SAN FRANCISCO — Bringing a scholarly take to trashy literature, the First District Court of Appeal ruled Friday that state prison officials can’t stop an inmate from reading an erotic romance novel built around human-werewolf relationships.

The Silver Crown by Mathilde Madden may describe graphic sexual encounters and contain a fair amount of violence, but it is not legally obscene under state and federal standards, Justice James Richman wrote for a unanimous First District panel.