The time period and setting of the film are never mentioned and have been the subject of continuous debate. The electronic devices in this film and its sequels suggest a time period of the late 1800s but Mary Shelley actually wrote the book in the early 1800s. The names of characters and locations seem to be mainly of German origin but the actors are mostly British and speak with British accents.
Ken Strickfaden, who created all the electrical effects for the movie, also doubled for Boris Karloff during the sequences that showed the million volt sparks playing over his body. The same machines were later used in the comedy Young Frankenstein (1974).
A 20-minute test reel, starring Bela Lugosi as the monster and directed by Robert Florey, was filmed on the Dracula (1931) sets. This footage has not been seen since 1931 and is now considered lost. Only a poster, featuring the vague likeness of Bela Lugosi as a 30 feet colossus, remains.
Actor Edward Van Sloan, who played Dr. Waldman in the film, appeared in the now-lost test reel with Bela Lugosi as the Monster. In an interview conducted shortly before his death, Van Sloan remembered that Lugosi's makeup resembled The Golem, with a large broad wig and "a polished clay-like skin." Unfortunately, no footage of the test or any photographs of Lugosi in this makeup are known to exist.
During production there was some concern that seven-year-old Marilyn Harris, who played Maria, the little girl thrown into the lake by the creature, would be overly frightened by the sight of Boris Karloff in costume and make-up when it came time to shoot the scene. When the cast was assembled to travel to the location, Marilyn ran from her car directly up to Karloff, who was in full make-up and costume, took his hand and asked "May I drive with you?" Delighted, and in typical Karloff fashion, he responded, "Would you, darling?" She then rode to the location with "The Monster.".
In rejecting the role of the monster in 'Frankenstein' - a decision he came to deeply regret - Bela Lugosi reportedly claimed the he was a star in his own country, and did not come to America "to be a scarecrow."
After bringing the monster to life, Dr. Frankenstein uttered the famous line, "Now I know what it's like to BE God!" The movie was originally released with this line of dialogue, but when it was re-released in the late '30s, censors demanded it be removed on the grounds that it was blasphemy. A loud clap of thunder was substituted on the soundtrack. The dialogue was partially restored on the video release, but since no decent recording of the dialogue could be found, it still appears garbled and indistinct. The censored dialog was partially returned to the soundtrack in the initial "restored version" releases. Further restoration has now completely brought back this line of missing dialog. A clean recording of the missing dialog was reportedly found on a Vitaphone disc (similar to a large phonograph record). Modern audio technology had to be used to insert the dialog back into the film without any detectable change in the audio quality.
Child actress Marilyn Harris had done several takes of the drowning scene, none of which turned out quite right. Although wet and tired, she agreed to do one last take of the scene, the one that appears in the finished film, after director James Whale promised her anything she wanted if she would do so. She asked for a dozen hard-boiled eggs, her favorite snack. Whale gave her two dozen. The DVD commentary for the film suggests that Harris wasn't actually a good swimmer, quoting Harris as saying that she had only a couple of swimming lessons before filming and had never dived under water before.
The casting of the monster was the most difficult aspect of the casting process. James Whale happened to spot Boris Karloff in the Universal commissary and passed him a note offering a screen-test, which Karloff jumped at. Karloff later joked that he was offended by being viewing as such an ugly character, since on the day that Whale spotted him, he was wearing his most elegant suit and thought he was looking handsome.
According to film historian Gregory Mank, James Whale was jealous of the attention Karloff's monster was getting during production and took revenge by making the actor carry Colin Clive up the mountain to the mill in take after take dozens of times. Clive felt badly for his co-star and suggested that a dummy be used. Whale refused, and Karloff continued to have to carry Clive's six foot 154 body in succeeding takes.
According to the TLC network program "Hunt for Amazing Treasures", a unique six-sheet poster for the original 1931 release, showing Karloff as The Monster menacing Mae Clarke, is worth at least $600,000 US and is possibly the most valuable movie poster in the world. The only known (original) copy is owned by a private collector.
The Monster in this film does not physically resemble Mary Shelley's character. It was make-up artist Jack P. Pierce who came up with innovations such as the Monster's flat head, the bolts through the neck, the droopy eyelids, and the poorly-fitted suit. Any future Frankenstein film that features any of these physical abnormalities is taking its inspiration from Pierce's make-up work.
