Nancy Drew is a fictional character appearing in several mystery book series, movies, video games, and a TV show as a teenage amateur sleuth. The books are ghostwritten by a number of authors and published under the collective pseudonym Carolyn Keene. Created by the publisher Edward Stratemeyer as the female counterpart to his Hardy Boys series, the character first appeared in 1930 in the Nancy Drew Mystery Stories series, which lasted until 2003 and consisted of 175 novels. Over the decades the character has evolved in response to changes in American culture and tastes. Beginning in 1959, the books were extensively revised and shortened, partly to lower the printing costs, with arguable success. In the revision process, the heroine's original character was changed to be less unruly and violent. The Nancy Drew franchise has been adapted into other forms of media with varied success. As of April 2020, the character has been adapted into six feature films, three television series, four television pilots, 33 video games produced by the brand HeR Interactive, and two different comic book series. Film and television adaptations of the character have been met with mixed reviews, while the video games by HeR Interactive have often been lauded. The character proves continuously popular worldwide: At least 80 million copies of the books have been sold, and the books have been translated into over 45 languages.