Three endings were shot, and a different one shown at each theater. All three are included on video. The DVD, however, aside from all three endings, also offers the option to play the movie with one randomly selected ending. In some cities, the newspaper print ads indicated which version ("Ending A", "Ending B" or "Ending C") was being shown at each theater.
According to an interview with writer Jonathan Lynn, after a screening on the 25th Anniversary of the film's release, Carrie Fisher was originally to have been cast as Miss Scarlett, until she ended up in rehab four days before filming started. Lesley Ann Warren was a last-minute substitute.
With the exception of Professor Plum, who wears a blazer and vest in shades of violet, all of the dinner guests wear clothing colors that are the opposite of their respective pseudonym colors on the color wheel. Mr. Green wears a red tie, Col. Mustard (yellow) wears an indigo suit, Mrs. White wears a black dress, Miss Scarlett (red) wears a green dress and Mrs. Peacock (blue) wears a dress and hat in colors of orange and rust.
The screams heard when the characters rush to the maid in the billiard room are not from the actress playing the maid. They are from the actress playing Miss Scarlett, from the scenes where the dead body of the cook and the live body of Wadsworth fall out of the meat locker.
In an interview conducted in November 2009, Jonathan Lynn stated that he had cast the film himself. He said that whilst actors were recommended to him via the casting department, he made the final decisions. His original choice for Wadsworth was British actor Leonard Rossiter, most famous for the role of Rigsby in Rising Damp, but he sadly passed away in 1984 just prior to pre-production. He was followed by Rowan Atkinson, who was well known in England for his roles in Not the Nine O'Clock News (1979) and The Black Adder (1983), but the studio felt he was too unknown to American audiences to be the leading actor in an American production. Ironically, Atkinson would go on to huge success with his character Mr. Bean in America some years later. Jonathan Lynn had known Tim Curry since they were teenagers, and personally asked him to be in the film.
Wadsworth voices the object of the board game after the characters find Mr. Boddy, the board game's only victim, dead. Wadsworth yells "That's what we're trying to find out! We're trying to find out who killed him, and where, and with what!"
Jennifer Jason Leigh, Demi Moore and Madonna were considered for the role of the buxom French maid Yvette. Eager to earn the part, Colleen Camp went to her audition in a French maid costume. In a 2013 BuzzFeed retrospective, director Jonathan Lynn admitted that although he was impressed with Camp's comedic acting skills, it was her well-endowed figure that ultimately convinced him - "There was no avoiding it."
In the opening scene when Wadsworth checks on Mrs. Ho the cook, the live-televised Army-McCarthy hearings are on the kitchen's television. One phrase spoken by Senator Joseph R. McCarthy that can be heard clearly as Wadsworth departs, is "...professors and teachers, who are getting their orders from Moscow..." This Senate hearing is also the same one in which the famous quote of '...Have you no sense of decency, sir, at long last? Have you left no sense of decency?' is spoken by Head Counsel for the Army Joseph Welch. With the coverage of the hearings taking place on live television, the events of the movie take place on Wednesday June 09, 1954.
At the beginning of the movie Wadsworth tells the guests "Of course, since you've each been addressed by a pseudonym you'll have realized that nobody here is being addressed by their real name." In the third ending the characters find that this was true - even for Wadsworth himself.
Only Wadsworth and Yvette see the cook before she's killed. After she rings the gong for dinner, she runs to the kitchen before the characters enter the hall. When she is visible to the dining room in the kitchen, Wadsworth turns his body to cover the cook just in time for Mrs. Peacock to look toward the kitchen.
The song Yvette is dancing to in the beginning of the film, "Shake, Rattle, and Roll," is the version recorded by Bill Haley & The Comets, only it is sped up with the pitch increased. This trick was also used in Airplane! (1980), in which a sped of version of the BeeGees song "Stayin' Alive" is played.
In the US version of the board game, only Professor Plum and Colonel Mustard have any identifiable backgrounds given their titles. In the UK version Reverend Green's profession is also apparent. All of the other characters' backgrounds are left ambiguous. However, on some editions of the board game, the covers show Mrs. White dressed as a maid.
The film takes place in "New England," as revealed in the opening scenes. Soon after, Miss Scarlet is picked up by Professor Plum and explains that she is on her way to Hill House, which is "off Route 41." In real-life New England, there is a Route 41 that spans the northwestern section of Connecticut, continuing through the southwestern section of the Commonwealth of Massachusetts. So, Hill House, story-wise, is located in either of these two New England states.
The role of Wadsworth was written for Leonard Rossiter but he passed away. Rowan Atkinson was considered for the role but was rejected by the studio because he was an unknown in the United States at the time.
