Sometimes a creator or company will strike gold. A work (film, novel, etc) may spawn sequels, adaptations to other media, and a bonanza of merchandise. Usually, it'll take place in its own distinct universe, the author having significant autonomy, or the time and place keeping it off limit for crossovers, like Star Wars, The Lord of the Rings or Harry Potter.
However, sometimes the creator or company will try to replicate its own success, and come up with creations in similar genres. The similarities are noted and sooner or later the separate creations wind up crossing over with each other—either to pool resources that are individually flagging in interest, or just to enjoy the benefits of a crossover. This new Shared Universe is a pretty perfect fit, and eventually it's seen as one giant franchise. However, at some point they may want to reboot only one piece of their mega-franchise, or adapt the simplest, most distilled aspect as it was originally envisioned. Luckily, these properties started out as their own franchise, so they can certainly stand on their own. But what you have is a modular franchise—full of properties that can be self-sustaining on their own, but also easily and even organically marketed as a unit.
See also Massive Multiplayer Crossover.
- Disney's works as a whole can kind of be considered one giant uber franchise, with sizable subfranchises for the Disney Animated Canon and Pixar's films, plus whatever else they own (like live-action films or the Disney Theme Parks) that they feel like throwing in. Disney now also owns The Muppets, Marvel Comics, Star Wars, and Indiana Jones, making them sub-franchises to the Disney brand. Most of the former 20th Century Fox properties that Disney acquired have stayed separate, but The Simpsons has been folded into the larger Disney franchise as well.
- And speaking of Marvel, the Marvel Cinematic Universe brings the Avengers corner of the Marvel U to movies, having sub-franchises for Iron Man, The Mighty Thor, Captain America and Guardians of the Galaxy, and (so far) one-off films for other heroes. And as they branch out into television and streaming service, it's not even restricted to film either.
- The Cloverfield franchise is made up of (so far) three films and a tie-in manga, Cloverfield/Kishin, that are connected by an intricate Alternate Reality Game that serves as both the Viral Marketing for the series and most of the Worldbuilding. While the films are otherwise standalone (beyond all of them having the word "Cloverfield" in the title), most of the connections between them are revealed in various websites detailing the activities of corporations and institutions within their Shared Universe. Furthermore, while it's unconfirmed, various fan theories have attempted to canon-weld the series with other works produced by J. J. Abrams, particularly the TV shows Alias and Lost and the film Super 8.
- The Avatar: The Last Airbender series has become a popular franchise that includes not only two animated series, but also several comics and even a novel and its sequel.
- The .hack franchise started with a series of four games, and it's prequel anime. Then came the novels, and the manga, and the next couple anime, then the second trilogy (now tetralogy) of games, and so on, and so forth.
- Superman and Batman are individually massive cultural icons. They're also members of the Justice League, which consists of all of DC Comics' other major superheroes — including ones like Wonder Woman, Green Lantern, The Flash, and Supergirl who are popular in their own right. So you may see these characters playing out individually, or as a combo of the company's superhero line. While, as noted below, DC's big characters traditionally do cooperate well when they meet up, the fact is that cross-title continuity just wasn't much of a thing for the first several decades of DC's existence; so its big name, old guard heroes tend to each have a very solid standing as separate franchises in their own rights (whereas the Marvel characters were all playing in the same collective sandbox almost from their inception). Heck, back before the Crisis on Infinite Earths, half the point of the DC Multiverse was to give franchises like Shazam! and Freedom Fighters (DC) each their own sandbox to play in, leaving crossovers as an occasional novelty.
- Marvel Comics is a little more complex. They will often place things under the "Marvel Super-Heroes" banner. But unlike DC's stable, they don't always play well together, and many of their most popular characters aren't even major players in the company's Justice League analogue, The Avengers. Thus, for the purposes of editors, movie franchises, or toys, they may divide the Marvel Universe into different "corners", with Spider-Man and the X-Men most often being their own distinct franchises. However, this may be changing, with both Spidey and Wolverine now included as Avenger members.
- The Disney Mouse and Duck Comics follow the same basic rule as the Disney Animated Canon (see below), with all the characters inhabiting the same universe — but Donald Duck and his family primarily stay in the Disney Ducks Comic Universe, while Mickey Mouse and his friends have the Mickey Mouse Comic Universe, with the occasional crossover. There are also comic stories that are clearly part of the same universe but don't clearly take place with either Mice or Ducks — such as Chip 'n Dale's solo comics.
- Brian Michael Bendis' Jinx and Goldfish don't appear to be part of a superhero universe, but since the stories were published by Image Comics, and Jinx crosses over with the Spawn spin-off Sam and Twitch, the stories could take place in the Image universe.
- Antarctic Press's Gold Digger and Ninja High School shared a universe for years, but since one and then the other each did Time Skips, they presumably fell out of sync with each other, and the crossovers effectively stopped.
