Creator Backlash: Director Sam Raimi called the film awful and stated: "I tried to make it work, but I didnt really believe in all the characters, so that couldnt be hidden from people who loved Spider-Man." Producer Avi Arad apologized for forcing Raimi to put Venom in the film. Raimi also really hated the Executive Meddling that forced him to have Mary Jane simply be a Damsel in Distress yet again, after hed promised Kirsten Dunst it wouldnt happen.
Deleted Role: Adrian Lester filmed a cameo as a scientist that Marko visits that was cut.
Deleted Scene: Part of the scene where Peter looks at his reflection in a mirror after returning to his apartment after seemingly killing the Sandman was cut. The cut segment would have shown Peter looking down at the Black Suit under his clothes, then looking up to see his reflection as Venom, which explains him locking the Black Suit away immediately afterwards with an alarmed expression on his face. The Venom model that was used harkened back to the character's original appearance, without fangs or distorted eyes.
Executive Meddling: The reason Venom and Gwen are in it (though Eddie Brock was always planned, just not his alter-ego).
Venom and the entire symbiote arc weren't supposed to be in the movie at all. Instead Sandman was supposed to team up with Vulture, who would be his cellmate that vowed revenge against Spidey after being busted by him. Vulture was supposed to be played by Ben Kingsley. Also, rather than being forced to break up by Harry, Peter and MJ would break up naturally after several bad decisions by both. However, studio executives forced Sam Raimi to bring in Venom, a character he was both unfamiliar with and uninterested in, because they thought the character would get more money from audiences. This interference lasted throughout the entire production, leading to several deleted scenes like Harry being talked out of his revenge by Mary Jane rather than his butler, Gwen being kidnapped since Eddie is convinced Peter loves her rather than MJ being kidnapped yet again, Sandman's daughter showing up and talking him out of the final fight, Eddie actually seeing Marko's situation with his daughter rather than knowing it out of nowhere, and others. This meddling is also the reason why a Spider-Man 4 was never made. Raimi and executives just could not agree on a script that would satisfy both parties, so Raimi left.
Kirsten Dunst only agreed to reprise her role in the 3rd film on the condition that Mary Jane would not end up as the Damsel in Distress. Executives agreed. MJ was originally going to have a more proactive role in the film's climax (Gwen was going to be the damsel while MJ would be the one to talk Harry into helping and forgiving Peter; her lines from this scene remained in the trailer). When the plans changed, they made sure MJ was an Action Survivor during this particular distress as means of making it up to an upset Dunst. Throwing a cinderblock at Venom was thrown in, they let her jump and swing on hanging webs herself before needing to ultimately get saved, and any of MJ's screams during the scene (Peter's too, for that matter) were recycled audio. On the audio commentary, Raimi tells a rough story of coming to the process that in order to finish the movie on time, they had to put MJ in danger, which not only angered himself for reneging on his promise to Dunst before production started that he wouldn't, but that summoning the courage to tell her was one of the hardest things he's ever done in his long time in the business.
Franchise Killer: For Sam Raimi's Spider-Man Trilogy. The whole reason Raimi left the proposed Spider-Man 4 (which, in turn, ended up getting it cancelled) was because he didn't feel as though he could make that film not like this one within the given amount of time.
In the Mexican Spanish dub, Liliana Barba replaced Claudia Motta as Mary Jane and Ismael Castro replaces Jesse Conde in his cameo role for Stan Lee as Conde has already voiced Norman Osborn in the series.
The Editor's Cut of the film necessitated a completely re-dubbed Latin American adaptation, this time recorded in Argentina.
Sam Raimi's daughter is the little girl with the camera who sells it to JJ.
The Ugarte siblings appear in various roles in the Mexican Spanish dub. Xóchitl voices Gwen Stacy, Víctor voices a man talking about the Daily Bugle's apology to Spider-Man, and Gaby voices Penny Marko and the little girl with the camera.
