[anbende]

Yes this is a reasonable way to misunderstand given the way we refer to “hard sciences” and “soft sciences”, but it does not map to the terms “hard scifi” and “soft scifi” in common usage.

It’s not exactly about rules consistency either as stated by the GP, though that’s part of it. It’s more about strong consistent application of scientific principles even theoretical or untested principles.

This is in contrast to futuristic fantasy with no real focus on the science. But futuristic or space fantasy can be very consistent just like magical systems in fantasy can be very consistent. Hard scifi has to be constrained by plausible consistent science and that science is typically a main character in the story, or even THE main character.

[tshaddox]

I don't know if it's a misunderstanding, or if usage is just very mixed and inconsistent. Both Wikipedia articles provide both definitions, and both claim that usage is sometimes contradictory and not at all rigorous.

https://en.wikipedia.org/wiki/Hard_science_fiction

> The complementary term soft science fiction, formed by analogy to the popular distinction between the "hard" (natural) and "soft" (social) sciences,[6] first appeared in the late 1970s. Though there are examples generally considered as "hard" science fiction such as Isaac Asimov's Foundation series, built on mathematical sociology,[7] science fiction critic Gary Westfahl argues that while neither term is part of a rigorous taxonomy, they are approximate ways of characterizing stories that reviewers and commentators have found useful.[8]

https://en.wikipedia.org/wiki/Soft_science_fiction

> The term soft science fiction was formed as the complement of the earlier term hard science fiction.

> The earliest known citation for the term is in "1975: The Year in Science Fiction" by Peter Nicholls, in Nebula Award Stories 11 (1976). He wrote "The same list reveals that an already established shift from hard sf (chemistry, physics, astronomy, technology) to soft sf (psychology, biology, anthropology, sociology, and even [...] linguistics) is continuing more strongly than ever."