The film featured three endings, five bodies, six weapons and seven suspects. This is featured in one of the tag-lines for the film but as there are six murders, one for each weapon, there are actually six bodies not five.
In non-North American editions of the Cluedo board-game such as the UK, Mr. Boddy has been known as Dr. Black, full name Dr. David Black or Samuel Black. The full name of Mr. Boddy in the 2002 US board-game is Mr. John Boddy.
When the evidence of Mr. Boddy's letters of informants and photographs is being stacked to be burned in the fireplace, there is a photograph of Mr. Green with his glasses on leaving a government building and holding a briefcase.
Differences in two weapons in the film include that the revolver in the board game is most commonly a pepperbox revolver (an early 1800s revolver with the six bullet chambers jutting out from the main gun parts). However, it is changed to a regular .38 caliber revolver to possibly keep up with the modern time period the film is set in. The lead pipe in the game was also bent at an angle, to emphasize the fact that it was (possibly) used in Mr. Boddy's murder; the film shows it completely straight.
The New England mansion in the movie, "Hill House," was named after the producer of the movie, Debra Hill. This also has a possibly unintented similarity to the film The Haunting (1963), in which there is a mansion called Hill House that is also located in New England.
During the scene in the kitchen at the beginning of the movie where Wadsworth is checking on dinner, you can see the Senator McCarthy hearings playing on the television. Thus another of the movie's references to the communist scare during the 50's.
The Max Busch House, the mansion used for the exterior and ballroom scenes, was destroyed by a massive fire on October 5th, 2005. After the fire, several people left flowers on the front gate and even shed tears, evidence of how much the house was cherished by the local community.
Significant characters in film that were not in the board-game included Wadsworth the Butler, The Cop, The Cook Mrs. Ho, Yvette the Maid, The Motorist, The Evangelist/The Chief and The Singing Telegram Girl.
There are a few departures from the original board game; in the movie the hall has been transformed into part of the playing board and has been replaced by the front doors. This was probably done so that the rooms didn't have to stand alone.
Actress Eileen Brennan had previously starred in an earlier Old Dark House mystery-comedy. That was about nine years earlier in Neil Simon's Murder by Death (1976), a parody of murder mysteries, where Brennan played Tess Skeffington.
The wrench given to Colonel Mustard during the "Gift" sequence is a Billings & Spencer Co. 12" adjustable "Monkey" Wrench. (Identifiable by the triangle emblem etched into the bottom of the handle, seen when the gloved hand is approaching the Motorist to kill him when he's on the phone.)
When the characters decide to draw lots to search the house, Mrs. Peacock expresses fear that she will be paired with the killer. If the third ending is "what really happened," she and her partner, Professor Plum, are the only killers up to that point. The other pairs are Mrs. White and Wadsworth, who had just said to Mrs. White that "no man in his right mind would be alone together with you"; Yvette and Mr. Green, the only man who was not interested in going with Yvette to the attic; and Miss Scarlet and Colonel Mustard, who suggested the split after seeing the motorist.
While all the other rooms in Hill House were constructed on a sound stage, the room used for the Ballroom was actually located within the house used for the establishing matte shot, 160 S. San Rafael Avenue, Pasadena.
In the early part of the movie, each of the board game characters is given one of the board game weapons in a black gift box. They are as follows Mrs. White - the rope; Mr. Green - the lead pipe; Miss Scarlett - the candlestick; Colonel Mustard - the wrench; Mrs Peacock - the dagger; and Professor Plum - the revolver.
Ironically, the character of Mrs. White was dressed in black, completely at odds with the color perception of the board game's playing piece (though her coat she wears when she arrives is white on the inside). This may be because the maid was dressed in white.
In the credits at the end of the movie, where Clue game cards show pictures of the characters, only three correctly match the character with the weapon they initially received in their gift boxes: Mrs. Peacock is shown with the dagger (which she used to kill the Cook in Endings #2 and #3), Mrs. White is shown with the rope (which she used to kill Yvette in Ending #3), and Mr. Green is shown with the lead pipe (which was used to kill the Cop, but not by Mr. Green). Professor Plum is also shown with the rope, though he never used it during the course of the film or in any of the endings. Miss Scarlet is shown with the revolver, which she did use to kill the Singing Telegram Girl in Ending #1. Colonel Mustard, Wadsworth, Yvette, and Mr. Boddy are not pictured with weapons on their cards. Additionally, the candlestick and wrench are not shown on any of the cards.
