Harry, Ron and Hermione learn about the Deathly Hallows, legendary items that lead to mastery over death. In interview, Rowling has stressed that these two quotations 'sum up – they almost epitomize the whole series'. Rowling also wrote an 800-word prequel in 2008 as part of a fundraiser organised by the bookseller Waterstones. Librarian Nancy Knapp pointed out the books' potential to improve literacy by motivating children to read much more than they otherwise would.

Meeting secretly with a small group of students who name themselves 'Dumbledore's Army,' Harry teaches them how to defend themselves against the Dark Arts, preparing the courageous young wizards for the extraordinary battle that lies ahead. On 12 April 2023, the series was confirmed to be in development, and will be streamed on the new streaming service Max (formerly known as HBO Max). They steal a Horcrux from Gringotts and travel to Hogwarts, culminating in a battle with Death Eaters. The final instalment in the series, Harry Potter and the Deathly Hallows was released in two cinematic parts: Part 1 on 19 November 2010 and Part 2 on 15 July 2011. They have attracted a wide adult audience as well as younger readers, and are widely considered cornerstones of modern literature.

However, the assumption that Harry Potter books have increased literacy among young people is "largely a folk legend". Themes such as normality, oppression, survival, and overcoming imposing odds have all been considered as prevalent throughout the series. When Umbridge bans practical teaching of Defence Against the Dark Arts, Harry, Ron and Hermione form " Dumbledore's Army", a secret group to continue the teachings. Time magazine named Rowling as a runner-up for its 2007 Person of the Year award, noting the social, moral, and political inspiration she has given her fandom.

The first releases of the successive books in the series followed in the same style but somewhat more realistic, illustrating scenes from the books.The attacks appear related to the mythical Chamber of Secrets and resemble attacks fifty years earlier. In 2003, four of the books were named in the top 24 of the BBC's The Big Read survey of the best loved novels in the UK. Personalized advertising may be considered a “sale” or “sharing” of information under California and other state privacy laws, and you may have a right to opt out. In 2007, Rowling composed seven handwritten copies of The Tales of Beedle the Bard, a collection of fairy tales that is featured in the final novel, one of which was auctioned to raise money for the Children's High Level Group, a fund for mentally disabled children in poor countries.