Ah, those halcyon days of non-digital film production. Die Hard came out in 1988, before George Lucas ushered in the digital revolution with The Phantom Menace. That means that all those effects you see—the explosions, fights, and fires—they're all real. Yep, Die Hard was shot in good old-fashioned Panavision.
And because it's pre-digital, much of Die Hard was also shot right on location—at the brand-spanking-new Fox Plaza in Century City, Los Angeles. Much as the movie would suggest, they used the building's upper floors, and it was a bit of a legal nightmare to get Fox to agree to all the shenanigans they intended to pull. Yeah, we'd say that's a bit different from just paying a pasty techie to create the roof explosion on his laptop.
To create a believable background of the skyscraper's sweeping view of L.A., the production designers created a 380-foot wraparound mural with "animated lights and various lighting techniques to create day and night effects" to surround the set. So while the movie was shot on location, those production designers had more than a few tricks up their sleeves, including a green screen and scale models. You didn't think they'd really let Alan Rickman fall from the top of a 35-floor building did you?
For more on how the movie's on-location production affects Die Hard's story, check out our "Setting" section.
Fun fact: After production on Die Hard wrapped, former President Ronald Reagan moved into Fox Plaza's 34th floor suite. Apparently, when his chief of staff first scoped out the space, there were still bullets littering the floor.