Acting for Two: Charles Fleischer voices not only Roger Rabbit but Benny The Cab and the Toon Patrol's Greasy and Psycho. Veteran voice actress June Foray provides the voices for both Wheezy and Lena Hyena.
Warner Brothers only allowed Disney to use their iconic characters if they got exactly the same amount of screen time as Disney's, hence the Donald Duck/Daffy Duck duel, and the Mickey Mouse/Bugs Bunny scene. The two Ducks' piano duel ends in a draw, with it being unclear who even started the fight, and Bugs and Mickey both try to dissuade Eddie from taking the spare because it's not a spare parachute but a spare tire. Tropes Are Not Bad; these scenes were some of the funniest in the movie (although there was Creator Backlash from Chuck Jones on the pianos).
It also works out better that way because this is exactly what people wanted to see, It's not enough to just have them in the same movie, you want to see them actually interacting with one another.
There were also some individual, quick sequences with one character, such as Dumbo, Yosemite Sam, and Tweety. The length of these scenes were probably under a lot of scrutiny as well in order to not show favoritism towards one company.
It's also worth noting that Porky Pig and Tinkerbell share the last bit of the movie.
A persistent rumour also claims that the reason the film's title has no question mark at the end of what is presumably a question (Who Framed Roger Rabbit?) is that the executives vetoed it after a focus group came back with results suggesting that audiences were wary of movie titles containing overt questions.
Keep Circulating the Tapes: The German TV version is probably the only print in the world that has the original version of that scene (and the original scene of Baby Herman sticking his finger out while walking underneath a live-action woman's skirt and gazing up it lecherously. The new version keeps the scene in, but digitally removes the finger). The older versions are out of print.
In Memoriam: Disney Channel ran the movie to pay tribute to Bob Hoskins (who passed away on April 30th, 2014).
Method Acting: Charlie Fleischer requested a full-body Roger Rabbit costume to wear as he fed his lines to Bob Hoskins off-screen to help stay in character. He reportedly got picked on a lot by the animators working on The Great Mouse Detective at the time, who assumed that the 'toons were all just going to be actors in shabby costumes.
Name's the Same: Lena Hyena shares her name with Lena the Hyena, a recurring character in the comic strip, Li'l Abner. Whether or not Lyena was inspired by the Li'l Abner character is undetermined. In either case, even the hideous Jessica decoy can rest easy knowing she isn't the ugliest Toon out there when compared to the Li'l Abner"character"◊.
Playing Against Type: Christopher Lloyd as Judge Doom. This one of the few movies where he plays a truly evil and ruthless villain, although this was made around the same time as most of those other films.
Suffice to say, a lot of young people wanted to become animators after this movie.
Betty Boop also had a brief revival in her popularity thanks to this movie.
Stillborn Franchise: That sequel has been stuck in development hell long enough to see both the rise of computer animation as a dominant medium and the downfall of traditional feature animation in the United States that it's safe to assume it's not going to happen at this point. In fact, it may be the most financially successful movie ever made to not receive a sequel. That said, there have been other non-movie works about Roger, including comic books, and Gary Wolf's book series has continued.
An animated example: in one shot, Bob Hoskins' eyeline was a bit off, resulting in him looking at a two-foot-too-tall Roger. This was rectified by having Roger stand nervously against a wall on his tip-toes.
To a lesser extent, the term "bump the lamp", named for the scene in the speakeasy when Eddie, handcuffed to Roger, keeps bumping his head on a hanging lamp, requiring special attention to Roger's shadows, became shorthand for when animators wanted to push their animation a little further. However, Gary K. Wolf confirmed on his Facebook that, contrary to popular belief, it was not an actual term used in production—screenwriter Dan Wolf coined the phrase for a speech he wrote for Michael Eisner well after the films release.
Eddie Murphy also turned down the role of Eddie. He said in an interview that he regrets it to this day.
Bill Murray was an early favorite of both Spielberg and Zemeckis for Eddie, but, as Murray is notoriously difficult to contact, they were unable to get ahold of him. Murray claims that had he known, he would have taken the part.
John Cleese expressed interest in playing Doom, but both Steven Spielberg and Robert Zemeckis refused thinking nobody would take a former member of Monty Python seriously as a sadistic villain. Roddy Mc Dowall, Eddie Deezen, Sting, and Jon Pertwee were all considered as well.
