MacGuffin

In fiction, a MacGuffin (sometimes McGuffin) is an object, device, or event that is necessary to the plot and the motivation of the characters, but insignificant, unimportant, or irrelevant in itself.

[1][2][3][4][5] The term was originated by Angus MacPhail for film,[2] adopted by Alfred Hitchcock,[1][2][3][4][5] and later extended to a similar device in other fiction.

"[9][10] The World War I-era actress Pearl White used the term "weenie" to identify whatever object (a roll of film, a rare coin, expensive diamonds, etc.)

impelled the heroes and villains to pursue each other through the convoluted plots of The Perils of Pauline and the other silent film serials in which she starred.

[14][15] Hitchcock explained the term MacGuffin in a 1939 lecture at Columbia University in New York City: It might be a Scottish name, taken from a story about two men on a train.

[20] In contrast to Hitchcock's view, George Lucas believes that "the audience should care about [the MacGuffin] almost as much as the dueling heroes and villains on-screen.

[26] Examples from Hitchcock's films include plans for a silent plane engine in The 39 Steps (1935), radioactive uranium ore in Notorious (1946), and a clause from a secret peace treaty in Foreign Correspondent (1940).

"[31] A similar usage was employed in John Carpenter's Escape from New York, where the protagonist Snake Plissken is tasked with rescuing both the President of the United States and a cassette tape that will prevent a devastating war between the country and its enemies.