When the screenplay for "Die Hard" first circulated among Hollywood agents and A-list actors, it was met with skepticism and dismissal. The character of John McClane, who would become an iconic action movie hero, seemed weak compared to the larger-than-life heroes dominating the genre at the time. James Caan and other top actors passed on the role, deeming the character insufficiently tough.

Bruce Willis, known for his role in the TV show "Moonlighting," initially turned down the part due to his commitment to the series. However, when his co-star Cybill Shepherd became pregnant, providing Willis with an unexpected hiatus, he reconsidered. Despite being an unlikely candidate for an action role, Willis eventually accepted the role of John McClane.

The director of "Die Hard," John McTiernan, had doubts about Willis's suitability for the role, particularly after negative reviews of his acting in the film "Blind Date." However, Willis impressed the filmmakers by transforming himself physically and mentally for the role. He quit drinking, started working out rigorously, and even went to Alcoholics Anonymous.

The filming of "Die Hard" presented numerous challenges for Willis. In the very first shot, he had to jump from a ledge onto an airbag while being engulfed in a fireball. The risks involved in such scenes were evident when Willis narrowly missed the airbag. Balancing the shooting schedule of "Die Hard" with his commitments to "Moonlighting" proved hectic for the actor.

During the shoot, tensions arose between Willis and the director, McTiernan. They clashed over blocking for an action sequence, which stemmed from Willis's concerns about his thinning hair. McTiernan assured him that their job was to make him look good.

As the filming progressed, Willis became more comfortable, and his humor and wisecracks from "Moonlighting" made their way into the character of John McClane. He also brought a sensitive side to the role, adding depth to the character's emotional moments.

Despite initial doubts about Willis's box office appeal, "Die Hard" proved to be a massive success. It became the highest-grossing action film of 1988 and solidified Willis's status as a major action star. The movie's quality and Willis's performance ultimately overshadowed any early skepticism or challenges faced during production.