Last weekend, DC Comics' "Justice League" opened on more than 4,000 movie screens. It was projected to sail past the $100 million mark at the domestic box office, but fell short of that benchmark — and earned less than the $122 million that Marvel's "Thor: Ragnarok" raked in just two weeks before.
In theory, "Justice League" should have helped solidity Warner Brothers' expanded universe in a way that competed more forcefully against the juggernaut created by Marvel's "Avengers" franchise. After all, "Wonder Woman" earned the second-highest U.S. gross of the year at $413 million, while "Batman v Superman: Dawn of Justice" earned $330 million at the domestic box office in 2016, and all of those characters appear in "Justice League."
In practice, however, the relative disappointment with "Justice League" has raised questions about how well other related films like "Aquaman", "Shazam" and a "Batman" standalone picture can fare.
Meanwhile, DC/Warner aren't the only ones experiencing growing pains with ambitious franchises. Earlier this year, Universal Studios made its first foray into a "Dark Universe," a franchise meant to re-introduce such classic movie monsters as the Wolfman and Frankenstein to contemporary audiences.
Yet in June, its flagship "The Mummy," featuring Tom Cruise, earned an anemic $80 million at the domestic box office. Alex Kurtzman and Chris Morgan, who were the architects of "Dark Universe," left the project in November — leading entertainment reporters to write unofficial eulogies for the entire project in their wake.
In response to an inquiry from CNBC, a Universal representative said the studio is "still on track, and viewing these films as filmmaker-driven titles."
Given that Disney's Marvel powerhouse has raked in upward of $5 billion to date, it's no mystery why rival studios want a box office cash cow of their own. That said, the underwhelming performances of "Justice League" and "The Mummy" underscore how forming an interconnected movie universe – even ones filled with iconic and popular characters — is much tougher than it looks.
An industry insider who spoke to CNBC on the condition of anonymity acknowledged the difficulty in trying to create an entire universe of interconnected characters, citing various factors like audience tastes, and a film maker's individual vision.
While moviegoers may warm to one movie's hero, they could just as easily reject a spin-off. That means creating team chemistry — as Marvel did with great success in "The Avengers," and DC is now trying to do with "Justice League" — is difficult to generate organically.
In the case of "Justice League," Andrew Selepak at the College of Journalism and Communications at University of Florida, said that part of the problem is that the movie doesn't fit the times. He said the brooding antihero embodied by Batman comes off as a tone-deaf relic in 2017.
"'Thor: Ragnarok' and other Marvel films are successful in theaters because they don't attempt to be arthouse films wrapped in capes, but live action cartoons with simple themes," he said.
"That it stars Chris Hemsworth cracking jokes and uses a Led Zeppelin song for theme music only helps."
Amie Simon, director of Marketing at Smarthouse Creative, said that in the case of "The Mummy," and the entire "Dark Universe" built from old monster-movie stalwarts, the problem may go beyond mere bad timing.
"Why is a reboot of classic Universal monsters even necessary?" she asked. "Studios can't just crank out movies and expect them to succeed based on familiar characters and star power alone."
It's tempting to wonder if movie audiences are simply tired of blockbuster franchises altogether. Yet Morgan McGregor, who runs the manicpixiefilmgirl.com movie blog, said that audiences will continue to pay to see these franchises — provided that the product is good.
"In no way are audiences tired of franchises in general," she said. After all, Marvel's properties are showing little signs of fatigue, with enthusiasm seemingly high for 2018's "Infinity War" and "The Black Panther."
McGregor said that "DC [is] more focused on big name actors and directors, than on actually creating effective plots and dialogue."
According to author and entertainment writer Christopher McKittrick, strategy matters too. He characterized the building of a successful franchise as a marathon, not a sprint. He added that both the DC Extended Universe and "Dark Universe" are prime examples of franchises being rushed out too quickly.
"Announcing a slate of four or five movies before an audience even has had the chance to evaluate a first film, as Universal did this year with its 'Dark Universe' before 'The Mummy' was even released, can be a major misstep," he said.
"Marvel has been so successful in building a cinematic universe because it was built organically, through several very well-received and financially successful movies," he added.
So, what lessons should studios take to heart if they still want to play the franchise game? Rob Edelman, a lecturer at the University at Albany, recommended first focusing on making a single, self-contained, enjoyable movie before worrying about sequels and prequels, much less about cinematic universes.
"[The movie] must be genuinely entertaining," he said. "I've lost count of the number of films I've seen that set themselves up with 'to-be-continued'-style endings, in which there is no closure. These films are frustrating, and ultimately are audience turn-offs."
Disclosure: Universal is owned by Comcast, which is also the parent of CNBC.