Trivia: While on the helicarrier, Tony Stark is wearing a Black Sabbath T-shirt, the band who released the song "Iron Man".
Trivia: Even though Frank the pug doesn't appear, there are a couple of references to him. The first one is a big picture of him over J's bed and when J gets pulled over by the cops, there is a billboard advertising for "The Amazing Talking Pug." (00:22:35 - 00:40:25)
Trivia: A relief carving of Sulley (from the following Pixar film, Monsters University) is visible in the Witch's cottage.
Trivia: The missiles fired by the alien ships are the same shape as the pegs in the board game.
Trivia: Peter Parker falls through a roof and lands in a wrestling ring, where he gets the idea of using a mask, a homage to the original comic and the first Sam Raimi film, where Peter tests his spider powers by entering a wrestling match.
Trivia: Comedic actor Thomas Lennon has a small role as the doctor Bruce sees for a check-up before he visits Gordon. Lennon previously played a similar role in director Christopher Nolan's "Memento" (as the doctor the character Sammy Jenkis visits). Lennon stated that Nolan specifically wanted him for the role of the doctor in this film, and has speculated that perhaps Nolan considers them to be the same character.
Trivia: Katniss Everdeen and Peeta Mellark are the only Hunger Game tributes ever referred to by their first and last names. The other tributes are just identified by their first names, even when they're being introduced by Caesar Flickerman during the televised interviews or their scores are being announced on television.
Trivia: Kate Beckinsale's stunt double Alicia Vela-Bailey makes a cameo during the opening sequence as a vampire escaping the purge. (00:03:40)
Trivia: Originally Clair and Chris Redfield were to appear in the film after having been featured in previous movies. But script-changes lead to them being written out, and their fates were left ambiguous. Clair will be re-appearing in the sixth film, however.
Trivia: Joseph Gordon-Levitt injured his arm whilst filming after colliding with a taxi window with his bike and required 31 stitches. A behind the scenes clip of this can be seen partway into the end credits.
Trivia: Kristen Stewart performed many of her own stunts in the movie.
Trivia: Dredd's face is never shown during the film. This is consistent with the comic strips in which Dredd is almost never shown without his helmet and, on the rare occasions when he is, his face is obscured in some other way. Fans were critical of the 1995 Judge Dredd film for the fact that Dredd spent much of the time with his helmet off and his face exposed.
Trivia: Booker is a nod to "Good Guys Wear Black" in which Chuck Norris portrayed a character named John T. Booker. In both films Norris plays a retired military operative in a rescue mission to help his old comrades.
Trivia: Emily Blunt signed on to the film after reading the first half of the script. She hadn't even gotten to the scene where her character was introduced.
Trivia: This is Colin Farrell's second role in a movie adopted from a story by Philip K Dick; his first performance was in 2002's Minority Report.