After returning to the laser hallway they find the bodies have vanished. This is a direct reference to the games, in which the bodies will vanish if you leave and reenter an area. Kaplan's lines draw attention to this.
Michelle Rodriguez had informed her agent that if anyone ever wrote a script about Resident Evil that she wanted to be a part of it. Her agent duly put her in contact with Paul W.S. Anderson when his screenplay was bought.
The main actors were told to prepare for the film by getting copies of the games and playing them through. Some of them didn't know if they could complete them in time so they had to get video copies of other people beating the games and then watch it.
The White Queen was slated to appear in the film but was excised from the screenplay. She was supposed to be the main Artificial Intelligence in the Umbrella headquarters monitoring the Hive. After the incident in the beginning, the White Queen would jam the systems of the Red Queen providing an explanation as to why the soldiers entered easily, since the defenses of the Red Queen were dysfunctional.
There is a shot of Alice's eye close up near the end of the film. This is a direct reference to the first game in the series; Resident Evil (1996). The close-up eye shot is the logo/title screen of the game.
According to Milla Jovovich on the DVD commentary, it was a crew member's birthday on the last day of filming. Bottles of champagnes were brought on the set. Paul W.S. Anderson was worried that the cast and crew would drink too much, but they said they'll just have a glass and no more. Sure enough, the whole cast and crew got drunk whilst waiting for filming the final scene in the film.
Connections to Alice's Adventures in Wonderland: - Main character's name is Alice. - Computer is named 'Red Queen'. - 'The Red Queen' needs to kill someone who is infected, so she tries to get someone else to chop off their head. (Off with her head!) - Alice in Wonderland paperweight. - A white rabbit was use to test the T-virus. - To enter the hive they go through a mirrored door (through the looking glass). - The Red Queen also succeeds in cutting off "her" head - the medic in the laser hallway. - Kaplan worries about time, as the White Rabbit does. (Mentioned in commentary) - Matt is sitting on the ledge when Rain and JD hear the first zombie. This is mentioned in the commentary as a reference to the Caterpillar.
Paul W.S. Anderson wanted to change the usual disclaimer at the end of the film to read that it didn't contain any resemblance to persons living or undead but he wasn't allowed to for fear of legal action.
To prepare for their roles, the actors playing commandos and Milla Jovovich and Eric Mabius had a week of commando training (climbing, martial arts, weapons handling, etc.) with former Navy SEAL Jaymes Butler.
In December 2001, Sony gave fans a chance to design the film's poster with the prize being an undisclosed amount of cash, a free screening of the film and the chosen design being used on all the advertising material. Nick des Barres, a 23 year old aspiring actor and ex-video game magazine designer, won the competition.
When the Red Queen is watching Dr. Green yelling at the camera when the room is filling with water ("There's no fire!"), her face gets magnified in a yellow box with data under it, one of which lists her name not as Dr. Green but as Dr. Anna Bolt, which is the name of the actor who plays Dr. Green.
Its successful opening weekend sparked a frenzy among US studios, eager to capitalize on the interest in video games. Titles like Ultimate Doom (1993), Silent Hill (1999) and Max Payne (2001) were all snapped up.
In the movie, Alice's fake husband is named Spencer. This is a reference to the first game which took place in a mansion named the Spencer Estate. Also, one of the three founders of Umbrella Corporation in the game series is named Ozwell Spencer.
Near the end, when the underground tram pulls back to the Mansion station, the serial number on the front of the lead car reads "ALEXIA" followed by a string of digits. Alexia Ashford is the final antagonist of Resident Evil Code: Veronica. Also, Undeground Trams are a recurring mode of transportation in the Resident Evil games.
Clashes with the studio - particularly after his experience with Event Horizon (1997) - prompted Anderson to seek financing in Europe. This came from Germany's Constantin Film and the UK's New Legacy. Sony Screen Gems picked the movie up for distribution halfway through preproduction.
The banner on the bus in the end of the movie shows several toys on the right, among them a teddy bear. The text on the left reads: "At Umbrella Medical, we try to make teddy a little softer". Along the bottom, it reads: "Umbrella Medical - Sheltering Your Family".
Two full-scale Lickers (the 'Creature') were made. One was more detailed than the other and was capable of many movements (the jaw and lips could part open, the tongue could extend). The other was for wider shots where the whole body was seen.
The wedding picture of Alice and Spencer looks similar to the pictures from Resident Evil (1996) and Resident Evil 2 (1998) (with the subjects up close and spliced onto the background image, and always in black and white).
Opened with a $17.7 million dollar opening weekend. The second weekend's haul was down to $6.7 million and at the third weekend, it had nosedived down to $2.9 million. It fell out of the Top Ten after only 2 weeks, dropping from appearing at over 2500 screens down to just 67. Still, with a production budget of $33 million and a domestic gross of $40 million ($102 million worldwide), it is seen as a success.
Reference to Resident Evil Code: Veronica X (2000): Matt runs into his sister that is now a zombie and has to watch her "die". This is similar to Steve Burnside having to watch his zombie father die, but by his own hands.
The Red Queen's presence is stated many times in the film mostly by dialogue or via the screen displays when the computer seals off the Hive in the beginning and when it identifies the soldiers who infiltrate the facility. The holographic representation however is visible in only one scene. For the rest of the scenes featuring the dialogue of the Artificial Intelligence, the voice comes from audio speakers without any visual appearance.
In the script the soldiers arrived at the mansion by helicopter . They would even have communication via radio with the chopper pilot before they entered the Hive. Although this subplot was dropped there are still hints of the chopper's presence. In the scene where they are debating if they should take Matt along and Rain makes a rude retort to Matt , you can still hear the chopper flying if you pay attention.
Another Alice Through the Looking Glass reference is the fact that when Alice wakes up in the bathroom she is lying next to a chess formed floor. This implies that Alice is right before the beginning of her journey in the Looking Glass land (like a pawn at the beginning of a chess game). In the final scenes Alice and Matt are on the hallway of the mansion's entrance , which has the same chess formed floor with black and white squares . This means that their journey has ended.