While the highway scenes are supposed to take place on the Saw Mill Parkway in Westchester County, NY, they were actually filmed on the Merritt Parkway in Fairfield County, Connecticut, and on the Taconic Parkway in Putnam County, NY.
When the bomb goes off in the Bonwit Teller department store, there is an "Atlantic Courier" truck parked in front of the store that gets flipped over. In Die Hard, Hans Gruber and the other terrorists arrive at Nakatomi Plaza in a "Pacific Courier" truck.
Director John McTiernan considered either editing out the beginning bombing of the department store, or moving the release date back as they felt that the American public might still be sensitive to bombing due to closeness of dates of the Oklahoma City bombing of the Alfred P. Murrah Federal Building.
The sandwich board that Bruce Willis wore while filming in Harlem was originally covered in special effects markings rather than text to ensure no one was offended by the racist message. The "I Hate Niggers" was added with CGI in post-production. Some television broadcasts use an alternate version where the sign reads "I hate everybody", which is sometimes erroneously said to be the original version of the sign used for filming, but this too was added with CGI in post-production.
First version of the screenplay was based on a spec script by James Haggin called "Troubleshooter" which involved terrorists seizing control of a Caribbean cruise ship. The idea was abandoned after Steven Seagal's Under Siege went into production. In 1992 John Milius was hired to write another version of the story. In 1993 Doug Richardson and John Fasano simultaneously worked on two separate Die Hard 3 scripts which were both rejected by Bruce Willis. This time the plot was concerned with terrorists taking control of the L.A. subway system.
Director John McTiernan acknowledged the errors concerning the gold in the dump trucks and its respective weight. McTiernan and Samuel L. Jackson were permitted to lift a genuine bar of gold to get a feel of how heavy gold really was.
During its Pay Per View run in 1996, a bonus featurette followed the presentation of the movie which included footage of some scenes with additional dialogue such as the scene in the Federal Reserve Bank where Felix Little asks "You're in the flower business, Mr. Vanderflug?" and added is Simon replying "It's Vanderfluge, it rhymes with tulip." explaining why Felix pronounces the name correctly from that point on. This featurette is not included in the Special Edition DVD.
When Simon, posing as the city engineer, meets Ricky Walsh, you can see a blurry but visible red sign on the building in the background. This is the Home Insurance Company building and that company purchased the red cover so that it would be seen in the movie as they felt that the original bronze signage would not be visible.
In the DVD commentary, Jonathan Hensleigh says that the first hour of the film is his original "Simon Says" script word for word. He only changed the characters from the script, so that it would actually feel a part of the "Die Hard" series.
Jonathan Hensleigh was actually detained by the FBI after completing the script for the film because he knew extensive information about the Federal Gold Reserve in Downtown Manhattan. Hensleigh stated that he got all the information from an article written in the New York Times.
The bridge from which McClane and Zeus jump to the container ship in the harbor is the Cooper River Bridge that connects Charleston and Mount Pleasant, South Carolina. A new bridge opened in July 2005, and the two pre-existing bridges that have long been a symbol of Charleston will be removed. Much of the film was shot in the Charleston area, including the subway station which was built on a stage in Mount Pleasant. The Cooper River Bridge scenes were set on an unnamed bridge near Bridgeport, CT, on Long Island Sound.
As in the previous Die Hard, the German spoken in this movie is mostly grammatically incorrect. A few lines are so wrong that they have to be considered gibberish (most notably the exchange of the fake cops, who are given the briefcase bomb by Zeus (Samuel L. Jackson)). In the German release, however, all of the lines that were German in the original movie are grammatically correct, fitting the context and some of the terrorists even have an East German accent.
The producers planned to blow up the Hutchinson River Parkway tollbooth structure for a scene in the movie. The tolls were to be eliminated anyway, and then-Governor Mario Cuomo volunteered to push the switch. But opposition from local residents in close proximity and from other officials killed the idea.
Despite not being set at Christmas, it still references the previous films (which were set at Christmas) with sarcastic comments regarding Santa Claus. The shoplifting kids also states that "It is Christmas you could steal city hall." Another reference takes places when McClane is in the aquaduct, mentioning "We got a report of some guy coming through here with eight reindeer", McClane then shoots the terrorist and continues, "They said he was a jolly old fat guy, with a snowy white beard, and a cute little red-and-white- suit. I'm surprised you guys didn't see him."
WILHELM SCREAM: As they are driving through the park Zeus asks McClane if he is aiming for the people, to which McClane replies, "No... maybe that mime." An abbreviated Wilhelm Scream can be heard immediately following the "No."
On the DVD commentary, screenwriter Jonathan Hensleigh says the idea for the film's plot came to him when he imagined what would happen if one of his childhood friends, who was injured after Hensleigh threw a rock at him, decided to seek revenge on him as an adult.
The studio told screenwriter Jonathan Hensleigh to remove the scenes with McClane walking around Harlem wearing a sign that says, "I hate niggers." They allowed him to keep the scene when he threatened to take the script to another studio.
In the wake of the Oklahoma bombing, 20th Century Fox took out trade press ads defending their decision to continue with the imminent release of a film about a terrorist planting bombs in public places.
In the scene where Zeus (Samuel L. Jackson) is trying to get out of going with McClane (Bruce Willis) on the trip across the city, he [Zeus] gets up, exclaiming, "I'm not jumping through hoops for some psycho! That's a white man with white problems, you deal with him! Let me know when he crosses 110th street." The line "Across 110th Street" is a reference to the song of the same name that was played in the film Jackie Brown, which also starred Samuel L. Jackson.
