With this week's news that, post-Age of Ultron, Robert Downey Jr. will reappear as Tony Stark, not in Iron Man 4, but in the next Captain America movie — likely as Cap's nemesis — it seems like an invisible line has been crossed in the evolution of movie franchises. We've gone beyond the notion of self-contained series or sequels, and entered a new phase in which universes are the primary arena of cinematic storytelling. And Marvel's not alone in this endeavor — there's the emergent DC Cinematic Universe, which began with Man of Steel, as well as the struggling Amazing Spider-Man 'verse over at Sony. Universal is rebooting the classic Monsters films as a shared universe with Dracula Unbound, Sony is somehow trying to turn Robin Hood into a series of interconnected films, and Fox is reputedly working to link the X-Men series with the new Fantastic Four reboot, as well as a Deadpool movie. Perhaps most ambitiously, Disney is turning Star Wars into a multimedia saga, with a new trilogy plus several standalone films. (I am waiting with baited breath for The Adventures of GONK, From The Journal of the Whills.) The notion of the "sequel" as a simple attempt to build on the popularity of a previous movie is pretty much over with. Modern studios need more than just "franchises" to stay afloat — they need universes.


So how did we get here?


While we think of movie sequels as something that exploded in the 1970s and '80s, series have always been a big part of the movie industry. In the '30s and '40s, there were numerous comedy and mystery series based around recurring characters, like The Thin Man's Nick and Nora Charles (1934-1947) and Charlie Chan (1931-1949). There were also series that spun-off from mostly unrelated hits; A Family Affair (1937) kicked off the Andy Hardy movies (1937-1946, with a belated sequel in 1958); Dead End (1937) spawned multiple series, including the long-running Bowery Boys movies (1946-1958). On the whole, though, they didn't drive the movie industry. That was reserved for the lavish, big-budget, AAA studio films like Gone With The Wind and Casablanca. And, with a handful of exceptions, like the Bond movies (1962-), that would remain the case until the early '70s, when The Godfather Part II (1974) kicked off a wave of high-profile, big-budget sequels that included French Connection II (1975), Exorcist II: The Heretic (1977), Jaws 2 and Rocky II (both 1978), and, of course, the movie that did more to redefine the longform franchise, The Empire Strikes Back (1980). (We could probably include 1979's Star Trek: The Motion Picture in this category as well, since it was a sequel to the 1966-1969 TV show.)


But what about movie universes? Those are a bit trickier. Often what seems to be a universe is actually a series of films that feature crossovers between characters but lack any strong sense of internal chronology. The original Universal Monsters series (1931-1945) featured the first crossover between established characters in movie history with Frankenstein Meets The Wolf Man (1943), and eventually threw Dracula into the mix in House of Frankenstein (1944) and House of Dracula (1945). But the continuity between movies is very loose, and full of errors. By the end of the '40s the studio would be playing up the crossover angle for comedy, with Abbott and Costello Meet Frankenstein. The "Shōwa" Godzilla movies (1954-1977) seem to be a better fit for a consistent universe. Godzilla, Mothra, and Rodan start out with their own movies, Marvel-style, and eventually come together to save Earth in multiple team-ups that recast them as heroes (there's even an Avengers-like mega-crossover with all the Tohu kaiju in 1968's Destroy All Monsters). But again, the chronology is vague. One movie might be set in the far-off future (1999!), but the next would be set in the modern day. And what about the canonicity of other Toho films, like King Kong Escapes or War of the Gargantuas? Ultimately, as with the Universal movies, the "universality" was highly subjective. If you were a fan, you could explain away inconsistencies and forge new connections. If you were a casual viewer, you could just thrill to the sight of all kinds of weird creatures beating each other up. If you were bored, you could change the channel.


Official media universes were surprisingly rare in movies, though by the '70s they had become common on television, thanks to the enormous popularity of All In The Family (1971-1979), and its many spinoffs, such as Maude, Good Times, and The Jeffersons. (We will avoid the terrifying TV Tropes Singularity that is the Tommy Westphall/Detective Munch Universe.) In film, however, they remained largely unheard of. John Hughes' teen movies, starting with Sixteen Candles (1984), were all supposed to be set in the same Chicago suburb of Shermer, but we never actually did see Ferris Bueller in detention with John Bender, or Uncle Buck advising Sam Baker on dating guys. The corrupt Duke Brothers from John Landis's Trading Places (1983) put in a cameo in 1988's Coming To America, also directed by Landis, but it doesn't have anything to do with the story. Who Framed Roger Rabbit? (1988) introduced the idea of characters from diverse established worlds living in the same universe — in this case, the Disney, Looney Tunes, and other assorted cartoons — but again, most viewers responded to it as a humorous scenario. Despite its potential, the universe concept didn't have a lot of traction with Hollywood filmmakers.


