Several commentators have noted that personal identity is a strong theme in the book and that it addresses issues of racism through the treatment of non-human, non-magical, and non-living people.

Some commentators regard the story's diary that writes back as a warning against uncritical acceptance of information from sources whose motives and reliability cannot be checked.

Video games loosely based on Harry Potter and the Chamber of Secrets were also released for several platforms, and most obtained favourable reviews.

The Weasley brothers Ron, Fred, and George arrive in their father's flying car and take Harry to their home.

When Harry and the Weasleys go to Diagon Alley for school supplies, they meet Gilderoy Lockhart, a celebrity author who is the new Defence Against the Dark Arts professor.

Argus Filch's cat is found Petrified, along with a warning scrawled on the wall: "The Chamber of Secrets has been opened.

Harry learns that the Chamber supposedly houses a monster that attacks Muggle-born students, and which only the Heir of Slytherin can control.

[1] In early drafts of the book, the ghost Nearly Headless Nick sang a self-composed song explaining his condition and the circumstances of his unknown death.

"[3] Gilderoy Lockhart's character was inspired by an acquaintance of Rowling who was, in her words, "even more objectionable than his fictional counterpart" and "used to tell whopping great fibs about his past life, all of them designed to demonstrate what a wonderful, brave and brilliant person he was.

[13] In The Times, Deborah Loudon described it as a children's book that would be "re-read into adulthood" and highlighted its "strong plots, engaging characters, excellent jokes and a moral message which flows naturally from the story".

However, he enjoyed the parody of celebrities and their fans that centres round Gilderoy Lockhart, and approved of the book's handling of racism.

[17] Mary Stuart thought the final conflict with Tom Riddle in the Chamber was almost as scary as in some of Stephen King's works, and perhaps too strong for young or timid children.

[18] According to Philip Nel, the early reviews gave unalloyed praise while the later ones included some criticisms, although they still agreed that the book was outstanding.

[23] In 1999, Booklist named Harry Potter and the Chamber of Secrets as one of its Editors' Choices,[24] and as one of its Top Ten Fantasy Novels for Youth.

[21] Harry Potter and the Chamber of Secrets won the Nestlé Smarties Book Prize 1998 Gold Medal in the 9–11 years division.

[17] Riddle also complicates Harry's struggle to understand himself by pointing out the similarities between the two: "both half-bloods, orphans raised by Muggles, probably the only two Parselmouths to come to Hogwarts since the great Slytherin.

"[31] Opposition to class, death and its impacts, experiencing adolescence, sacrifice, love, friendship, loyalty, prejudice, and racism are constant themes of the series.

[34] Although Bronwyn Williams and Amy Zenger regard the diary as more like an instant messaging or chat room system, they agree about the dangers of relying too much on the written word, which can camouflage the author, and they highlight a comical example, Lockhart's self-promoting books.

[38] In his article "Harry Potter and the Secular City", Ken Jacobson suggests the Ministry as a whole is portrayed as a tangle of bureaucratic empires, saying that "Ministry officials busy themselves with minutiae (e.g. standardising cauldron thicknesses) and coin politically correct euphemisms like 'non-magical community' (for Muggles) and 'memory modification' (for magical brainwashing).

"[30] This novel implies it begins in 1992: the cake for Nearly-Headless Nick's 500th deathday party bears the words "Sir Nicholas De Mimsy Porpington died 31 October 1492".

[41] Some objects that play significant roles in Half-Blood Prince first appear in Chamber of Secrets: the Hand of Glory and the opal necklace that are on sale in Borgin and Burkes; a Vanishing Cabinet in Hogwarts that is damaged by Peeves the Poltergeist; and Tom Riddle's diary, which is later revealed to be a Horcrux.