One Flew Over the Cuckoo's Nest is a 1975 American drama film directed by Miloš Forman. The film is an adaptation of the 1962 novel of the same name by Ken Kesey. The film was the second to win all five major Academy Awards, (Best Picture, Actor in Lead Role, Actress in Lead Role, Director, and Screenplay) following It Happened One Night in 1934, an accomplishment not repeated until 1991 by The Silence of the Lambs. One Flew Over the Cuckoo's Nest is frequently called one of the greatest films in the history of American cinema. The movie was filmed at Oregon State Hospital in Salem, Oregon, which was the setting of the novel.

 

       Randle Patrick McMurphy (Jack Nicholson), a recidivist criminal serving a short sentence on a prison farm for statutory rape, is transferred to a mental institution in 1963 for evaluation. This is a ploy to avoid hard labor and serve the rest of his sentence in a more relaxed environment. He is anti-authoritarian with a history of violence, but he exhibits no signs of mental illness. McMurphy's ward in the mental institution is run by a calm but unyielding tyrant, Nurse Ratched (Louise Fletcher), who suppresses the patients by employing a combination of subtle humiliation in group therapy, punishment disguised as unpleasant medical treatments and a mind-numbing daily routine. McMurphy finds that the other male and mostly-middle-aged patients are more institutionalized and afraid of Ratched than they are focused on becoming functional in the outside world. McMurphy befriends patients Billy Bibbit (Brad Dourif), a nervous, stuttering young man, Charles Cheswick (Sydney Lassick), a man disposed to childish fits of temper, Martini (Danny DeVito), who is delusional, Dale Harding (William Redfield), a high-strung, well-educated patient and "Chief" Bromden (Will Sampson), a silent 6 feet 7 inches (2.01 m) tall Native American, among others. Believed by the patients and staff to be a deaf-mute, Chief is mostly ignored but is respected because of his size, at which McMurphy marvels at first sight.
       McMurphy baits Nurse Ratched at first merely to amuse himself, but he intensifies his efforts to loosen her control when he sees the effect she has over the ward. McMurphy plays cards with the other patients, acting as dealer and humorously narrating and entertaining them while gambling for cigarettes. This is quickly stopped when Nurse Ratched has cigarettes confiscated and rationed. To break the monotony, McMurphy calls for votes on ward policy changes; he unsuccessfully campaigns for a World Series baseball game to be shown on the television on the ward, and organizes a pickup game of basketball against the orderlies. Then he makes a show of betting the other patients that he can escape by lifting an old hydrotherapy console — a massive and still-connected marble plumbing fixture — off the floor of the ward, and loses, storming out and delivering the line, "Well, at least I tried." McMurphy then learns that Ratched has the power to keep him involuntarily committed to the ward indefinitely, as the more sympathetic ward psychiatrist, while nominally her supervisor, is a figurehead. He accuses the other patients on the ward of deliberately neglecting to let him know this, and learns that they are all voluntarily committed apart from himself, Chief and one other.
        To boost morale on the ward, McMurphy takes the group on a deep sea fishing trip by escaping over the asylum's fence and stealing a school bus, bringing along a party girl, Candy (Mews Small). This is the only location in the film outside the hospital. Rather than have McMurphy transferred, Ratched bides her time and increasingly asserts power, attempting to suppress the now somewhat-liberated patients. Later, McMurphy, the Chief and patient Charlie Cheswick are detained for fighting with the orderlies including Washington (Nathan George) who McMurphy and the Chief despise following one of Ratched's group humiliation sessions. Cheswick undergoes electroconvulsive therapy while McMurphy and Chief wait their turn on a bench. While they wait, McMurphy offers Chief a piece of Juicy Fruit gum, and Chief comments "Thank you". McMurphy is shocked to hear the Chief speak to anyone for the first time in decades, and discovers that Chief shares his distaste of the hospital establishment but stays silent to deflect attention, as given his imposing physical appearance and meek character he does not feel he can rebel in the way that McMurphy does. The Chief becomes McMurphy's confidant, given their shared experiences with authority. After the electroshock therapy, McMurphy stiffly walks back onto the ward feigning catatonia, before humorously animating his face and loudly greeting his fellow patients, assuring everyone that the ECT was unsuccessful as an attempt to subdue him.
One night, McMurphy sneaks into the nurses' station and calls Candy and another lady friend, Rose (Louisa Moritz), and has them bring booze to the hospital. They enter the ward after McMurphy bribes the night watchman, Mr. Turkle (Scatman Crothers). The patients have a party while Billy, who had previously been humiliated by Ratched because of his awkwardness with women, flirts with Candy. At the end of the night, McMurphy and Chief decide to escape and leave with the girls by climbing through a window. McMurphy goes to say goodbye to the other patients, and asks an emotional Billy to escape with them. However, Billy declines, stating that he would like to go on a date with Candy in the future but he is not yet ready to leave the hospital. McMurphy then goads Billy into trying to sleep with Candy, and, although nervous, he agrees. After Billy and Candy go to a private room the rest of the patients, including McMurphy and the Chief, pass out after a long night of drinking.
         Nurse Ratched arrives the next morning and discovers the scene. She orders the attendants to lock the window, clean up the patients and conduct a head count. Billy is found undressed with Candy, and applauded by the other patients as a result. When Ratched scolds him and asks if he is ashamed of his behavior, Billy announces, confidently and without stuttering, that he is not. Nurse Ratched then announces that she is going to tell Billy's mother what he has done. Billy panics and his stutter returns, and after being carried into the doctor's office, he kills himself by slitting his throat. McMurphy, enraged at Nurse Ratched, almost chokes her to death, until one of the male attendants knocks McMurphy away at the last second and she coughs and gasps on the floor.
         After some time has passed, the patients in the ward are shown playing cards and gambling for cigarettes as before, only this time without McMurphy present. Harding, now dealing, mimics McMurphy's narration of the game, while other patients speculate that McMurphy dramatically escaped the hospital rather than being taken 'upstairs'. Nurse Ratched, still recovering from the neck injury sustained during McMurphy's attack, is forced to use a microphone in the nurses' station to be heard by her patients.
          Later that night, Chief Bromden sees McMurphy being escorted back to his bed, and initially believes that he has returned so they can escape together, which he is now ready to do since he feels 'as big as a damn mountain'. However, when the Chief looks closely at McMurphy's unresponsive face, he is horrified to learn that McMurphy received a lobotomy. Unwilling to allow McMurphy to live in such a state or be seen this way by the other patients, the Chief smothers McMurphy with his pillow. Chief then carries out McMurphy's escape plan by lifting the hydrotherapy console off the floor of the ward and hurling the massive fixture through a grated window, climbing through and running off into the distance.