Inspired by Chris Van Allsburg’s 1981 picture book of the same name, “Jumanji” follows the story of Alan Parrish, a boy that gets trapped inside a magical board game for 26 years and emerges as a full-grown man. The film’s star, Robin Williams, felt a deep connection to the movie and Alan’s story as it reminded him of his own life, according to Dave Itzkoff’s “Robin,” a biography of the actor.