The humanoid alien protagonist of the film, Klaatu (Michael Rennie), instructs Helen Benson (Patricia Neal) that if any harm befalls him, she must say the phrase to the robot Gort (Lockard Martin).

"[2] Edmund H. North, who wrote The Day the Earth Stood Still, also created the alien language used in the film, including the phrase "Klaatu barada nikto".

[3] Klaatu uses it near the beginning of the film to shut down Gort, and again at the end, highly distorted and barely audible, when he stops the destruction of the Earth.

Skoble observes that this theme has evolved into a "staple of science fiction that the machines charged with protecting us from ourselves will misuse or abuse their power.

"[8] Film historian Steven Jay Rubin recalled an interview he had with North when he asked the question, "What is the direct translation of 'Klaatu barada nikto?'

'"[9] In accepting the AFI Life Achievement Award in 1998, Director Robert Wise closed his remarks by saying, "...I'd like to say 'Klaatu barada nikto', which, roughly translated tonight, means 'Thank you very much from the bottom of my heart.