The popular image of Frankenstein's monster as green-skinned was sourced in this film. Jack P. Pierce's applied a grayish-green greasepaint for the Monster's skin that appeared as a deathly pale gray tone on black and white film. This contrasted with the gray values of the normal characters in the movie. The one exception was the use of a much darker color on the Monster's exposed arm - representing dead, black flesh - prior to it being brought to life.
In one scene, the Monster (Boris Karloff) walks through a forest and comes upon a little girl, Maria, who is throwing flowers into a pond. The monster joins her in the activity but soon runs out of flowers. At a loss for something to throw into the water, he looks at Maria and moves toward her. In all American prints of the movie, the scene ends here. But as originally filmed, the action continues to show the monster grabbing Maria, hurling her into the lake, then departing in confusion when Maria fails to float as the flowers did. This bit was deleted because the censors objected to the violent end of the little girl. This scene is restored in the DVD reissue.
The method of animating the creature is never discussed in Mary Shelley's novel. In the book, Frankenstein, narrating, refuses to divulge how he did it so no one can re-create his actions. However, the use of lightning to resurrect the monster has become the accepted methodology and appears in virtually every Frankenstein movie since.
By the time the ending of the film was changed, allowing Henry Frankenstein to live, Colin Clive was no longer available for additional scenes. For the shot of Henry in long shot in the bedroom behind his father, he was played by another actor; tradition has long held that it was future cowboy star Robert Livingston filling in for him.
As the essential part of the "lake scene" was cut from the film in 1931, theater and later TV audiences were left to wonder how the girl, that was found in the lake actually met her death. Upon restoration of the scene , in the 1980s, on home video and later on Turner Classic Movies (TV), viewers can see what the angry townspeople didn't. Perhaps one might be sympathetic to the monster, in spite of the tragic loss of the child.
In the novel, Frankenstein builds and animates the Monster in what is essentially his dormitory room, and the method is never revealed. Universal decided on the castle laboratory with all the electrical equipment, and this is what the majority of the public now associate with the Monster's creation.
Bela Lugosi was offered the role of the monster, but refused on the grounds that his character would not speak (though he eventually played the role in Frankenstein Meets the Wolf Man (1943)). Lugosi also insisted on creating his own makeup for the Monster, but his design was rejected. According to film historian Richard J. Anobile, Lugosi was originally offered the role of Dr. Frankenstein by original director Robert Florey, but Carl Laemmle insisted that Lugosi play the monster. Test footage of Lugosi in Monster make-up was filmed by Florey on the set of Dracula (1931). Soon after, Florey was replaced by James Whale as director, and Lugosi was replaced by Karloff.
According to The People's Almanac, at one point the movie was to have included a line of dialogue giving the Monster the name, Adam. The Almanac indicates that an early print of this film may have indeed been released with just such a scene, but that it was cut when audiences began referring to the Monster by the name Frankenstein.
Carl Laemmle Jr. offered James Whale a list of 30+ film adaptations he could direct and Whale picked this one. Whale said he did so because he wanted to get away from the war pictures with which he had so far been associated. Ironically, Whale is now, by far, best-remembered for his four horror films.
Extant copies of the 1938 re-issue trailer show The Monster rising from the operating table and stalking away after strangling Dr. Waldman. In the finished film there is a dissolve from The Monster still on the table choking Waldman to The Monster descending the tower stairs.
The trivia items below may give away important plot points.
At the climax, the Monster carries Dr. Frankenstein up the mountain side and through the mill. At the insistence of James Whale, Boris Karloff actually carried Colin Clive in these shots, which were filmed for hours over several days. The 41-year-old Karloff had physical difficulties due to moving in the padding, the back brace that was part of the costume, make-up and 13 pound lifted boots. He badly injured his back during these scenes (and in his 2 subsequent times playing the Monster). Back problems continued to plague Karloff throughout the remainder of his life.
The screenplay originally called for Henry Frankenstein to die from his fall from the burning mill. When Universal decided for a happy ending (see "Alternate versions"), Colin Clive was in England, so his stand-in was used for the far shot of him recuperating in his bed, with his fiancée at his side.