List of science fiction themes

Overarching themes

Alien contact

Alterations of the human body and mind

The artificial

Artificial intelligence

Machine rule/Cybernetic revolt/AI takeover

Collective consciousness/Culture

Cosmology

Creation of the Universe

Destiny of humanity

End of the Universe

Evolution

Existentialism (individual and collective)

End of humanity

The future

Futurology

Former imaginations of the future

Global catastrophic risk

Apocalypses or worldwide disasters and new societies that develop after the event

History

Alternate history

Historical cycles: history repeating itself (either on long or short scales)

Scientific prediction of the future (e.g. psychohistory)

Secret history

Human fears

Human nature & human psychology

Identity

Isolation & alienation

Language

Alien languages (e.g. Klingon, Huttese)

All humans speaking one language

Current human languages evolving/splitting

The Sapir–Whorf Hypothesis being strongly true (e.g. Babel 17, The Languages of Pao)

Universal translators (e.g. Babel fish)

Military/conflicts

Cyberwarfare

Space warfare

Weapons in science fiction

The nature of reality

Determinism

Omega Point

Interpretations of quantum mechanics

Parallel worlds or universes

Philosophies and philosophical ideas

Political ideas & Governance

Religious ideas

Sex and sexuality

LGBT themes

Gender

Reproduction and pregnancy

Simulated reality & consciousness

Sociology and sociobiology

Technological singularity

Themes of fantasy fiction

Beings

Archailect

Artificial intelligences

Androids and Gynoid

Artificial life

Biological robot

Cyborgs

Robots and humanoid robots

Replicants

Simulated consciousness

Beings of pure mentality

Noosphere—the "sphere of human thought"

Characters

The Absent-minded professor

The Golem

The Ignorant Friend

The Mad Scientist

Redshirt

Space Nazi

Space Pirate

Super Soldier

The Wedge

Clones

Dinosaurs

Extraterrestrial life

Hypothetical types of biochemistry

Alien invasion

Astrobiology

God-like aliens

Principles of non-interference (e.g. Prime Directive)

Message from space

Living planets (both sentient and non-sentient)

Hive minds

Infomorphs—memories, characters, and consciences of persons being uploaded to a computer or storage media

Mutants

Shapeshifters

Superhumans

Superorganisms

Symbionts

UFOs

Uplifting—using technology to "raise" non-human animals to human evolutionary levels

Ancient astronaut hypothesis

Progressor

Body and mind alterations

Biohacking/Amateur biotechnicians

Artificial organs

Additional or improved senses

Remote sensing

Bio-implants

Bionics

Cybernetics

Brain transplant

Cloning

Exocortex

Genetic engineering

Super race

Intelligence amplification

Invisibility

Life extension, Biological immortality, Universal immortalism and immortality

Cryonics

Digital immortality

Mind uploading

Organ transplantation

Organlegging

Prosthetics

Memory

Memory erasure/editing

Memory sharing

Group mind

Mind control

Mind occupation

Mind parasite

Two or more minds coexisting in a body

Human and alien coexisting in a body (see Tales from the Planet Earth)

Mind swap

Mind uploading

Neural implants to directly interface with machinery

Psi powers and psychic phenomena

Clairvoyance

Precognition

Retrocognition

Telepathy

Telekinesis

Paradise engineering

Psychedelia

Resizing (size-changing, miniaturization, magnification, shrinking, and enlargement)

Shapeshifting

Teleportation

Transhumanism & Posthumanism

X-ray vision

Habitats

Artificial worlds

Alien Zoo—a zoo where humans are kept as exhibits

Arcologies—enormous habitats (hyperstructures) of extremely high human population density

Cyberspace—the new, virtual territory of societal interaction

Domed city

Endemic

Floating city

Future of the Earth

Climate change—science fiction dealing with effects of anthropogenic climate change and global warming at the end of the Holocene era

Megacity

Seasteading & ocean colonization

Pirate utopia

Reality Television

Space colonization

Colonization of the Moon

Pantropy

Other planets

Desert planet

Mars

Terraformed planets

Space stations and habitats

Underground city

Walking City

Political themes

Adhocracy

Anarchism

Anarcho-capitalism

Apprenticeship

Assassination

Capitalism

Evil corporation

Megacorporation

Neo-feudalism

Privatisation

Cognitive liberty

Communism

Decentralization

P2P system

Dystopias and utopias

Environmental pollution

Overpopulation

Technological utopianism

Totalitarianism

Ecology

Environmentalism

Economics

Economic inequality

Eugenics

Fascism

Galactic empires

Legal personality

Libertarianism

Limited-franchise republic

Mass surveillance

Militarism

Mind reading and mind control

National security state

Nepotism

Pacifism

Plutocracy

Proportional representation

Post-scarcity economy

Racism

Regulation of technology

Regulation of nanotechnology

Revolution

Slavery

Socialism

Nanosocialism

Technoethics

Bioethics

Technophobia

Techno-progressivism

Terrorism

Bio-terrorism

Eco-terrorism

Theocracy

Totalitarianism vs. Libertarianism

Treason

Wealth inequality/Class conflict/Class alienation

World government

Zero population growth

Technologies

Artificial gravity

Artificial intelligence

Asteroid mining

Astronomical engineering

Brain–computer interface

Cloaking device

Emerging technologies

Holography

Resurrection

Robots

Self-replicating machines

Simulated reality

Star lifting & stellar engineering

Stasis device

Total conversion as energy source

Mecha

Megascale engineering & planetary engineering

Megastructures

Dyson sphere

Molecular manufacturing & Nanotechnology

Molecular assembler

Alien technology

Far advanced technology for the time

Virtual reality, mixed reality, augmented reality

Infosphere

Metaverse

Weapons in science fiction

Travel

Accidental travel

Colonization of other planets, moons, asteroids, etc.

Embryo space colonization

Generation ship

Interstellar ark

Uploaded astronaut

Terraforming

Space exploration

Interstellar travel/Starships

Faster-than-light travel and communications

Hyperspace

Hyperdrive

Slipstream

Warp drives

Wormholes

Ansibles

Close to light speed

Bussard ramjets

Ursula K. Le Guin's NAFAL ships, and the Twin paradox

Much slower than light

Generation ship

Sleeper ship

Space stations

Teleportation

Teletransporter

Portals

Time travel

Alternate history: time travel can be used as a plot device to explore parallel universes. While alternate history has its own category (see above), it often occurs in time travel stories as well.

Alternate future

Time loop

Travel to the Earth's center