Die Hard is based on the novel Nothing Lasts Forever by Roderick Thorp and compared to the movie, its pretty downbeat. The violence is genuinely unpleasant, there is no talk about Roy Rogers and at no point does anyone say, Yippie Ki-Yay, motherf**ker! The bad guys are a humourless bunch motivated by some political cause or other, they dont listen to Beethoven and are not defeated in a single night. Those changes were made by director John McTiernan, who in his DVD commentary claims he wanted to make a fun action movie (the word he actually uses is joyful). So together with screenwriter Steven E de Souza, he turned the hero into a wiseass, made the lead villain a charismatic scumbag you love to hate and gave him the purest motivation of all: avarice. No boring politics, no corporation-bashing, no lectures, just a movie about a common thief sorry, an exceptional thief and his greed. Its what Christmas is all about.