A
series of
books popular during the 1980s. These books were written in
second person narrative (
e.g. "You walk down the hall. You see two doors.") and at the end of each page, or brief section of several pages, the reader was asked to make a decision (e.g. "Which door do you choose, the left or the right?"). Each
choice the reader made led to a different
plot branch, eventually leading to a different ending. These books often proudly proclaimed "20 different endings!" (or however many endings they had) on the back-cover
blurb.
Also used generically to describe copycat series based on a similar structure but set in different genres or settings, such as Dungeons & Dragons, Transformers, and, of course, Zork (whose text-adventure genre probably did much to inspire this type of book in the first place).
Usually the viewpoint character of these books was male, as the books were often targeted at young boys. However, TSR also put out a line of romance novels with girls in mind. To this chronicler's knowledge, the gender of the viewpoint character never stopped interested boys from reading the girl books, or vice versa.
Choose-your-own-adventure books could be considered an early form of hypertext, and hypertext has been used for similar stories since then (apparently including various efforts on the Everything server itself).