The Darth Vader poster represents Jared’s gradual coming-of-age journey over the course of the book. The poster first appears at Jared’s friends’ house, which is called Powder House. The cardboard cutout of Darth Vader greets people at the door, and the image depicts the Star Wars villain holding a skateboard alongside a thought bubble that reads, “POWDER HOUSE RULES.” Thus, in its introduction, the poster represents a playful innocence: first, it depicts a character from the Star Wars franchise, whose viewership is largely made up of kids and teenagers. Second, its message suggests a carefree recklessness—freedom from adults and, likewise, adult concerns.
Over time, however, the poster gradually disintegrates, reflecting how Jared is growing up and away from adolescence. After his friends move away, Jared brings the poster back to his basement bedroom and hangs it on the ceiling, where the poster develops cobwebs on its feet and begins to peel away from the wall. This reflects how Jared’s adolescence is slowly decaying as well, as he faces adult problems like helping to care for his elderly neighbors, paying his dad’s rent, and dealing with his mom’s abuse and neglect. By the end of the book, Darth Vader vanishes from Jared’s basement completely, and he wonders how he missed the poster’s disappearance. This suggests that, likewise, Jared has grown up without fully realizing it—a gradual process, but one that becomes finite by the end of the book when Jared demonstrates his own maturity by getting sober, finding a job, and accepting his true identity as Wee’git’s son.