The Sting is a perfectly performed con game—even the audience is ultimately conned. The film starts in Chicago with a couple of grifters, Johnny and Luther, conning a courier carrying money that was meant for the hands of a high level crime boss, Doyle Lonnegan.
After their big hit, Luther decides it is time to retire. He gives Johnny the name of a grifter legend who taught him all he knows and who could teach Johnny. Initially Johnny scoffs at this—learning from this guy AND the idea of Luther retiring.
The slight on Lonnegan cannot be let go without challenge to his power. So Lonnegan’s people take out Luther and go after Johnny. And Johnny ends up seeking out Luther’s old friend, Henry Gondorff, the grifter legend.
Gondorff does little to initially impress Johnny who finds him drunk and caring for a carousel at a red light establishment. Gondorff comes around to the idea of scamming Lonnegan with a sting to end all stings, and Johnny comes around to trusting him.
And we get to see a network of drifters at work. Gondoroff calls on old contacts to set up the ruse. They build a fake horse racing gambling house and commandeer a Western Union office.
A Chicago cop—portrayed as corrupt and incompetent (it is 1936 after all)—continually is on the hunt for Johnny, sporadically crossing paths with him. The cop becomes an unwitting accomplice to the plot to swindle Lonnegan out of half a million dollars.
As part of the plot, Johnny interacts with Lonnegan who has no idea that this is the guy he has his goons out trying to kill. Twists occur in the movie with presumed killers being protectors and spoilers of the plot being participants in it.
In the end, the sting goes off as planned. The audience is not in on the entire plot. Lonnegan himself never catches on. The movie is a wonderful chance to see Newman and Redford together.