We latched onto Die Hard's version of John McClane because he's a relatable hero, an everyman with a quick wit and real vulnerability. Up to that point, audiences knew Willis primarily as the sarcastic, flirty private eye on TV's Moonlighting, and from lead roles in a couple of Blake Edwards comedies. At that time, Willis as an action hero was as out of left field as if Paul Rudd had been cast as Jason Bourne—and it's even weirder when you consider that Die Hard came out in an era when Stallone, Schwarzenegger, and Van Damme were the template for the successful action star.

Die Hard works so brilliantly because even if we know that action-movie rules dictate that McClane is going to win, we can't get it out of our head that this guy really could die. The words chosen for the title aren't insignificant in this respect: Die Hard means something very different from, say, Die Impossible, and the latter is closer to the spirit of the standard-issue '80s action flick—and to what the Die Hard series has become.

Director John Moore was keen to include plenty of references to the original Die Hard in his latest chapter, A Good Day to Die Hard, out this week. While his visual quotation of Gruber falling to his death in one scene was amusing, there's another parallel scene that underlines just how Die Hard really has become Die Impossible.

In the original film, McClane manages to escape from attack on a rooftop by tying a fire hose around his waist and leaping off the side of the building. He then has to do some glass-shooting of his own, breaking a window to get back in. People fall easily through windows all the time in movies, so his need for extra firepower to get through was a refreshingly realistic touch.

In A Good Day to Die Hard, McClane goes through an exterior window in much the same fashion. Moore films the moment in the gratuitous, Zach Snyder-like slow motion that he favors in (too) many of the movie's key moments, and the slowed-down speed actually highlights the implausibility of the sequence. We now have an agonizingly long period of time to ponder how he smashes so easily not just through an exterior window but also the presumably even-more-sturdy frame of the window at the center of his impact point. Apparently John McClane is now part wrecking ball.

Most action movies require a healthy suspension of disbelief. That isn't a problem, so long as the film earns it. Could someone actually jump off a roof with a fire hose wrapped around their waist and survive the jolt at the bottom? That's probably a question for the Mythbusters, but as presented in the movie, I was willing to buy it. The gore of the glass-walking aftermath, and the affecting defeatism of Willis's performance earlier, help sell these later strains in plausibility.

But when the films become cartoonish in their approach to how injury and adversity affect McClane, he goes from man to superman. We mere mortals can no longer relate. Even the third entry, 1995's Die Hard With a Vengeance, which was the only sequel to even approach the heights of the original, is guilty. While McClane's bleary, hungover state does help bring him down to earth, shooting him out of a drainpipe atop a jet of water like something out of an old Looney Tunes short quite literally does the opposite. And that's without even mentioning the coincidence of his reluctant sidekick Zeus (Samuel L. Jackson) just happening to drive by that pipe at the exact moment McClane fires out of it.