It is not enough anymore to make a gazillion dollars on a good, old-fashioned blockbuster. In today's superhero Hollywood, you must build a franchise, so that your heroes can keep making cameos, pairing off and dying for many lucrative years to come.

Marvel, Disney's hero-spewing mega-empire, has made this herculean task look easy, pocketing gobs of cash from known champions ("The Avengers") and newcomers ("Guardians of the Galaxy") alike. But the threat of a box-office bomb from its main rival, Warner Bros., for "Batman v. Superman: Dawn of Justice" - a pairing so meticulous and high-powered it looks like it was built in a lab - could highlight just how hard nailing the perfect Hollywood explosion epic can be.


Starring Ben Affleck and Henry Cavill as the namesake crusaders, the epic is already one of the most expensive films ever made, with an estimated production and marketing budget topping $400 million. And it was designed from the ground up to kick off a franchise, with comics giant DC Entertainment, that will spit out two new superhero flicks every year for the next half decade.

But "Batman v. Superman" has been hammered in early reviews, garnering an abysmal 33 percent rating on Rotten Tomatoes from more than 140 critics, including The Washington Post's Ann Hornaday, who called the two-and-a-half-hour battle "punishing . . . turgid and unsmilingly sober." A poor showing at the box office could weigh heavily on the super-films that follow, souring the franchise before it began.

"This is their big shot on goal. You assume this movie should do better than all the individual character movies: you've got huge buildup, huge anticipation," said Doug Creutz, a senior research analyst with Cowen & Co. But "if this film doesn't do well, if it doesn't get people involved in the universe, I suspect most of the other films are going to struggle. And that goes beyond the box office. It goes to how people feel when they're walking out: Were they excited about it? Would they watch more?"

Warner Bros. has long touted "Batman v. Superman" as the starting point for an unfolding and hyperprofitable superhero universe. In 2014, Warner Bros. chief executive Kevin Tsujihara told investors the studio had plans in place for 10 or more upcoming hero flicks to follow, saying "the opportunity is enormous."

The Marvel cinematic universe is the highest-grossing movie franchise on the planet, having gobbled up $9 billion at the global box office (compared with $6.7 billion for "Star Wars"). And Warner Bros. investors - knowing DC is the Pepsi to Marvel's Coke in the comic-book world - have long salivated over the potential earnings from a mega-franchise even half the size.

But gloomy signs came early. In 2014, the studio postponed the film from its summer 2015 premiere for script changes, with Tsujihara saying, "I'm extremely confident it was the right decision to make the movie better. And it's so important for the studio to get the foundation right." That left WB to close out the year with a series of costly stinkers, including "Pan," "Jupiter Ascending" and "In the Heart of the Sea."

Shares for Warner Bros. parent, Time Warner, plunged more than 25 percent last year, and have sagged another 2 percent since the reviews emerged.

Warner Bros. is famous for mega-franchises, from "Harry Potter" to "The Hobbit," so the big misses drew lots of Wall Street doubt. Time Warner chief executive Jeff Bewkes has only raised expectations, promising recently that the studio would have a historic year for film revenue, led by the Batman-Superman caper and other promised blockbusters.

It's too early to say how much money "Batman v. Superman" will take home, though analyst estimates suggest it will likely open with about $150 million across more than 6,000 screens: Good, but not stupendous. But the pressure is on. Analysts say any gross less than $800 million to $1 billion will mark not just a disappointment for the film, but a potential failure to launch for the entire franchise. ("The Dark Knight" and "The Dark Knight Rises," both lone Batman films, each grossed more than $1 billion worldwide.)

Warner Bros.'s jumbo bet on two of the world's most well-known superheroes made all kinds of sense on paper. Of the 50 superhero movies that have made more than $100 million at the U.S. box office, Warner Bros. has made 13, all but two of which were Batman or Superman flicks (the others being DC properties "Watchmen" and "Green Lantern"). Those films have pocketed WB a cool $2.6 billion since 1978 - but if "Batman v. Superman" performs poorly, the duo's future earning potential could prove deeply scarred.

Meanwhile, Disney, which bought Marvel for about $4 billion in 2009 - three years before the Big Mouse would spend another $4 billion on another franchise juggernaut, Lucasfilm, maker of "Star Wars" and "Indiana Jones" - has gotten nine films on the list since "The Incredibles" premiered in 2004, including four films in the top 10. And Disney's pantheon includes many disparate heroes, such as "Thor," "Ant-Man" and "Iron Man," with lots of potential blockbusters on the way.

Warner Bros. has spared little expense in marketing the flick, including rolling out pricey Super Bowl ads (including a bizarre meta-product placement with Turkish Airlines) and flying Affleck and Cavill to the world's second-biggest film market, China, where the stars looked mostly bewildered standing onstage with Chinese singer-actor Li Yifeng in Beijing.

The studio has also rolled out plans for a heap of DC-character films, including "Wonder Woman" (who makes a cameo in "Batman v. Superman"), "The Flash" and "Suicide Squad," premiering later this year. But they will face their own struggles, including squaring off against Disney-Marvel's upcoming epics, such as "Captain America: Civil War."

Big, booming blockbusters with Batman and Superman have fared well in Chinese markets, where the appeal of classic American popcorn fare is universal: "Comedies are local, explosions are global," Creutz said. But even a profitable take from "Batman v. Superman" could end up being not enough.

The bad reviews "are not at all what Warner was hoping for," Creutz said. "Will it stop this movie from being profitable? Maybe not. But will it get people to watch 'Suicide Squad' . . . or 'Wonder Woman' next year? I really doubt it."