Michael Fassbender as Magneto in "X-Men: First Class."

Lately, there have been some rather terrible franchise reboots occupying box offices, from Disney’s “Tron: Legacy,” to “Clash of the Titans.” But those failures pale in comparison to the wreck that was 2009’s “X-Men Origins: Wolverine,” which was universally panned by critics and seemingly left its franchise for dead. Surprisingly, though, Matthew Vaughn’s “X-Men: First Class” succeeds in being everything that “Origins” was not: exciting, deep, and coherent. “First Class” delves into the relationships and back-stories of some of the most notable characters in the X-Men universe—namely Charles Xavier/Professor X (James McAvoy) and Erik Lehnsherr/Magneto (Michael Fassbender)—and  succeeds in complicating an aging franchise without sacrificing the characteristic sense of action and adventure of the X-Men movies.

The standout features of “First Class” are the dark and oft-disturbing origin stories of the mutants that later come to be known as the X-Men, and the fraught relationship between Xavier and Lehnsherr. Instead of gamma rays and spider bites—the catalysts of lesser films of similar bent—“First Class” gives its characters emotional, rather than supernatural, coloring. The cast includes a little girl who can only survive by stealing food because the world doesn’t accept her appearance, and a boy who watches as a man murders his mother in a concentration camp.

Thus, even though the film’s characters are not homo sapiens per se, there is something distinctly human about the pain they are forced to endure due to the world’s intolerance. And due to the characters’ unmistakable humanity, the conflict between the good-hearted Xavier and the jaded, embittered Lehnsherr is powerfully endowed with moral ambiguity. “First Class” is more than the standard struggle between good and evil found in most superhero movies. Instead, it is about two equally valid but radically different world views. Xavier—ever the optimist—refuses to turn his back on the humans, while Lehnsherr refuses to continue to allow humanity to oppress him and those like him. The uniqueness of “First Class” is that it gives the audience the chance to assess the morality of both viewpoints without passing judgment itself.

Another triumph for “First Class” is its fresh-faced cast. James McAvoy, Michael Fassbender, and Jennifer Lawrence (Raven/Mystique) give the 48-year-old franchise a new look and bring a youthful energy to the film that hasn’t been present in previous iterations. At one point in the movie, the mutants even throw a dorm party of sorts, complete with funky ’60s music and someone dangling upside-down from the ceiling. This departure from the norm will surely help the franchise expand its fanbase and keep the X-Men story relevant.

Not that the film is without the occasional misstep. As entertaining as “First Class” is, anybody completely unfamiliar with the X-Men franchise will likely be thoroughly mystified by it. Unfortunately, fluency with the story—the mission of Professor X, the conflict between Magneto’s Brotherhood of Mutants and the X-Men—is required to understand the significance of the characters’ back-stories. Without knowledge of the events that lie ahead, the background provided in the movie simply will not mean as much to the audience. And while the relationship between Charles Xavier and Erik Lehnsherr is thoroughly developed, their connections with other characters often leave a lot to be desired. Take, for example, the romance between Xavier and government operative Moira MacTaggert (Rose Byrne) that culminates in a kiss at film’s close, despite the lack of build-up and explanation as to how this attraction came to be in the first place. But the strengths of “First Class” far outweigh these scattered weaknesses.

Perhaps the reason that “First Class” was able to far outshine its predecessor is that it once again carries the classic X-Men mantra of tolerance. Ever since the first X-Men comic debuted in 1963 in the midst of heightened racial strife in the United States, its message of acceptance has continued to be relevant in an ever-divided society. For its part, “First Class” suggests that the key to surviving in a world where it is still difficult to be different is to foster a sense of belonging, much like Xavier attempts to do with the mutants by constantly reminding them that they are not alone in their struggle to be accepted into society. With this poignant message, a winning cast and a compelling plot, “X-Men: First Class” is a breath of fresh air in a franchise that has long needed some kind of mutation of its own.

—Staff writer Charlotte D. Smith can be reached at charlottesmith@college.harvard.edu.