In American Nerd: The Story of My People, Brooklyn-based writer Benjamin Nugent combines a peripatetic history of the word “nerd” with accounts of the various kinds of people it is most often used to describe. The book includes an autobiographical dose; one section called “My Credentials” details Nugent’s early 90s adolescent exodus from d20-style probabilities. On page 3, Nugent fittingly discloses: “when I was eleven, I had a rich fantasy life in which I carried......