Packard wrote the first known book of this type, Sugarcane Island, in 1969, and arranged for it to be published in 1976 by Vermont Crossroads Press, owned by Constance Cappel and Raymond A. Montgomery, Jr. Packard explains in the foreword to the book that he developed what he originally called "the adventures of you" fiction format while trying to think up interesting bedtime stories for his three children (Caroline, Andrea, and Wells).
Because at the time the format was so unusual, readers were warned at the outset not to read the book straight through, but to follow the pages corresponding to their choices.
Packard wrote the first book in the Bantam series, The Cave of Time, a time-traveling story in which the reader explores a cavern that is a portal to different eras.
[10] Packard was the only CYOA author who included a recurring character in many of his books: a scientist, Dr. Nera Vivaldi, frequently appeared in the role of a friend to the reader.
Seemingly ageless, she appears in stories set in many different time periods, including those that take the reader into outer space.
In Hyperspace, Dr. Vivaldi breaches the fourth wall by acknowledging that she is a fictional character whom the reader may recognize from having read other CYOA books.
[11] Beginning in 2012, Simon & Schuster released revised and expanded print versions of selected Packard CYOA stories: Through the Black Hole, Return to the Cave of Time and The Forbidden Castle, under the trademark "U-Ventures".
He also wrote a non-fiction book about the size and scale of space and time, titled Imagining the Universe, which was published by Berkley in 1994.