1. The action flick is based on the book Nothing Lasts Forever by Roderick Thorp. The villain Anton Gruber was changed to Hans Gruber, Joe Leland was changed to John McClane, and McClane is visiting his estranged wife instead of his daughter and grandchildren. The novel was a sequel to The Detective, which also had a movie adaptation. The star of that movie was Frank Sinatra and he got first dibs on starring in Die Hard. He decided to pass.
2. Willis was not the studio’s fourth, fifth, or really top ten choice for their star. He was seen as a comedic actor and they felt that a real action star was needed. Nevertheless, Willis got the part and a then astonishing $5 million payday.
3. Willis was filming Moonlighting while shooting this movie, leading director John McTiernan and screenwriter Steven E. de Souza giving more screen time to formerly minor characters to make up for their exhausted star.
4. Die Hard was the late Alan Rickman’s first film role. McTiernan and producer Joel Silver saw him perform as Valmont in a stage production of Dangerous Liaisons. That performance led to Rickman becoming the terrorist antagonist.
5. Nakatomi Plaza, the backdrop for the entire film, was actually 20th Century Fox’s headquarters. The studio charged itself rent for use of the partially completed building. McTiernan also had to apologize for those people working on other floors of the building, as the gunshots and real explosions set off inside were a bit counterproductive to office work.
6. So about those gunshots being loud — Willis suffered permanent hearing loss when he filmed the scene where McClane kills a terrorist by shooting him through the bottom of a table. McTiernan wanted it to be realistic and used extra loud blanks. The gun was so close to Willis’ ear that it caused two-thirds partial hearing loss.
7. Terry Gilliam so enjoyed Willis’ improvisation during the barefoot on glass scene that it led him to cast the actor in 12 Monkeys.
8. On Hans Gruber’s death fall:
9. The infamous “Yippee-ki-yay, motherfucker” was another improvisation by Willis that he threw in to get a laugh from the crew. He never thought it would get to stay in the final cut. The line would go on appear in all of the Die Hard sequels and was voted #96 of “The 100 Greatest Movie Lines” by Premiere in 2007.
OR it was a planned line with McTiernan.
10. Actors rumored or confirmed to have been up for the role of John McClane:
I don’t know why the actor list is like that, but I approve.