A gamebook is a work of fiction that allows the reader to participate in the story by making effective choices. The narrative branches along various paths through the use of numbered paragraphs or pages.
Gamebooks are sometimes informally called choose your own adventure books or CYOA which is also the name of the Choose Your Own Adventure series published by Bantam Books. They can also be referred to as Test Your Fate or TYF which typically refers to a book with many dead-ends.
– from Wikipedia