Fey does not take the book too seriously, finding plenty of cruel humour in the bitchy battles between Cady and Regina.

One of the movie's achievements is persuading the audience to stay firmly in Cady's camp during her odyssey of self-discovery.

This teen comedy is terrific. Superbly scripted by Saturday Night Live head writer Tina Fey, it explores the viciously divisive cliques that render the American high school a virtual battleground.

The film’s relevancy has stood the test of time with not only its iconic quotes just at the tips of our tongues, but because the team behind it crafted something truly special with its snappy script and prolific performances.