more options, and then to one of many endings. The number of endings is not set, and varies from as many as 44 in the early titles to as few as 7 in later adventures. Likewise, there is no clear pattern among the various titles regarding the number of pages per ending, the ratio of good to bad endings, or the reader's progression backwards and forwards through the pages of the book. This allows for a realistic sense of unpredictability, and leads to the possibility of repeat readings, which is one of the distinguishing features of the books.