STORY:
In 1963 Oregon, Randle Patrick Mcmurphy (Nicholson), a criminal who has been condemned to a genuinely short jail term, chooses to have himself proclaimed crazy so he'll be moved to a psychological organization, where he hopes to serve the remainder of his term liberated from jail work and in (relative) solace and extravagance.
Nurse Ratched (Fletcher), a ruthless tyrant who has coerced the patients (most of whom are "voluntary" or there by choice) into dejected institutional submission, runs his ward in the mental institution. With Nurse Ratched, McMurphy becomes involved in a number of power games in an effort to win the patients' hearts and minds. Constantly, be that as it may, the inquiry is exactly how rational any of the players in the ward truly are and whether they truly have a place there.
McMurphy develops friendships with his fellow patients throughout his time at the hospital, but two in particular forge the strongest bonds: Billy Bibbit (Dourif), a self-destructive, stammering manchild whom Ratched has embarrassed and overwhelmed into a shuddering wreck; and "Chief" Bromden (Sampson), a Native American man of 6 feet, 5 inches who suffers from schizophrenia. He is regarded as deaf and unable to speak by the ward patients, who not only respect him for his enormous size but also ignore him. McMurphy sees a younger brother figure in the former that he wants to teach to have fun, and the latter is his only real confidant because they both know what it's like to be coddled.
When Chief first enters the ward, McMurphy insults him, but he also tries to take advantage of his size by playing basketball, where his height helps. Mac decides to oppose Ratched and attempt to undermine her authority as much as possible when he observes the patients' submission under her tyrannical control. McMurphy suggests during a counseling session that the ward's work schedule be changed so that patients can watch the World Series on TV. Mac wagers on whether he can lift the marble water-treatment control panel in the ward and throw it through a window to escape and watch the Series at a bar when the first meeting is stopped by Ratched. Despite his extreme effort, he naturally fails.
When Ratched makes the announcement that a majority vote will be acceptable, the subsequent discussion regarding changing the work detail quickly degenerates into a battle of wills. However, Ratched swiftly alters the rules to stipulate that votes must be taken from the Chronic and Vegetable patients when he realizes that the vote may favor McMurphy. When the vote doesn't go in McMurphy's favor, he starts to think the game is on TV and rallies the majority of the other patients to support him, causing a big uproar.
McMurphy drives the patients in a ball game against the ward's orderlies. Chief Bromden excels as a player, scoring numerous points. McMurphy disregards the objections of the orderlies, who assert that the patients are engaging in dishonesty. Mac learns from an orderly that he will not be released from prison at the end of his sentence; rather, he will remain in the hospital for as long as the board and Ratched deem necessary, as the patients later unwind in the hospital pool.
One more directing meeting follows and McMurphy, extremely irritated with the methodical's disclosure, figures out that he's been recorded as a "committed" patient and might be delivered when Ratched grants it, a profoundly far-fetched situation. Additionally, Murphy discovers that many of the patients in the ward are there on their own accord: They are free to leave at any time, but Ratched's dominance prevents them from doing so. McMurphy seems particularly irritated by Billy's voluntary stay on the ward when he could be free and enjoying his youth.
However, when an angry patient named Charlie Cheswick raises the issue of Ratched's cigarette rationing, the session quickly degenerates into violence. After McMurphy introduces Blackjack to nearly all of the patients who play cards, Ratched is forced to limit how many cigarettes he smokes. Ratched tries to restore order when Taber is violently and loudly dragged away after being burned by a lit cigarette. Charlie also suddenly becomes hostile, and a fight breaks out with the orderlies. Mac, Bromden, who had rescued one of the orderlies from Mac, and Cheswick are taken to a detention area where disruptive patients receive electroconvulsive therapy. Cheswick is sent first to go through ECT, while McMurphy and Boss look out for the seat. McMurphy gives Chief a piece of gum in the few moments they have together, and Chief thanks him verbally. McMurphy discovers, to his surprise, that Chief can speak and hear him and has feigned illness throughout. McMurphy takes steps to permit Boss in on his getaway plan in light of his secret insight. Towards the end of the scene, a more obstinate McMurphy approaches an awaiting Nurse Ratched from the detention area. Mac says he'll happily rejoin the group again and gives the impression of being submissive.
Nearing Christmas, McMurphy, fed up with Ratched's oppressive tactics, sneaks into the nurse's station at night and calls Candy to bring alcohol and help him escape. She brings a sweetheart, and both enter the ward when McMurphy persuades the ward's night chaperon, Mr. Turkle, to open one of the ward's gotten windows. Billy flirts with McMurphy's girlfriend while the patients consume a lot of alcohol. The party gets very loud, which gets Turkle's boss's attention. Until Turkle can convince the supervisor that only Candy is hiding in the office, he hides them all in Ratched's office.
The party continues. Billy, irritated by Mac's departure, suggests to Mac that he wants a date with Candy later in the evening, just as McMurphy and the Chief prepare to finally leave. Billy receives a private room with Candy, and Mac encourages Billy's confidence and allows him to have sex with Candy. McMurphy, on the other hand, falls asleep with the other patients while he is waiting, believing that the encounter will be brief.
Nurture Ratched and the orderlies show up in the first part of the day to find the patients snoozing and loomed over and the ward and her office destroyed. However obviously resentful and irate, she smoothly orders the orderlies to lock the open window, escort Sweets' companion out of the medical clinic and direct a head count. Ratched demands that the others reveal Billy's location when they discover that one patient is missing. Billy and Candy are found, and they are immediately taken out of the hospital.
Billy must reveal to Ratched who allowed him to have sex with Candy. Billy, his falter recognizably gone, tells her that McMurphy did, and that the remainder of the ward empowered him. After that, Ratched, passively enraged, threatens to tell Billy's mother, citing their longtime friendship. Billy quickly resumes his stutter, and he begs Ratched not to tell his mother because he is so upset. He cries and is dragged screaming to Dr. Spivey's office when she explains that he should have considered the consequences. McMurphy, still holding Turkle's keys, opens one of the windows and prepares to flee when Miss Pilbro, Ratched's nurse assistant, screams loudly.
McMurphy and every other person hurry to Spivey's office. He took his own life by cutting his throat with a sharp piece of glass after being left alone for a while. McMurphy explodes into a violent rage and viciously strangles Nurse Ratched after seeing what the ward has done to his friend and hearing Ratched's instructions for everyone to remain calm and return to their routine. She makes it through, but McMurphy is taken off the ward after being knocked unconscious by an orderly.
McMurphy's fate will be talked about around the ward for the next few weeks. He appears to have been lobotomized, despite the fact that some people believe he escaped. McMurphy is quietly returned to his bed by orderlies one late night. When the Chief sneaks up on Mac, he finds him unresponsive in his bed; In addition, he observes Mac's two lobotomized scars on his forehead. The Chief suffocates his friend McMurphy, who looks like a vegetable, with a pillow because he won't leave McMurphy behind. He hurls the heavy marble hydrotherapy fountain through a barred window and escapes to Canada, something Mac had previously been unable to do.