The main theme for this movie is "When Johnny comes Marching Home," an Irish song made famous in America by Patrick Sarsfield Gilmore aka Louis Lambert in 1863. This is the first Die Hard Movie where audiences got to see John McClane battling a terrorist in his home town (New York). The previous two movies had him battling terrorists in L.A. and Washington D.C., both of which were simply places he was visiting on holiday at the time.
The line spoken by McClane "Smoking cigarettes and watching Captain Kangaroo" is taken from a song called "Flowers on the Wall" by The Statler Brothers, which also appears in Pulp Fiction, also featuring Bruce Willis and Samuel L. Jackson. Willis is singing along to this song on the radio when he runs into Marcellus Wallace.
There is a mathematical formula that can be applied to the St. Ives problem, called the Geometric Progression Formula, which is a(r^n - 1)/(r-1), "a" being the first term, "r" being the common ratio, and "n" being the number of terms of the geometric series. The 7 wives would be "a". The following 7s would be the common ratio. "N" would be 4 (i.e. kittens, cats, sacks, and wives). This translates to 7(7^4 - 1)/(7-1) = 7(2401-1)/6 = 7(2400)/6 = 16800/6 = 2800. This is all assuming the narrator going to St. Ives. and the man with seven wives are excluded.
After their run across New York, Zeus (Samuel L. Jackson) accuses McClain (Bruce Willis) of being out of shape for a cop. McClain replies that he has been on suspension so he has been sitting around "smoking cigarettes and watching Captain Kangaroo." In the film Pulp Fiction, which stars both Willis and Jackson, the song "Flowers On the Wall" where this quote is from is playing on the radio in Willis' characters car just before he runs it into Marsellus Wallace outside his apartment.
On the DVD commentary Director John McTiernan mentions that Dick Cheney appears in a scene. He actually says "here he is", but Dick Cheney is not in the film - the person shown in the scene has a slight physical resemblance but is not Dick Cheney. The director made an error.
The original casting of Simon's terrorist crew was with a mix of Soviet and Warsaw Pact baddies and not East Germans. Only one Polish character (Otto) was retained from initial casting and he became the butt of the East German's demeaning jokes.
When McClane boards the elevator at the Federal Reserve with Karl and the rest of Simon's men, during the casual conversation Karl is having with McClane, Karl refers to the elevator as the "lift". This would potentially betray Karl, who is trained in infiltration and disguised as a Federal Reserve guard, as being European and therefore a potential imposter since "lift" is the European term for elevator.
The trivia items below may give away important plot points.
The 2003 R1 DVD version includes the original ending showing McClane and Simon playing a game of 'chicken' with a rocket launcher. In this original version, Simon Gruber and his crew get away with the gold and months later, McClane tracks Simon down in Eastern Europe (where in Europe is debated: McClane mentions Germany, but people in the background are heard speaking Hungarian) The number on the bottom of the aspirin bottle (at the phone booth) leads McClane to Gruber. The gold was turned into small miniatures of the Empire State building and smuggled out of the country. McClane is thrown off the force, with the police thinking that he may actually be involved in the heist. The "game" that McClane and Simon play is about riddles that McClane tells Simon, and he is supposed to figure out the answer, or McClane will force him to fire a rocket launcher with its directional arrows removed, so neither will know which direction it will fire in until it is actually fired. The scene climaxes with McClane forcing Simon at gunpoint to fire the rocket launcher, which kills Simon, and McClane is revealed to be wearing a flak-jacket, which would have saved his life if the rocket launcher had fired at him instead of Simon. The studio objected to the ending, saying that it made McClane too cruel and heartless, whereas screenwriter Jonathan Hensleigh stated that that was exactly the point: to show that McClane had been pushed over the edge by the events of that day, and then subsequently losing everything as a result of Simon.
There are two solutions to the water jug riddle in the park, at the elephant fountain. To place exactly 4 gallons of water on the scales when you only have two jugs which hold 3 and 5 gallons respectively, you must do either of the following. 1. Fill the 5 gallon jug and decant the water into the 3 gallon jug. This leaves two gallons in the big jug. 2. Empty the 3 gallon jug and pour in the two gallons from the 5 gallon jug, leaving space for one gallon in the small jug. 3. Refill the 5 gallon jug and pour water from it into the 3 gallon jug until the small jug's full. 4. That leaves exactly four gallons in the big jug; put it on the scale and the bomb is disarmed. The second method is: 1. Fill the 3 gallon jug and pour the water into the 5 gallon jug. 2. Refill the 3 gallon jug, and pour into the 5 gallon jug until the big jug is full, leaving one gallon in the small jug. 3. Empty the big jug, and transfer the one gallon from the small jug to the big jug. 4. Refill the small jug and pour all three gallons into the 5 gallon jug, resulting in four gallons in the big jug. Place the big jug on the scale and the bomb is disarmed.
McClane only has two bullets at his disposal to kill Simon in the finale of the film. He also only had two bullets in the first Die Hard to kill Simon's brother, Hans, and his last remaining associate.
Each of the Gruber brothers, Simon and Hans, recruit a Karl on his team. Karl in Die Hard is the terrorist shot by Sgt. Powell at the end. In this film Karl is stationed at the Federal Reserve bank and is killed by McClane in the elevator sequence.