World Of Phlebotinum: Level 2 on the Mohs Scale of Science Fiction Hardness. The universe is full of Applied Phlebotinum with more to be found behind every star, but the Phlebotinum is dealt with in a fairly consistent fashion despite its lack of correspondence with reality and, in-world, is considered to lie within the realm of scientific inquiry.
Anime and Manga
- Neon Genesis Evangelion: A lot of the Applied Phlebotinum in this series involves branches of biology and engineering that neither exist in real life nor are ever likely to exist. "Metaphysical biology," for example — Doctor Kozo Fuyutsuki's specialty — is kind of like genetics, only it involves human souls instead of genes. While there is so much bizarre phlebotinum that it's impossible to keep track of what's ACTUALLY supposed to do what, it's still usually internally consistent.
- The Lensman novels: A classic pulp SF series, which originated the trope of Space Police armed with incredibly powerful and flexible weapons, and arguably, the whole Space Opera genre. Lensmen had intertialess drives, habitable gas giants (with surfaces you could land on)... it was pretty soft even when the first stories were published (in the 1930s), and since then, the march of science has made hash out of most of its assumptions. However, it is remarkably self-consistent, and it did pay respect to basic scientific principles - the FTL drive only suspended inertia, which returned when the drive was turned off. Space combat takes place in 3D. Rayguns didn't cause objects (or people) to magically vanish, but simply delivered enough energy to melt or boil them.
- The Skylark of Space series of books, also by E. E. Doc Smith. The first book kicks things off with a quantity of Unobtanium, more than a bit of Faster-Than-Light Travel, and multiple First Contacts, and the series only escalates from there.
- The Star Wars Expanded Universe is marginally harder than the films, and probably belongs in this category. The technology may fly in the face of real-world science, but at least it's consistent.
- Isaac Asimov's Foundation series. It's got FTL Travel, Deflector Shields, "atomic" versions of just about everything, Psychic Powers, and an invented statistical science called "psychohistory" which can predict the course of civilization with frightening accuracy.
- Animorphs probably fits here the best. The rules are fairly consistent (No morphs more than two hours long or they're permanent, Z-space, etc), if made up. The kids do test out their shapeshifting powers a little bit, but mainly to figure out where the rules and limitations are, such as clothes. Beyond that, they're all high-school teenagers. None of them have the information (or the time and inclination) to figure it out.
- Orion First Encounter: Fits here when not running on Rule of Funny. While there are plenty of things like ray guns, and faster than light travel, the ships still obey orbital mechanics.
- Farscape: Rubber-Forehead Aliens and even Human Aliens abound, and space travel seems to suffer from a case of Sci-Fi Writers Have No Sense of Scale. Artificial Gravity is so ubiquitous as to not merit mention, and its seems that All Planets Are Earthlike. Time Travel occurs more than once.
- Star Trek: The Original Series: Although, many aspects of the show were pretty hard sci-fi when it was created, and only seem strange now after decades of science. Though the setting is stranger than other Star Trek shows, the ships and the technology are much more grounded. That said, it features many softer elements (e.g. Rubber-Forehead Aliens, All Planets Are Earthlike, Aliens Speaking English, transporters, Time Travel, Disintegrator Ray), some of which were used because of the technical and budget limitations at the time, while others were deliberately used, invoking Artistic License.
- The Rocket Age mostly runs on Radium, which apparently allows for ships fast enough to make trips between the inner planets only take weeks and trips to Jupiter only take months. Weaponry tends to be consistently explained and logical, although the setting does of course ignore the energy requirements. However, Rocket Age also includes psychic powers and immaterial beings and offers no real explanation.
- StarCraft: A borderline case of this category. While it's certainly not as soft as Lensman Or Neon Genesis Evangelion, there are a number of scientifically questionable elements throughout, particularly found in the nonhuman races. On the other hand, most Terran technology seems, if not realistic, then plausible, save for a few elements such as gravity manipulation. Then there's Psychic Powers, which have no justification at all, but that's to be expected, considering they're a stand in for magic.
- Zone of the Enders falls pretty clearly into this category. It has a lot of things that are relatively plausible, but the presence and frequent use of metatron takes it right into this territory, especially as the player is frequently exposed to elements enabled by it.
- Stellaris. It's as realisitic and internally consistent as a Grand Strategy game has to be to work, but beyond that, it's positively dotted with space-borne creatures, inexplicable anomalies, Psychic Powers, and the odd Eldritch Abomination. Many mysteries are left pointedly unexplained. Of note: post-release development has generally tended towards softening the universe, because the developers have found the appetite for Rule of Cool far exceeds that for hard sci-fi, at least in their fandom. More Rubber-Forehead Aliens and Petting Zoo People are included, for instance, because they're statistically much more popular than Starfish Aliens.
- Destiny is a setting that verges somewhere around this, for while the Traveler's Light, the powers of the Darkness, and other esoteric abilities approach fantasy-style magic, all of it is treated in a scientific manner in-universe. While Light itself is not consistently understood, this is mostly because the characters are operating on incomplete knowledge and piecing together their history.
- A Miracle of Science is just about at the hardest end of this category — the Martian Hive Mind and the Mad Scientists contribute a lot of properly implausible tech (although the Decoherence Cannon was apparently a mundane research project), but between these we have things like gravitational slingshots and laser microphones which are ordinary modern technology.
- El Goonish Shive: The science, later revealed to be powered by magic which is then itself revealed to be governed by its own consistent rules and likely entirely analyzable,note is entirely divorced from reality but nothing if not internally consistent. Magic A is definitely Magic A. Just misses Physics Plus due to softeners handwaved by the in-universe Law Of Narrative Causality (also hinted to be one of the natural laws guiding magic), like violations of the square-cube law, the mysterious force that causes the "dramatic hair-in-the-wind effect," and, formerly, characters' ability to summon hammers for comedic effect—which has since been explained meticulously to slot neatly into the universe's rules after all.
- Rick from Rick and Morty is a powerful, universe hopping super-genius, but the show stays pretty consistent in what he can and can't do - It's explicitly stated that he can't bring back the dead, for instance. He can travel to alternate universes, though, which offers the show something of a wildcard in this regard, allowing them to bend the boundaries of the show.
Back to Mohs Scale of Science Fiction Hardness.