New Line Cinema forced Alex Proyas to include the opening narration by Kiefer Sutherland, which gives away several plot reveals. Proyas objected to it, saying it was unnecessary, and he subsequently removed the narration from his director's cut.
On the DVD commentary, co-writer David S. Goyer reveals two possible explanations for the origin of the inhabitants of Dark City. In his original story outline, director Alex Proyas believed the humans to have been passengers aboard an interstellar spaceship which was captured by the Strangers. Goyer favors a more spiritual approach, supposing that the humans are in fact dead and that Dark City is a sort of purgatory made up of people the Strangers have selected or abducted from different eras in history.
The name of Kiefer Sutherland's character, Daniel Schreber, is the same as that of an author of an early twentieth century book entitled "Memoirs of My Nervous Illness". He wrote it while he was institutionalized for schizophrenia, originally as an argument for his release. The book has become standard reading for many psychiatrists and psychologists, and many of the theories of both Sigmund Freud and Carl Gustav Jung were based on it (Freud never actually met Schreber, though). "Dark City" borrows heavily from the concept of "fleetingly-improvised men" which are found within Schreber's "Memoirs".
An over-sized version of Dr. Schreber's syringe (roughly a meter long) was built for the close up shots of the needle being extended so that its surface details would be visible in the focal plane of the camera lens.
The movie appears to take place in the late 1950's/early 1960's. Cars and clothing appear almost exclusively from that period. Also, in the flashback of Keifer Sutherland's character being forced to erase his own memory he's seen wearing an old-style medical smock favored by doctors of the period. This reinforces the idea that he was a kidnapped psychiatrist being used by the aliens to manipulate human memory.
(at around 10 mins) The music which Inspector Bumstead is playing on his accordion in his very first scene in the movie is a song written in 1939 by a Polish-Jewish composer Jerzy Petersburski which was originally called "Mala blekitna chusteczka" ("Little Blue Handkerchief"). The lyrics were later translated (with slight differences) to many languages and it became especially popular in Soviet WWII era under the title "Siniy Platochek" ("Blue scarf"). The song lyrics tell about an unhappy, lonely man who wanders aimlessly around the world thinking about his lost love which is gone forever. His only memento of his beloved one is the blue handkerchief from the title. As the movie is about our memories, the song actually fits the movie mood quite well.
Although Alex Proyas wrote the original screenplay, very little of the plot was retained (besides the fact that the lead is wanted for murders) . Lem Dobbs wrote the final draft and reformed the plot as it appears in the film with the exception of the special effects sequences. Although the powers of the Strangers were alluded to they would never actually be depicted . David Goyer was hired to write the shooting script when they had secured a bigger budget. He added all the action scenes that appear in the film and which show explicitly the operating background of the Dark City.
The song from the film's trailer is "Sleep Now" by Hughes Hall. The song was also used in the trailer for Full Moon's 1998 horror movie "Talisman" that was produced by legendary B-movie filmmaker Charles Band.
American heavy metal band Iced Earth has a song titled Dark City that is directly inspired from the movie. The song is from their 2011 release Dystopia and features lyrics like, Experimenting to understand the human soul endangered they'll fade away and Fill our heads with false identity synchronizing our confusion.
The trivia items below may give away important plot points.
(at around 1h 16 mins) According to Director Alex Proyas commentary on the Director's Cut DVD, test screening audiences were "troubled" by the notion that the entire city wasn't sucked out into space once the Shell City Wall was breached. Thus, a last minute SFX addition of Bumstead and a Stranger drifting through a force field was created.
This film deals with 'Last Thursdayism', a philosophy described in a satiric comment by 20th-century historian Bertrand Russell, referring to the "Omphalos" papers (1857) of Philip Gosse. Last Thursdayism says that the world (with us and our own basic memories included) could have been created recently, even last Thursday, but we cannot demonstrate such a thing because the world would have been created to look like an older world.
Near the end of the film, there's a shot of Jennifer Connelly (Emma/Anna) at the end of a pier looking at the ocean. This shot was repeated in Connelly's later films "Requiem for a Dream" (2000), and "The House of Sand and Fog" (2003).
(at around 2 mins) At the beginning of the film, there is a brief shot of the movie theatre which says "Now Showing, The Evil, Late Show Nightly" and to the right, "Coming Attractions, Book of Dreams" (a previous film by Alex Proyas). At the end of the movie the marquee still says Book of Dreams: 'Welcome to Crateland' (1994) is coming soon, even though the theater and marquee have changed.
The first draft of the script by Alex Proyas was vastly different from the finished film. It includes the appearance of the Strangers, the setting of a perennial Dark City, and the fact that John Murdoch is wanted for a series of murders that he does not recall committing. Notable aspects of the initial script include an evil robotic puppy accompanying the Strangers (which would attack savagely with its steel jaws) and a climactic trial for John Murdoch. The reanimated corpses of the victims would testify against Murdoch in the trial, and even John's wife would be a witness.
Both Jennifer Connelly and William Hurt played in two Hulk movies respectively. Jennifer played Betty Ross in the Ang Lee version. While William played General "Thunderbolt" Ross in the Incredible Hulk.
(at around 14 mins) According to the list that Bumstead shows to Emma, the names of Murdoch's victims are Michelle Davies, Alison Montgomery, Samantha Richards, Kathleen O'Shea, Simone Shaunessy and Beth Mulligan.