Show Accuracy/Toy Accuracy: Many of the Venom figures from Hasbro (such as the one from the Marvel Legends line) were taller and bulkier than he actually is depicted as in the film, likely due to the influence of the classic comic design. They also tended to include Venom's long, dragon-like tongue from the comics, despite it being absent from his film design.
The troubles started soon after Spider-Man 2's release. Just after the film's debut, Sony immediately initiated production of a third installment, with Sam and Ivan Raimi spending two months crafting a treatment that would see Peter Parker growing as a character (and coming to realize that even criminals have humanity), the Green Goblin storyline being closed off, and Spider-Man facing off against the Sandman (and later, the Vulture, who was intended to be played by Ben Kingsley, with the latter being in negotiations for the role). Producer Avi Arad ordered Raimi to include fan-favorite character Venom in the film, despite his objections.
Rumors after the film's release (and mention in the retrospective by Midnight's Edge) suggest that Raimi hired Topher Grace to play Eddie Brock out of spite towards Arad, while the latter reportedly wanted Venom in the film in order to setup a spinoff (he would get his wish, in a roundabout way, more than a decade later with the release of the standalone Venom (2018), which is set in a different continuity). In addition, Arad and the producers to shoehorn in the Gwen Stacy character, and there was so much material on the drawing board that scriptwriter Alvin Sargent planned out scripts for an additional film after 3 in order to resolve all the subplots. Years later, Raimi would say in interviews that it was his fault for not keeping the various subplots trimmed down and in focus, and that he didn't believe in all the characters.
Kirsten Dunst only came back to the franchise on the condition that she would not be treated as a Damsel in Distress again, much like her involvement in the third act of both prior films, and after being told that Gwen would be taken hostage by Eddie/Venom during the climax (Mary Jane's role would be to convince Harry to help Peter during the final battle). The producers reportedly promised her this wouldn't be the case, but changed their minds afterward. They had to mollify Dunst (who was reportedly upset at the change) by making MJ into more of an Action Survivor, via giving her more to do (throwing a cinder block at Venom's head, for example) and swinging on hanging webs on her own, yet a number of screaming sounds she makes were overdubbed onto the scene after filming was completed. In the audio commentary for the film's DVD release, Raimi says that he had to create a setpiece to put the character in danger in order to get the project completed on-time, and that he was not only angry at himself for having to renege on his promises to Dunst, but that telling her about the changes was one of the hardest things he ever had to do as a director.
Bryce Dallas Howard (who played Gwen) learned that she was pregnant while filming the stunt scenes (which she decided to perform herself) during production... just before she was injured on-set when a desk hit her as she was shooting a scene where she falls out of the window of a building. Thankfully, neither she nor her baby were injured. Conversely, Thomas Haden Church (Flint Marko/Sandman) broke three knuckles when he punched a real brick during filming of the fight scene with Spider-Man in the New York subway system.
The film was intended to be muchDarker and Edgier, but numerous sequences and subplots were removed from the final product. Chief among them were scenes showing Peter being tempted by the Black Suit (and Foreshadowing that it was sentient by having it breathe as Peter looked on at it), along with a scene where he looks into a mirror and sees a nightmarish vision of himself as a monster. Another excised subplot had to do with Flint's daughter, who he would visit in a park in the shape of a sandcastle. Flint would learn during the finale that his daughter's illness is terminal and she begs him to spare Spider-Man, as she wants to die knowing that her father is a good man. Multiple participants in the production confirmed that the script was tweaked numerous times throughout filming.
Production was so strained that at one point, Raimi was helming multiple units himself, while cinematographer Bill Pope had trouble lighting scenes at night correctly because of the number of characters wearing black costumes or armor. Not helping matters was an incomplete trailer that leaked midway through production from promotional company Ant Farm, and showed off Venom for the first time after Sony had taken pains to keep the character's identity a secret.
