Diamond Hard SF to Mushy Soft SF

I draw your attention to this handy chart devised by M Kazlev (I think) grading the realism of the science in SF stories. He is clear to emphasize that this is not grading the overall craft of the story, just the scientific plausibility of the props and settings.

I add this so that my compliment of THE MARTIAN by Andy Weir by calling it ‘Diamond Hard’ one can see what company he keeps. INTERSTELLAR, by contrast, is somewhere between ‘Very Hard’ and ‘Plausibly Hard.’

For the whole discussion (which I frankly thought was fascinating!) see here: http://www.kheper.net/topics/scifi/grading.html

Major CategoriesRating used hereCommon TropesA few examples
Hard Sci Fi“Present Day Tech”Cutting edge Present Day Tech, some developments and speculation, but nothing major that has not been attained today (so no AI). Basic space exploration, very near futureTechnothrillers, Allen Steele’s Orbital Decay
Ultra Hard (Diamond Hard)Plausible developments of contemporary technologies – AI, Constrained Nanotech, DNI, Interplanetary colonisation, Genetically engineered lifeforms. Nothing that conflicts with the laws of physics, chemistry, biology etc as currently understoodWilliam Gibson, Neil Stephenson, Kim Stanley Robinson’s “Mars” Trilogy, Robert Forward
Very HardPlausible developments of provocative contemporary ideas, bot nothing that conflicts with the known laws of physics, information theory, etc – Assembler Nanotech, Nano-Goo, Uploads, Interstellar colonisation, Relativistic ships, vacuum-adapted lifeGreg Egan, Linda Nagata, Greg Benford’s Galactic Center series, Stephen Baxter’s Manifold Series, GURPS Transhuman Space
Plausibly HardThe above but with the addition of some very speculative themes, some of which may well turn out to be impossible, others may be possible. Requires some modification of current understanding, but nothing that is logically impossible, or has been conclusively proved to be impossible (so no FTL without time travel) – Wormholes, Reactionless Drive, Sub-nanotech (Femto-, Plank, etc), Domain Walls, exotic matter, FTL drive with time travel, etcStephen Baxter’s Xeelee universe, Greg Bear’s Forge of God series, Orion’s Arm
FirmAs realistic as the above categories were it not for unrealistic/impossible plot devices (e.g. FTL without time travel paradoxes), although these are kept to a minimum as much as possibleAsimov’s “Foundation” Series, “Giants” series by Hogan, Vinge’s A Fire Upon the Deep and A Deepness in the Sky
MediumSimilar to the above but with a larger number of unrealistic plot devices; e.g. FTL without real explanation (ore with pseudo-explanation), alien biota in some instances very similar to terragen life, psionics, a great many alien civilizations. However still preserves plot and worldbuilding consistency, and the science is good and consistent.Niven’s “Known Space” series, Robert Heinlein’s Starship Troopers, Banks’ “Culture” novels, David Brin’s “Uplift” series, Frank Herbert’s Dune, Traveller RPG
Soft Sci FiSoftA number of unscientific themes – e.g. aliens as anthropomorphic “furries”, handwavium disintegrator guns, Alien Cultures and psychology all extremely uniform, and so on. However, still retains story consistency.Various TV series: Babylon 5, Farscape, Andromeda, Matrix, StarGate for the most part
Very SoftAs above but either even more unscientific elements (humanoid of the week, lifeless planets with beathable atmosphere, etc), and story with less consistencyVarious TV and movie series; for the most part the Star Trek Canon and Star Wars Canon
Mushy SoftAs above but even more unscientific (alien races never before encountered speak perfect English without a translator, animals too large to stand in Earth gravity (Godzilla), weapons that make energy beams without putting energy in, interstellar travel without FTL or centuries long voyage, mutants with super energy powers, etc)Godzilla, Comic Book Superheros, badly written TV sci fi, elements of some franchises