There was actually a fourth ending scripted and shot, in which Wadsworth committed all the murders out of a twisted need for perfection in his life. He reveals that he poisoned everyone with a slow-acting toxin in their drinks. It ended with Wadsworth being killed by dogs as he attempted to escape by car from the house. The rather grim nature of the ending is probably why it was never released. It was never shown because the film makers thought the ending would have been too obvious - it only survives in the novelization and the storybook, which features but a single photo from that ending (the Chief punching Wadsworth in the stomach).
When Mr. Boddy pretends to be dead after the revolver is fired in the dark and the six guests try to figure out how he died without having been shot, Wadsworth is missing during the entire sequence in the Study up until he joins the guests in checking on a screaming Yvette in the Billiard Room. Wadsworth's absence was supposed to be intentional because there was a fourth ending filmed where Wadsworth accuses Professor Plum of killing Mr. Boddy and Mrs. Peacock of killing the Cook, but Plum correctly deduces that the reason Wadsworth knows who murdered Mr. Boddy and his five informants (the Cook, Yvette, the Motorist, the Cop and the Singing Telegram Girl, respectively) is because Wadsworth murdered everyone himself. Wadsworth reveals he had poisoned all the guests with a slow-acting toxin he put in their drinks and then he runs to every room in the house that has a working telephone and he rips them out of the wall one by one. He is interrupted when the doorbell rings and is met by the undercover Chief of Police, who disarms Wadsworth with a punch to the gut after Wadsworth attempts to shoot him. The guests tell the Chief and the policemen with him Wadsworth did it all and Wadsworth starts to re-enact to them how he did it, only to slip out of the door and lock them all in Hill House. The police break the Conservatory window to get out with the guests and Wadsworth drives off, only to find the dogs he had at the dog house and Conservatory window are in the backseat and growling at him, about to attack him. The ending was rejected for being too dark and also to keep the film's allowed running time.
In Ending B, where it's revealed Mrs. Peacock murders all six people, it was revealed that Peacock is actually shot dead by the Chief of Police when he confronts her at her car. After saying they got Mrs. Peacock when Wadsworth and the other five guests run outside, the Chief then turns to Mrs. Peacock's dead body and shoots her again. This was deemed too dark and Eileen Brennan recorded a new line saying she's the senator's wife so that Peacock is arrested instead of shot. However, part of the rejected sequence remains in the film: after the police run to Mrs. Peacock to arrest her, you can see smoke in the air from the Chief's revolver as if it had been recently fired.
We learn that Mr. Green is being blackmailed because he is a homosexual working for the government. Later on, J. Edgar Hoover calls the house. In "Ending C" where everyone is guilty, we learn that Mr. Green is really an FBI agent sent in to infiltrate the blackmailer. In a couple of ironic twists, J. Edgar Hoover has long been suspected of being a homosexual and in the 1950's, Hoover started a case called "Operation: Babydoll" in which he gathered intelligence on possible homosexuals working in the federal government.
The line, "Communism was just a red herring," is said in all three endings (twice by Wadsworth and once by Miss Scarlet), and it is a pun. Particularly after World War II, the Russian communists were frequently called "Reds", for example in the anti-communist slogan, "Better dead than Red."
Originally, there were endings in which each character killed off everyone once, and then the ending where they all did it. However, the final cut would have made the movie over two and a half hours, and director Lynn thought it to be excessive, hence the three endings that are in the final cut.
The murders are as follows: (1) The Cook Mrs. Ho in the kitchen with the dagger; (2) Mr Boddy in the hall with the candlestick (his previous demise in the study from the revolver was a false death); (3) The Motorist in the lounge with the wrench; (4) Yvette the Maid in the billiard room with the rope (5) The Cop with the lead pipe in the library and (6) The Singing Telegram Girl with the revolver in the front hall.
In ending C, where everyone but Mr. Green murders a character, only Colonel Mustard (With the Wrench) Mrs. Peacock (With the Knife) and Mrs. White (With the Rope) use the actual weapons they were given as gifts. Plum finishes off Mr. Boddy with Miss Scarlet's Candlestick, Miss Scarlet uses Mr. Green's Lead Pipe for her murder, and Wadsworth/Mr. Boddy, uses Professor Plum's revolver to shoot the Singing Telegram Girl. Mr. Green shoots Wadsworth/Mr. Boddy with a revolver, but it's a gun he's brought with him, and not the weapon given to Plum by Mr. Boddy (The Actual Butler).
In two of the endings (Ending A and Ending B) where multiple people are not the killers, as is the case in Ending C, a woman is the murderer in both, the film connecting with that old maxim, the female of the species being deadlier than the male.