Danny Elfman originally had no intent on returning to the franchise due to difficulties working with Raimi during production of the previous film. Christopher Young (who contributed themes for 2) was brought in to create the entire soundtrack, but this was changed after Young reportedly wrote a love theme that the producers didn't like, forcing the latter to bring Elfman back into the fold to aid with development of the score. This, in addition to musicians John Debney and Deborah Lurie being brought in to reportedly rewrite Young's love theme, led to a schizophrenic tone in the film's music.
While the final product was a box-office smash (grossing more than $890 million against a $250 million budget), it received a polarizing reception from fans who complained that it was overstuffed and poorly paced. Despite this, it was not the Franchise Killer it retroactively came to be seen as — there were still plans to produce a Spider-Man 4.
Even an alternate cut of the film ran into problems. The Editor's Cut (reportedly created by Bob Murawski to commemorate the 10th anniversary of the film in 2017) was done primarily to restore Young's original score, as well as adding additional scenes (including one that shows the Black Suit breathing as Peter looks at it in his apartment, as well as the "sandcastle" scene with Sandman and his daughter at the park), but it ran into its own issues when it was released unannounced, first by someone at Sony unintentionally leaking it on Amazon (where it could be streamed) then as an unlisted extra on the U.S. Limited Edition boxset.
The Vulture, who would've been played by Ben Kingsley, was originally going to be one of the main antagonists in the film and would play the Final Boss role that Venom ended up playing. He was ultimately scrapped since his role had no meaningful or personal connection to the hero at all, he was merely Flint Marko's cellmate who hated Spider-Man for putting him in jail to begin with.
An entire character was scrapped from the final cut. Adrian Lester would've portrayed a doctor whom Marko strong-arms into helping find a cure for his daughter, ended up on the cutting room floor, even though he had evidently filmed several scenes.
Spider-Man's symbiote suit was originally going to look identical to the one in the comics, being made of black latex. However, Sam Raimi thought it looked too much like a gimp suit and opted to go with a black and silver version of Spider-Man's original costume.
In the first trailers revealing his presence in the movie, Venom looked a lot more similar to his classic comic book portrayal, but was later changed to match his appearance in the film.
Neither Venom nor Gwen Stacy were present in the original planning packet, with a random woman serving the role Gwen later took.
Also, Gwen was originally going to be kidnapped for the final battle, not Mary Jane; Mary Jane would have talked sense into Harry instead of Harry's butler. A line Mary Jane said for this scene was actually used in the trailer: "We've all done terrible things to each other, but we have to learn to forgive each other or else everything we ever were will have meant nothing."
A scene with Eddie Brock coming to the Stacy's front porch and begging Gwen to take him back was actually filmed but not included in the final version, mainly since it connects with Gwen being the kidnap victim in the end, which was also cut.
The scene where Marko meets Eddie was quite different from the "90's Batman" villain team-up that was shown. After seeing Flint pretending to be sand in a park's playground for his little girl to play on, Eddie comes up and talks to him, and convinces him that his girl may be cured yet, and he will help him get the cash if Flint helps him take on Spider-Man. Images of this park scene being filmed actually exist. This, followed by him learning from his daughter that she is irrevocably sick and just wants to die with her dad a good man, makes his HeelFace Turn at the end, and Peter forgiving him, much more credible and poignant. These scenes most likely were considered, at least somewhere along the line - they were, after all, used in the Peter David novelisation in lieu of what the movie actually gave us. Though the novelisation presents Peter and Flint making amends partway through the battle, while the film shows it after Venom is defeated, and it's really up to the audience to decide which is better (since stopping a big climactic action sequence so that characters can clear things up is pretty hard to pull off in a film). Both exist in some form, at least.
It is also rumored that John Jameson was originally to have an appearance, unknowingly bringing the symbiote back from his astronaut mission like he has in two otheradaptations.
It is also rumored that J. Jonah Jameson hired Eddie Brock to spy on Peter, after MJ left his son at the altar.
Writer Revolt: Sam Raimi is not a fan of Venom, and has gone on record as saying that he dislikes the character's "lack of humanity." This is the reason for the movie's unflattering portrayal of the character.