- Beginning with Frankenstein Meets the Wolf Man, Universal Pictures started pitting many of their monsters against each other, to the point that they formed, for the most part, one cohesive universe with most of the action taking place in an Eastern German-ish Überwald setting. For years after, things like video collections, cartoons, and even postage stamps would sport a Universal Monsters logo featuring Dracula, Frankenstein's Monster, the Bride of Frankenstein, the Mummy, the Wolf Man, and the Creature from the Black Lagoon. In 1999, Stephen Sommers remade The Mummy, and upon its success combined most of the gothic monsters for 2004's Van Helsing, in the hopes of going through Universal's entire stable of beasties. It didn't work out, and neither did Universal's attempt to give another shot to The Wolf Man. Another relaunch was attempted with Dracula Untold and The Mummy (2017), with the latter explicitly intended to kickstart a full Universal cinematic universe, the Dark Universe. Unfortunately for Universal, though, The Mummy appears to have put the kibosh on that plan. The Mummy was released to poor reviews and didn't do too well at the box office, with the use of the "Dark Universe" logo before anyone cared about the Dark Universe being met with particular derision, and with the departure of producers Alex Kurtzman and Chris Morgan, plus the plug being pulled on Bride of Frankenstein preproduction, that appears to be more or less that for the Dark Universe for the time being.
- Godzilla. Obviously, the Big G is the star of the line, but Mothra is important enough for her own subseries, and pretty much anything by Toho can be worked into a Godzilla film. And, of course, the big lizard himself can be crossed over with just about anything.
- One of the more interesting examples at the Disney Theme Parks is the Journey into Imagination pavilion at Epcot (Florida). After the 3-D movie Honey, I Shrunk the Audience, a follow-up to Honey, I Shrunk the Kids, proved a hit there in 1994, the pavilion was completely rethemed to its "Imagination Institute" setting at decade's end. In the process, it became a hub for live-action Disney science-related characters via Easter eggs or more obvious references. The works thus welded are the Honey films, Flubber, the Merlin Jones films from The '60s, and the Dexter Riley films from The '70s... plus the original incarnation of the pavilion via the animated/Audio-Animatronic dragon Figment (a friendly trickster figure in this incarnation, rather than a Sidekick).
- The DC Extended Universe is DC Comics and Warner Bros.' response to Marvel and Disney's success with their film universe (see "Multiple Media" above). While their TV shows (unlike Marvel's) remain separate from it, so far it has grown to encompass Superman, Batman, Wonder Woman, the Suicide Squad, the Justice League, Aquaman, and Shazam, with plenty of others in the works.
- The Adventures of Buckaroo Banzai Across the 8th Dimension was an Unbuilt Trope parody of this concept, all the way back in The '80s when, while it was seen quite regularly in genre literature and comic books, it was practically unheard of in Hollywood filmmaking. The central gag of the film is that the viewer is watching an installment in a long-running series of pulp sci-fi movies with a backstory that is frequently referenced throughout via Continuity Nods and Mythology Gags... except that mythology doesn't exist, since this is the only work that this franchise ever produced. It effectively replicates how bizarre an individual installment in a Modular Franchise can look when viewed by somebody who isn't intimately familiar with the rest of the franchise.
- The View Askewniverse, a series of stoner comedies written and directed by Kevin Smith. In light of the success of the Marvel Cinematic Universe, they can be thought of as another Unbuilt Trope example, especially given the large number of comic book and science fiction references that Smith, a big-time fan of such, put into them. Unlike many of the examples on this list, these films take place in the real world amidst ordinary people without any overt sci-fi or supernatural elements (save for the religious comedy Dogma, which featured angels and demons as both protagonists and villains), the recurring plot threads, Continuity Nods, and Worldbuilding between films mostly concerning the day-to-day lives, interactions, and relationships of the characters.
- Professional teams are considered franchises in their own right, but the entire league its a brand name it will try to exploit—using the imagery of its various teams.
- Football goes one step further, since there's both a national league and continental confederation for any given team. So, for example, Real Madrid is part of the branding of both Spain's La Liga and UEFA's Champions League.
- Nintendo has the Super Smash Bros. series first and foremost, but other pan-Nintendo games include Nintendo Land and NES Remix.
- Super Mario Bros. has become modular after having so many successful spinoffs; besides all the games featuring Mario himself, there's the Donkey Kong series he originated from, the Wario series, the Yoshi's Island series, the Luigi's Mansion series, one-off games starring Princess Peach, Luigi, Toad, etc. And all these characters join back together for various multiplayer tiles like Mario Kart, Mario Party, Mario Golf, etc. When Rare was working with Nintendo, the Banjo-Kazooie series and the Conker games were originally meant to take place in the Mario Universe, but when the company was sold to Microsoft, that became no longer true.
- Most animation companies will eventually have all the characters from their shorts shown to exist in one large community, if only for the purposes of marketing and branding.
- Warner Bros. places the Looney Tunes characters in the same universe along with the characters from Tiny Toon Adventures, Animaniacs, Freakazoid! and Histeria!.
- Hanna-Barbera once pooled their most popular creations for Laff-A-Lympics.
- Cartoon Network did this often in-series with their early Cartoon Cartoons, which also played with the Hanna-Barbera universe: Dynomutt, Dog Wonder appeared in Dexter's Laboratory, several Dexters's characters often appeared in The Powerpuff Girls, and Johnny Bravo met (among others) Scooby-Doo. Later, the network would have the "CN City" on-air branding, in which characters from all the shows airing on the channel co-existed in the same city, with the settings for said shows revealed as being neighbourhoods within CN City or as part of the suburbs.
- The Disney Princess brand, which is primarily focused on the royal heroines of fairy/folktale-derived films from the Disney Animated Canon. While no canon work has presented the heroines together (a rejected concept for the "Pomp and Circumstance" segment in Fantasia 2000 would have done so), various direct-to-video productions, theme park shows, CDs, the live-action series Once Upon a Time, and so forth have.