It would take a pair of pop culture theorists from the independent movie scene to bring the idea forward. Kevin Smith's View Askewniverse spans several different genres, from the low-key comedy of Clerks (1994), to the wacky teen hijinks of Mallrats (1996), to the more grounded drama of Chasing Amy (1997), to the theological satire of Dogma (1999). Apart from the recurring figures of Jay and Smith's avatar Silent Bob, there's no real reason why they have to be set in the same universe, but Smith, a diehard comics fan, wouldn't have had it any other way. Even more esoteric is the multiverse created by Quentin Tarantino, which started with Reservoir Dogs (1992) and Pulp Fiction (1994). From the beginning, Tarantino told interviewers that Dogs's Vic Vega and Pulp's Vincent Vega were brothers, but it gets denser and weirder than that; Mr. White, Vic's comrade-in-arms, used to be partners with True Romance's Alabama, while movie producer Lee Donowitz, another character in Romance, is the son of Donnie Donowitz, Inglourious Basterds' "Bear Jew." Some of Tarantino's other films are actually movies that exist within the "Realer Than Real Universe," like Kill Bill and From Dusk 'Till Dawn, though there is a small subset of characters who can cross over between realities, like Sheriff Earl MacGraw, who's in Dusk, Bill, and the "Realer" Death Proof. (And Basterds might itself be a movie produced by the younger Donowitz, based on his dad's WWII exploits.) Tarantino also made Jackie Brown (1997), which is set in another universe entirely, that of movies and TV shows based on the novels of Elmore Leonard. In both Jackie Brown and Steven Soderbergh's 1998 Out of Sight, Michael Keaton plays a government agent named Ray Nicollete, effectively making him the Agent Coulson of an unrealized Leonardverse. (Which, one hopes, might also include Karen Sisco, played by Jennifer Lopez in Sight, but by Carla Gugino in both her own short-lived 2003 TV series, and, under a slightly different name, in Justified.)

Of course, the casual viewer probably wouldn't notice any of this, and it was really more for the benefit of fans than anybody else. Before the universe could really catch on, the moviegoing public's notion of series and sequels had to change entirely. This change would be brought about by three major franchises, over a series of decades.


The first, obviously, was Star Wars. When the original film was released to insane success in 1977, it was assumed from the beginning that a sequel was inevitable. What moviegoers got, though, wasn't a sequel, but a saga. When Empire was released in 1980, Lucas explained that he'd planned out a long series of films going backwards and forwards in time, a trio of trilogies detailing the rise and fall of empires spanning generations. With the exception of Godfather II, directed by Lucas's friend and rival Francis Ford Coppola, this kind of storytelling ambition was unheard of in Hollywood. In the days before home video, sequels were cheap and quick, designed to exploit the viewers' memories of a hit film even if they were made without the same talents that made the original so memorable. Empire bucked the trend by reuniting Star Wars' cast, and was bigger, bolder, and more ambitious in every way than the original. It also ended on a massive cliffhanger, indicating that Lucas not only had faith in its success, but that there was an even larger story left untold. This was not how sequels were supposed to work. (Or series; the Bond movies had been around for a while at this point, but they'd completely ditched the SPECTRE/Blofeld arc — largely for legal reasons — after Roger Moore took over from Connery.) And what's remarkable is that, despite their huge popularity, they didn't change how sequels were made. Most of the big action franchises of the '80s and '90s, like Rambo, Lethal Weapon, and Die Hard, did not try to tell a bigger story with their sequels; they merely attempted to recreate and expand the established action beats of the original. There were a handful of sequels like Aliens that attempted to attack the material from a different angle, but they were largely the exception. Even the Indiana Jones sequels — well, technically one sequel and a prequel — featured relatively weak continuity, as did the Burton/Schumacher Batman movies. Star Trek offered some dramatic moments, but the series is an object lesson in "reset button" storytelling — a reminder of its origins as an episodic TV show.


Ironically, what changed the concept of "sequels" was not even, properly speaking, a sequel at all, but a prequel: Star Wars — Episode I: The Phantom Menace (1999). Today, this is a much-derided film, but its role in transforming movie franchises cannot be understated. It introduced a concept I like to think of as the necessary first installment. Basically, what this means is that the movie is made with the complete and total assumption that a second, third, and possibly further movies are inevitable. Since Star Wars is about as bulletproof as movie franchises get, it was taken for granted that, barring an asteroid strike or zombie invasion, Episodes II and III would get made. It also changed assumptions about what sequels were about. Very few movies up to this point, even big blockbusters, had been made with the assumption that a second movie would automatically follow. (One big exception: Superman I and II, though the producers would fire Richard Donner before he could finish the second movie.) Even though Lucas was thinking of making multiple Star Wars movies during the production of the first film, what would eventually be called Episode IV: A New Hope is highly self-contained. There are some unresolved plot developments and mysteries, but it's possible to fully understand the story without ever seeing another movie in the series. Episode I was, by definition, incomplete. To find out what happened to the characters, you'd have to check back in every three years. But audiences loved Star Wars, and despite lousy reviews, they made Phantom Menace and its sequels huge hits. The core appeal wasn't the lead actors, or even the story: It was the universe. And this approach would become commonplace in the six years between Menace's release and the final prequel, Revenge of the Sith, in 2005.


