The epic battle at the center of “Warcraft” isn’t the clash between humans and orcs. That’s just what takes up roughly two hours of screen time. The true conflict comes from filmmakers trying to tell a story with soul and struggling against the inherent ridiculousness of the commodity they’re working with. It shouldn’t take a mage to foresee that this pricey and preposterous adaptation of an online gaming phenomenon was preordained for artistic mediocrity.

With little concern for all those already perplexed at the mention of orcs and mages, “Warcraft” plunges headfirst into a fantasy realm teeming with mythical creatures, magical spells and exotically named characters and locations. It’s a take-it-or-leave-it approach likely to have most audience members opting for the latter, though devotees of the immersive role-playing source material may have an entirely different experience. If so, Universal will have to hope they storm the box office early and often. Otherwise the studio could be looking at one of the biggest duds of the summer.

That’s despite the noble effort of director Duncan Jones, who helmed the lower-budget sci-fi wonders “Moon” and “Source Code” and labors mightily here to craft a solid emotional foundation in his script with Charles Leavitt. The “Warcraft” games — which have radically declined in popularity from a high of 12 million regular users in 2010 to a recent low of close to 5 million (so low the company behind it no longer releases subscriber counts to the public) — were never meant to have the narrative depth of “The Lord of the Rings,” or even “Game of Thrones.” But the film cribs freely from both of those sources anyway, as well as “Star Wars,” “Dawn of the Planet of the Apes,” “Avatar” and numerous other recent blockbusters.

The orcs, a race of giant warrior beasts, flee their dying homeland of Draenor through a portal to the peaceful realm of Azeroth, where they wage a full-scale attack on unsuspecting humans for control of the land. Orc soldier Durotan (Toby Kebbell, like all orc players, working in performance capture) questions the brutal ways of his clansmen — led by warchief Blackhand (Clancy Brown) and power-hungry warlock Gul’dan (Daniel Wu) — and believes a compromise without bloodshed is possible. His counterpart on the human side is Anduin Lothar (Travis Fimmel of TV’s “Vikings”), a knight devoted to serving his benevolent king and queen (Dominic Cooper and Ruth Negga).

Durotan’s fierce mate Draka (Anna Galvin) delivers an adorable orc baby early on, and Lothar’s son Callan (Burkely Duffield) is determined to impress his father on the battlefield. Those family ties are duly exploited for maximum melodramatic impact, as the dual protagonists rage and question and mourn and soulfully ponder the complexity that exists on two sides of any conflict.

Ditto Garona (Paula Patton), a slave claiming to be half-orc, half-human, who makes her way through the portal and finds herself torn between the two sides. She quickly gets cozy with Lothar, but it’s hard to take Patton or the character seriously with her “Star Trek”-alien-esque green skin and the oversized fangs jutting out from her jaw, looking like a last minute find in the Halloween store bargain bin, and making her sound like she has a mouth full of magic beans.

And that goes to the root of the problems with “Warcraft”: it’s an unwaveringly earnest film that never owns up to exactly how campy every character, every conflict and every new realm truly is. Ben Foster has another central role as reclusive wizard Medivh, a “Guardian” of Azeroth who has been not so subtly dabbling in dark magic. He’s introduced sculpting a golem (surely you’ll recall the old chestnut about Chekhov’s golem), shirtless and wild-eyed, but it takes Lothar quite some time to piece together the warning signs. Medivh should be fun, but Foster’s deadpan turn is, like the movie around him, a drag.

With its meticulously detailed realms built out primarily on soundstages and enhanced via CGI during extensive post-production, “Warcraft” aims for fresh and eye-popping and yet ends up shopworn and rather tacky. It fits into a long line of visually audacious Hollywood gambles: In success you wind up with a sleeper that few see coming, like “300” (or, if you strike the bull’s-eye, a phenomenon like “Avatar”), but the ones that miss — “The Spirit,” “Sky Captain and the World of Tomorrow,” “Sucker Punch” — tend to tank hard.

Boasting more than 2,000 visual effects shots, it’s dispiriting to think about the time, energy, planning and precision that went into “Warcraft” when the final product brings to mind those animated advertisements for iPhone app games. So good at making the most outlandish elements of his first two films seem completely credible, Jones can’t find a way to get this cartoony spectacle to soar. His heartfelt approach to the material only underlines the silliness.

Production designer Gavin Bocquet, costume designer Mayes C. Rubeo and visual effects supervisors Bill Westenhofer, Jeff White and Jason Smith lead the heavy lifting on the artisans side, since what the producers essentially purchased with the source material is a collection of locations, wardrobe, weapons, and spells.

“Warcraft” ends with a set-up for a sequel, but also the feeling that if this is what combat looks like, it’s time to give peace a chance.