Terry Gilliam was initially offered the director's chair, but he felt the film was too technically challenging, a decision he regrets, stating that it "was pure laziness on my part."
One of the early drafts of the film called for Jessica's act to have a cameo of Tex Avery's Wolf to be seen doing similar reactions during Jessica's performance at the ink and paint club. Sounds like this would have been a tribute to Tex Avery's Red Hot Riding Hood, his best known MGM cartoon.
Or did he? It turns out that, according to new footage obtained from an '80s special titled Disney Studio Showcase, producers originally wanted Reubens to voice Roger. Reubens was quite a bit okay voicing the character... for a while. Besides that, it was also revealed that originally Jessica Rabbit was hardly in love with Roger at all
In an early draft of the script, it would be revealed that Judge Doom was actually the hunter who killed Bambi's mother.
Which may have been intended to be a Mythology Gag from the original novel, which contained a throwaway line implying Bambi really did have a mother who was murdered by someone.
This scene would happen after Eddie left Roger at the bar and before he snuck into Jessica's dressing room. The scene would have also included Eddie seeing R.K. Maroon and Doom talking to each other which further raised Eddie's suspicions of Maroon being involved.
Originally there were twelve weasels. These were cut down to seven (to mimic the seven dwarfs)note The other two were named Sleazy/Flasher and Slimey, and finally five, to give them a more prominent role in the movie.
Also, in the early script, toons weren't immortal and could get killed by any kind of attacks like in the book. This, too, was changed to the fact that toons can only be killed by the Dip.
According to Chuck Jones, due to Executive Meddling the piano duel you see in the film is not the original storyboarded version. While it is a memorable scene, who knows how hilarious the original must have been?
In a scenario lifted from classic Looney Tunes cartoon "Show Biz Bugs", all of the audience's praise would have gone to Donald Duck, who'd do absolutely nothing but standing there to receive such acclaim, as Daffy Duck could only gain the attention of Chirping Crickets no matter how hard he tried. In a movie meant to showcase the zany and wild nature of 40's cartoons, you can see how this scenario really didn't fit with the film's atmosphere.
Besides, Donald getting acclaim for anything would've gone against his own character. Having Daffy and Donald sabotaging each other not only fit the movie better, it fit better with Donald and Daffy as characters.
The sequel would've had Eric Goldberg supervise the animation instead of Richard Williams. He was heading the animation test that they showed Michael Eisner to prove they could still pull it off without William's London studio. But the results did not satisfy him, and the other reasons listed in the opening section attributed to its cancellation. ...just imagine every single classic cartoon character with the movement of Aladdin's Genie! Eric Goldberg would eventually head another film with the Roger Rabbit Effect in Looney Tunes: Back in Action for 2003.
In the third draft of the script, instead of Doom dipping the shoe, he was to dip a gopher for bumping into him and soiling his coat. When the gopher complained that he should get a trial first, the weasels take out a briefcase containing a literal Kangaroo Court and call him guilty, with their joeys holding card spelling "Y-O-U-A-R-E-G-U-I-L-T-Y", followed by the gopher getting dipped as Eddie helplessly watched.
Judge Doom was originally going to have an animated pet vulture named Voltaire (after the French philosopher) that sat on his shoulder, but that idea was dropped in the interest of saving time. However, the vulture later resurfaced with Doom when a bendable action figure was produced.
Jack Angel was going to be in the movie as the voice of Captain Cleaver, a tough, gruff Toon human police captain from Toontown and the head of the T.P.D. Homicide Division, who would have been very combative with Eddie in terms of who's going to solve the Acme case.
Gary Wolf, the original author, was offered to do a Creator Cameo numerous times (mainly because he was present during filming most of the time). He turned the offer down due to being very camera-shy at the time (it's also why he's rarely present in behind-the-scenes documentaries or specials concerning the film). He mentioned though on his Facebook page once that, had he been up to it at the time, he would have pitched the idea of him playing a crazed fanboy trying to get Jessica's autograph, only to get carried away by bodyguards.
According to the early original script, the working title was Who Shot Roger Rabbit?, basically because it revealed the manner of how Roger would die before the title was eventually changed, as the studio would not want a character's death to frighten children.
Other possible titles: Dead Toons Don't Pay Bills, Murder in Toontown, Toons, The Toontown Trial, Eddie goes to Toon, and Trouble in Toontown.