Over the past few decades we've gotten used to the idea of movie, TV, and other media franchises undergoing total reboots, with the creators breaking continuity with the original series to create new stories using the same core concepts and characters. It's pretty much taken for granted that whenever a new team takes over one of the non-MCU superheroes, like Spider-Man or Batman, that the new movies will have nothing to do with any of the previous onscreen iterations. Likewise, Ron Moore's Battlestar Galactica uses the same story and some of the characters from the 1978-79 ABC series, but it differs significantly in tone, style, and themes. And there are even hybrids that combine seeming reboots with established continuity, like the Abrams Star Trek movies or Days of Future Past, which are tied to the classic Trek shows and films, but take place in a timeline running parallel to the original universe, a concept that arguably dates back to the comic book multiverses of DC and later Marvel.
But what about "soft reboots" — movies or shows that take place in the original universe, but strategically ignore or downplay previous stories to push the franchise in a different direction without radically violating "established" continuity? The reboots can do this in a number of ways — by altering the style, introducing new major characters, or introducing new concepts to the core mythology that subtly — or radically — alter what the franchise is supposed to be about. On TV, Doctor Who is arguably the best exemplar of this approach — the cast, including the lead, turns over every few years, and often the format shifts as well. But it's also an example of a franchise whose mythology was built from the ground up, as most of the core concepts were established only after years — or even decades — of episodes, many of them developed by different writers.
In the movies it's trickier, because there are usually only a handful of films in which to establish the character and story elements. However, two very prominent examples come to mind. The first is The Dark Knight, Christopher Nolan's sequel to Batman Begins. Begins was an origin story and Knight is a "crisis" story, so obviously they'd be very different movies in terms of narrative. But the differences go deeper than that. Begins is a pulpy adventure story straight out of the 1930s, with a millennia-old secret society, fear gas, and a plot to control the entire world. Knight has a much smaller scope, involving mobsters, noir-ish thrill killers, and city politics. Even the styles are different: the Gotham in Begins is a pretty typical '90s-style superhero movie metropolis, with CGI skyscrapers and elevated trains. The Gotham in Dark Knight is represented mostly by real cities like Chicago, and there's even a side trip to Hong Kong to establish the movie's real-world credentials. After making a fairly traditional superhero movie that seemed overtly fantastic, Nolan obviously wanted to ground the sequel in a world that looked and felt more real, and resonated more with post-9/11 anxieties. I have to wonder that, if Heath Ledger hadn't died, Nolan might have focused the third movie on Gotham's supervillain underworld, rather than reviving the hoary League of Shadows storyline for Dark Knight Rises.
Another great example is Star Trek II: The Wrath of Khan, which completely ignores the previous movie, 1979's Star Trek: The Motion Picture (which, contrary to most people's memories, was actually a huge success). In that movie, Starfleet was presented as a civilian operation, and the Enterprise was the embodiment of its utopian mission, a state-of-the-art vessel full of gleaming surfaces and bright, cavernous spaces. In Khan, the Enterprise is presented as a rusty battlecruiser, with cramped, dim interiors, better suited as a training ship than the shiny flagship depicted in the previous movie. Starfleet itself is militarized, with more formal, structured-looking uniforms than the tunics and pajama-like onsies of TMP. And the optimism of the first movie is gone: Kirk fears he's over the hill, and there are fears of war with the Klingons — themes that will define the movie series throughout the '80s. Part of that was the influence of director Nicholas Meyer, who was not familiar with the original TV series, but appreciated the parallels between Star Trek and the seafaring adventures of C.S. Forester's fictional hero Horatio Hornblower. A lot of that was also reflective of darker trends in the real world, with a resurgent Cold War and widening generational shifts. It's a significant movie not only in that it redefined the series' direction, but was the first time a major movie franchise effectively retconned an installment out of existence for the sake of narrative clarity and continuity. And it was also a movie that was a sequel to a specific TV episode — 1966's "Space Seed" — which, as far as I know, was also a first.
It should be interesting to see how a lot of today's established franchises deal with aging — whether they go for a total reset, a la the various Batman iterations, or something more graduated. With the rise of multi-platform franchises like Marvel and Star Wars, as opposed to linear series, I'll bet we see more of the latter.
So what are your favorite (or otherwise) soft reboots?