L. J. Smith is an author of young adult fiction. She is responsible for creating several related (but not identical) continua, including The Vampire Diaries, The Forbidden Game, and Night World.
The Vampire Diaries is a series about a high school girl, Canon Sue Elena Gilbert, who is the love interest of two vampire brothers, Stefan and Damon. The series follows her story as the two brothers struggle for her affection and Elena is eventually turned into a vampire herself.
The Forbidden Game is a trilogy about a girl named Jenny and her friends. The group find a game that turns out to be all too real as Jenny is stalked by a Shadow Man and the group must escape the Shadow World.
Night World is a series of books about a world where vampires, witches, and other supernatural creatures are real. This series switches protagonists from book to book. Magic and the idea of "soulmates" (one's perfect companion) are central.