Currently, the most popular idea for building a hit franchise is using the shared universe concept. It’s been most successful with Marvel’s movies that cross through one another. It’s not exactly a spinoff or a sequel. Captain America, Thor and Ant-Man all have their own stories going on. But supporting characters, businesses, world events and other elements can cross over with one another or they can all meet up in movies like Avengers or Captain America: Civil War. It seems to reinforce its own popularity and the movies can come out two to three times a year so it’s easier for the audience to stay familiar with the concepts and characters. DC and Star Wars are working on attempting this idea. And it’s existed within comic books forever. But for live-action entertainment, I would argue that it was Star Trek: The Next Generation that popularized the concept and potential of the shared universe.
While Marvel and DC have been having their characters interact within a “shared universe” for over 70 years each, the idea is still relatively new for TV and film. A shared universe isn’t the same as a sequel because different protagonists can star in stories that still impact one another. And it isn’t the same as a spinoff which primarily focuses on a protagonist that used to be a supporting character on a different show or film. So yeah, we acknowledge that those ideas have existed for a very long time. But when Star Trek: The Next Generation tried things, it was a whole new ballgame.
First of all, right in the pilot episode we get a cameo from Dr. McCoy, one of the main characters from the original Star Trek TV show and at that point, still starring in the films. But the Next Generation takes place exactly 100 years after the original Star Trek show was set in its first episode. So far, that only sets it within the same continuity and is essentially a sequel. But it planted the idea right away that this was the same world, just 100 years later. It gave the writers access to all the narrative tools they cared to borrow from the original show, like transporters, alien races, phasers, the government structure, and allowed them to pick and choose what stayed the same and what changed. Klingons were now cautious allies but there were new threats like Cardassians and the Borg which had never been encountered by Captain Kirk and Mr. Spock.
It was the fact that the show brought back original series stars for guest appearances, as well as supporting characters from that show, that set it in the same universe. Scotty, Spock and Sarek all returned for a story or two. But it did not continue their original stories of exploration. It dealt with new stories like finding your place in a world that’s moving on (Scotty) or changing your carreer (Spock working as an ambassador). And the focus of episodes remained squarely on the new cast with guests providing plot momentum.
The show gave us Klingons that the Federation now had diplomatic relations with. That idea was shared with the original cast in their final movie, Star Trek VI: The Undiscovered Country which established the first steps of a peace treaty between the two governments. That occurred in 1991, during the show’s fourth season, when it was really hitting its stride. With new characters like Data and opponents like the Borg, the show was interesting in its own right, exploring new ideas that the original show hadn’t tackled. It stood on its own but was reinforced by the idea that it existed in the same story as the original show.
But it truly built the shared universe by the time Deep Space Nine, the third Star Trek show, was launched during Star Trek: The Next Generation’s final season. Captain Picard showed up on Deep Space Nine’s show. So it was no longer a one-way street of original series characters appearing on The Next Generation. Ferengi, Cardassians and the Bajoran were all explored in more depth on Deep Space Nine, even though they were originally created on Next Generation. One episode featured Deep Space Nine’s Dr. Bashir visiting the Enterprise. It wasn’t an especially good story but it showed how multiple elements were going back and forth.
Ideas like the Maquis were established across both Deep Space Nine and Next Generation, rogue elements of Starfleet that disagreed with how they were dealing with the Cardassians, and further explored on the fourth Star Trek show, Voyager. Klingons from Next Generation appeared on Deep Space Nine. Commander Riker’s clone appeared on Deep Space Nine. Next Gen enemy Q popped up on Voyager. This sharing of characters, alien races and the overall status of the government were always shared across the shows and movies. They weren’t always deep ties to the material – for instance, Worf commands the Deep Space Nine vessel the Defiant in Next Generation’s second movie, Star Trek: First Contact, but none of the rest of the DS9 crew is there – but at least it was acknowledged. It provided a template that Marvel really picked up and ran with.
The ideas became more dense by the end of the run of TV shows, which closed out with Enterprise. Enterprise was set a short time before the original series, involving mankind’s first explorations into space before there was a United Federation of Planets. And yet, it arguably had the tightest connections to the other shows. It began with space explorer Zephram Cochrane speaking to the new crew, a character explored in First Contact. Actor Brent Spiner, who played Data on Next Generation, appeared as Dr. Arik Soong. Soong was a geneticist who created superhumans thanks to genetic manipulation. This retroactively created the story for the eventual creation of original series enemy Khan and DS9’s Dr. Bashir, as well as the idea that Dr. Soong and his descendants would go on to explore cybernetics instead, leading to the creation of Data. And that’s bypassing the side effects of the Klingons stealing this research and having an accident which supposedly explains why Klingons in the original series had no head ridges but later always did. It was thanks to genetic tapering. That kind of far-reaching connection across several movies and TV shows was utterly unique at the time.
While Next Generation, both the show and the movies, share a lot in common with sequels and spinoffs, they went further than either. And that’s why they started the idea of a shared universe where characters and ideas can easily crossover.