Hard Science Fiction
Science fiction with emphasis on the "science." Seems to be popular with people who prefer simulationist RPGs and/or physics/calculus. As you may expect, it is diametrically opposed to "Soft Science Fiction."
A possible way to describe it is "a story where the fiction is informed by the science."
Major discrepancies between fact and fiction have been discussed ad infinitum. Important points include:
- Alien civilizations resembling human archetypes;
- Faster than light travel;
- Combat and stealth in space;
- Violation of thermodynamic laws.
Many would consider the very idea of a trans-galactic society beyond hard science fiction since conventional matter and physical information cannot travel faster than c, and even approaching that speed with considerable invariant mass regularly would take more energy than the universe can supply.
Jules Verne's works, when seen in the context of the time they were written, can be considered hard science fiction.
Settings with HSF elements
- Traveller is a very old example, and even its modern versions are practically impenetrable for the uncompromising rules that desperately try to simulate reality as closely as possible. Building a spaceship and spacesuit in your backyard to go have actual space adventures requires about the same skillset and level of effort as playing Traveller.
- Albedo is the work that gave us the word "furry." It also features detailed cutaway techno-porn diagrams of all the ships in the game and discussions of how the tech works for the curious, and is built on a complicated, realistic mix of politics and military action.
- Diaspora is, in many ways, a version of Traveller for the sorts of people who view dying (in or out of character) during character creation to be a bug rather than a badge of pride to filter out the riff-raff. All the physics is internally-consistent and unforgiving, and the system includes a lot of cultural and economic realism right there in the rules. The Dresden Files RPG-style communal campaign-building also helps ensure that everyone gets to do the kinds of things they want to do in the game.
- Battletech is a... contentious example, as the whole thing revolves around human-shaped warmachines, but outside of that, the game focuses on simulating believable socio-economic conditions and technology, and comes up with a believable explanation for man-piloted walker-mechs. (Namely, the real-world fact that the biological human inner-ear is far superior to anything tech can replicate when it comes to preserving balance, and the mechs require it not to fall over in the derpiest possible fashion.)
- Star Trek is the quintessential example. While not the first to the table or even the most original of the many Science Fiction settings with Hard elements in it, it is however one of the more wellknown, having very little "magical" applications. That said, things like a lot of the races of the setting conveniently being sexually compatible with humans, the "beam me up, Scotty" teleportation system (though that was only introduced because they lacked the special effects and budget for shuttle scenes, and by the time they had access to both the teleportation had become iconic) and the ability to create whatever you want by the click of a button, the setting isn't by any means truly hard.
- Mass Effect of Bioware fame is famous for the very hard background on the setting's technology, and how it treats the many different biologies of the setting's aliens. While most of the tech in the setting is based around a fictional element that would almost certainly kill whatever it came close to if it actually existed, all tech based on the element (read: all of it) makes somewhat sense. On the other hand, most of the aliens are 6ft tall and follow the human body plan (though this is probably mostly due to engine limitations), the Reapers and the methods they use to convert humans to impossibly durable warships and troops (spoilers, BTW) is less clear, and boils down to NANOMACHINES, SON.
- Transhuman Space is a GURPS/Steve Jackson Games setting that is about as hard as possible. Focuses more on transhumanism than the usual science fictionery.
- Worm claims (and attempts) to more or less be one (e.g., "precognitive" powers are actually simulations), although the mechanism by which superpowers are HSF is a spoiler. How well it succeeds is up for debate.