If you look at the biggest movies during those six years, something really interesting starts to happen. The most popular movie of 2000 was Mission: Impossible 2, starring Tom Cruise. This is the last time a traditional "action vehicle" pegged to a big-name star ends up in the top position. The most successful movies of 2001 were Harry Potter and the Sorceror's Stone and The Lord of the Rings: The Fellowship of the Ring, based on hugely popular novels, and these films, like Phantom Menace, would effectively redefine the modern blockbuster. Like Episode I, they're necessary first installments, with unresolved endings. The big sell is not the actors, like a Tom Cruise movie, or the promise of a complete, self-contained story, like Star Wars (or the vast majority of movies up until this time, including most sequels). It's the prospect of a vast, open-ended world, in which the individual movies are just cogs in a highly advanced narrative system. Previously, studios would have balked at the risk, and filmmakers would have worked to compress as much of the material as possible. In fact, original Lord of the Rings producers Bob and Harvey Weinstein insisted that Peter Jackson make the project as a single two-hour movie — that's why he and his collaborators fled Miramax for the more accommodating New Line. The popularity of Tolkien and Rowling convinced studios to take massive risks on huge productions that would cost hundreds of millions of dollars and take years to finish. When they started to pay off in a big way, other studios and filmmakers adopted the same model — Batman Begins, Chronicles of Narnia: The Lion, The Witch, and the Wardrobe, Transformers, Twilight, Avatar, The Hunger Games. In a lot of cases, these movies aren't even the best or most popular in their respective series; taken by themselves, they would be tremendously disappointing. The appeal is what's ahead: a bigger, more complex story, with bigger setpieces, badder villain, amazing revelations, and soul-shattering transformations. Even series that started off with fairly conventional first installments took a sideways turn into more esoteric (and confusing) worldbuilding, like the Matrix and Pirates of the Caribbean sequels — both of which were filmed back to back with their finales, making them, in a sense, necessary middle installments. Others, like the Craig Bond and Abrams Star Trek series, rebooted their core concepts into the new framework. And let's not forget the franchises that failed to to make it past Part One — Eragon, The Golden Compass, Beautiful Creatures, Mortal Instruments, Prince of Persia, John Carter [of Redacted] — in many cases because of first installments that didn't feel at all necessary.


Thing is, though, if you've got a universe, who needs a "series"? Why restrict yourself to one revenue stream from that source? Marvel's Iron Man was, while fun, a pretty conventional superhero movie (the phantom menace "Ten Rings" villain is pretty much a staple of the necessary first installment), and Iron Man 2 was a depressingly conventional sequel. But Thor and Captain America were something different entirely, not sequels, not spinoffs, but complements to the core Stark franchise. With The Avengers, and even more so, Winter Soldier (which is kind of a mini-Avengers anyway), they revealed the liquidity of the franchise. Nobody was stuck in a single series, and events and characters could spill back and forth between worlds without having to worry about the usual logic of sequels and spinoffs. There was no center. A vast array of characters, many of them completely unrelated to each other, could share the same cosmic stage. Tony Stark could show up in someone else's movie, without warning, as a hero or a bad guy; so, theoretically, could Rocket Raccoon or Howard the Duck. It was a comics fan's dream come true, but, like so many other things that seem at first weird or recondite to non-fans, like D&D or Star Trek, it was a surefire license to print money. Like the big, multi-installment fantasy sagas of a decade before, the studios have adopted the universe as the new lingua franca of blockbuster movies. And it's already spread beyond Marvel and DC.

Consider the Hobbit movies. Most people don't seem to like them as much as the LotR films, seeing as how they take a children's book that's barely 300 pages long and transform it into a nine-hour trilogy filled with incidents and characters that are nowhere to be found in the book. It's easy to think of them as Jackson's own version of the Star Wars prequels, an unsatisfying stew of CGI and redundant plot points. But they're not really prequels, per se. Rather, they're an expanded universe take on Jackson's version of Tolkien's story. The point isn't to explore Bilbo's story in great detail — he's hardly even in much of Desolation of Smaug — but to show another side of the cinematic Middle-Earth first revealed in 2001-2003. As a fan of Tolkien, or even the older movies, you might find them disappointing. But the central appeal is not so much storytelling or fidelity, but geography and history. Continuity. In the old days, when Frankenstein faced down the Wolf Man, or even fairly recently, when the Alien had a frank exchange of shrieks with the Predator, that didn't matter much at all. But now it's the whole point. Sequels are over. Universes are, well, universal.