Using the power of stories to create outstanding brands is a common marketing strategy. In recent years, a new marketing tactic, the “underdog brand biography,” has been proposed and used frequently in various industries. This study compares the effects of underdog and top-dog brand biographies on consumers’ brand identification, beliefs, attitudes, purchase intentions, and choices. The experimental results reveal the following: (1) underdog brand biographies can increase consumer brand choices more than top-dog ones can; (2) top-dog brand biographies result in better ad effects for products with high perceived physical risk, while underdog brand biographies produce better effects for products with low perceived physical risk; (3) the comparative effects of the two brand biographies differ across the combinations of brand concept images and the perceived physical risk of the products; and (4) top-dog brand biographies lead to better ad effects through the mediation of brand beliefs, while underdog brand biographies’ ad effects are mediated by brand identification.