The term “plot point” appeared in The New York Times fewer than 10 times during the century or so before 1979. Since then, it has appeared more than 200 times.

This book, published in 1979, was widely regarded over the next three decades as the “bible” of screenwriting.

Syd Field in an undated photo. Mr. Field’s work served as a reference for James Cameron, Judd Apatow, Tina Fey, Frank Darabont and scores of other successful screenwriters

It happens that 1979 was the year Syd Field published “Screenplay: The Foundations of Screenwriting,” a book that over the next three decades became widely regarded as the “bible” of screenwriting, the paperback enabler of Hollywood dreams.

“Screenplay” has sold millions of copies; been translated into more than a dozen languages; served as a reference for James Cameron, Judd Apatow, Tina Fey, Frank Darabont and scores of other successful screenwriters; and inspired plenty of sneers from those who insist that art is born of inspiration, not what Mr. Field, who died on Sunday at 77, argued in “Screenplay” is the crucial stuff of a good screenplay: plot points.

Surrounded by Act I, also known as “the beginning” or “the setup,” and Act III, also known as “the ending” or “the resolution,” plot points are Act II, the moving middle, the decisive developments that propel characters through events dramatic, tragic, comic, nuanced or outrageous. Mr. Field liked the way they kept things rolling in “Chinatown.” And as he updated his book over the years, he had kind words for “Thelma & Louise,” “The Matrix” and the Tom Cruise vehicle “Collateral.”

See for yourself, he would say. Go the movies and look for decisive points of action about 20 to 30 minutes into a film, then look again about 90 minutes into the film.

“It’s an excellent exercise,” he wrote. “The more you do it, the easier it gets. Pretty soon it will be ingrained in your consciousness; you’ll grasp the essential nature of the relationship between structure and story. ”

Many people took his advice, even some who might have initially been reluctant to. Mr. Cameron said “Screenplay” helped persuade him to make films. Mr. Apatow recommended it often. Ms. Fey was the head writer for “Saturday Night Live” but struggled writing the script of her 2004 comedy, “Mean Girls.” Then she picked up “Screenplay.”

“Just to keep a story moving forward was all new to me,” she told The Times in 2004.

“I did a million drafts,” she added. “And I did the thing everybody does. I read Syd Field and I used my index cards.”