One of six narrators in “Mudbound,” future bride Laura, introduces her intended this way: “My world was small, and he was my rescuer from a life in the margins.”

Efforts to widen people’s worlds, and transcend limits imposed by blind or hostile forces, are a major preoccupation for 2018’s Academy-nominated screenwriters. By tackling themes of racism, classism and sexism in unexpected, unconventional ways, they derive not just immediacy and provocation, but heightened dramatic interest as well.

The multiple voice-overs of “Mudbound,” for instance, allow Virgil Williams and Dee Rees to present what Williams calls “a spherical look at humanity,” placing the various Mississippi Delta characters on a spectrum “from pure to impure” while evoking the shared inheritance that dissociates everyone, black or white, from power. “It doesn’t matter what color, what creed, what gender you are,” Williams says. “We’re all trapped here on earth together, bound by the mud of ignorance, hate and fear. And the only way to get clean is together, and with love.”

Getting clean together is critical to “The Shape of Water,” which assembles a virtual Justice League of the powerless — an aging gay bachelor and two cleaning ladies — to confound sinister bureaucrats. Setting their quest in JFK’s can-do Camelot era, says Guillermo del Toro’s writing partner Vanessa Taylor, reveals a hollowness in the American Dream. “For people at the margins, that dream was never real in the first place. … For those with less access to the nexus of power, those dream versions of America can seem at worst a cruel joke, at best a distant and unlikely goal.”

The movie proposes fearlessness as the answer in the person of its silent heroine: “In the face of intimidation, she is not afraid, only galvanized to oppose injustice and fight for love.”

The underrepresented help two nominees explode genre conventions. While most superheroes go it alone or as part of an avenging Delta Force, “Logan” gets support from a disabled nonagenarian, African-American sharecroppers and Hispanic immigrants. Director James Mangold says he and partners Scott Frank and Michael Green imagined “the unwanted, the outcast, the refugee” journeying through “this dissipated heartland, in which there were a lot of broken dreams which they will visit along the way while trying to solve their own problem.”

In the X-Men universe, Mangold says, “mutants are a talented, but marginalized group, always fighting not just villains, but for their own respect and legitimacy.” As a fresh way of closing out one mutant’s story, the writers explored what it would be like “to be with superheroes on the short end of the stick,” facing diminishing returns of body and spirit. Even a superhuman, evidently, can live tenuously on the margins.

Meanwhile, Kumail Nanjiani says he and his wife, Emily V. Gordon, crafted “The Big Sick” as a piquant romantic comedy, “but we also wanted to encapsulate the experience of being from a demonized group in America.” With their main character a Muslim stand-up comic, they drew from real-life, verbatim racist heckles and Nanjiani’s hilarious comebacks.

The real joke, he says, is “how unsurprising it is to him to be discriminated against.” During a heated fraternal quarrel, a family’s stares cause the men to deflect, another funny moment based in truth: “We know that as a brown man, you can’t really raise your voice in public. … You’re always hyper-aware of how people are seeing you.”

One film delving deep into the psychology of the sidelined is the brillliantly subversive “Get Out.” Jordan Peele’s protagonist Chris is cruelly hypnotized into “The Sunken Place,” a sort of Dead Zone separating mind and body, that Peele realized “is a metaphor for the system that silences voices on the margins, whether that is black voices, or voices of women, or gay voices or any other minority. There is this feeling that one has, when one is rendered voiceless. I think the film has resonated pretty strongly because the idea makes a lot of sense, and represents that feeling of not having a voice, not having agency.”

Violating prevailing norms, other writers suggest, can contribute to marginalization. Through attention-getting public scenes, pretending not to live on “the wrong side of the tracks” and dubbing herself “Lady Bird,” Greta Gerwig’s big-screen protagonist invites parental bemusement and peer scorn, making it tougher to pull her life together than someone of her intelligence and self-awareness deserves.

Mildred Hayes is an even bigger scandal-creator with her “Three Billboards Outside Ebbing, Missouri.” In the film, Martin McDonagh carefully charts how escalating rage at inattention to her daughter’s killer increases isolation from family and community alike.

Even movies preoccupied with privilege can tap into outsider concerns. As scripted by Aaron Sorkin in “Molly’s Game,” real-life child of prosperity Molly Bloom is beset by enough class prejudice and sexism to set Mildred Hayes nodding in grim recognition. Lady Bird McPherson would identify with Elio Perlman’s anguish at first-love-lost in James Ivory’s script for “Call Me by Your Name.”

And in chronicling career struggles in “The Disaster Artist,” Scott Neustadter and Michael H. Weber shrewdly pass over Tommy Wiseau’s seemingly unlimited bankroll, instead engaging our sympathy through the would-be filmmaker’s alienating strangeness.

Encouraged by progress made in what Taylor calls stories told “through the lens of outsiders,” the writers know much remains to be done. Taylor urges caution against “enforcing stereotypes and harming the very interests we hope to promote.”

Nanjiani hopes filmmakers will tell it true; to idealize underrepresented characters, he says, “would be just as unfair as not telling those stories at all.”

Mangold simply calls for “more movies,” confident that “the more the marketplace is crowded with media, the more financiers are willing to take a chance on something other than the standard way of casting and depicting your principal characters.”

Notably, two of the year’s nominees, “The Shape of Water” and “Mudbound,” culminate in a romantic apotheosis for characters whose voices have literally been removed. Though their rapture comes at a painful price, the emotional lift of their triumphs may presage a next generation of movies in which, as Virgil Williams puts it, “we learn to stand in our truth, and allow other people to stand in theirs.”