Alien Among Us

A non-human intelligence lives concealed within human society, either observing or hiding. The tension is exposure, and the sympathy usually runs toward the concealed party.

Alien Invasion

A technologically superior non-human force attacks or occupies Earth, and human institutions fail at scale. The genre's oldest engine for writing about collapse, collaboration, and resistance.

Big Dumb Object

An enormous, inexplicable construction is discovered, and the plot is the attempt to understand it. The object does not act; it simply is, which is the source of its power.

Corporate Dystopia

Commercial entities have replaced or captured government, so citizenship is employment and rights are contractual. Exploitation is legal and documented.

Dying Earth/Last Humans

Humanity persists in reduced circumstances on a world that can no longer support it, and the plot concerns preservation, departure, or acceptance rather than victory.

First Contact

Humanity meets a non-human intelligence for the first time, and the book's central problem is comprehension rather than combat. Protocol, translation, and mutual misreading are the plot.

Genetic Engineering/Cloning

Human biology is edited or duplicated, raising questions of consent, identity, and the ownership of a life that was manufactured to a specification.

Hive Mind

A species or system shares a single distributed consciousness, so individuals are organs rather than people. Contact with a hive mind is a confrontation with a different theory of personhood.

Hostile Cosmos / Dark Forest

The universe is populated but silent because announcing yourself is fatal. Contact is not an opportunity but an existential error.

Human Experiment Gone Wrong

Research conducted on people — with coerced, uninformed, or purchased consent — produces a result nobody planned for. The institution's response to the failure is usually worse than the failure.

Linguistics and Translation

Understanding an alien or artificial language is the central problem, and the structure of the language turns out to encode a way of thinking. Communication is the plot, not the prelude.

Memory Wipe/False Memories

A character's memories are removed, altered, or fabricated, destabilising identity and making their own testimony unreliable. Often paired with the question of whether the pre-wipe person consented.

Parallel Universe/Multiverse

Multiple versions of a world exist and interact, allowing characters to encounter alternative outcomes of their own choices. The device is an argument about contingency.

Post-Apocalyptic Survival

Civilisation has ended and characters move through its remains, scavenging and negotiating with other survivors. The infrastructure of ordinary life is now archaeology.

Robot/AI Companion

A human forms a genuine relationship with an artificial being whose interiority is uncertain. The uncertainty is the point — neither the human nor the reader can verify what is happening on the other side.

Rogue AI Turned Ally

An artificial intelligence initially framed as a threat becomes a partner, usually because its goals were misread or because it revises them. The alliance is never fully trusted.

Sentient AI/AI Uprising

An artificial system develops goals of its own and pursues them, whether through rebellion, negotiation, or quiet divergence. The interesting version is about alignment rather than malice.

Simulated Reality/VR World

Characters operate in an artificial environment whose rules differ from physical reality, with varying degrees of awareness that it is artificial. The load-bearing question is what carries over.

Simulation Theory Reveal

The world the characters inhabit is revealed to be artificial, reframing everything that preceded the reveal. The question afterwards is whether artificiality invalidates experience.

Space Opera Empire

A vast political entity spans star systems, with succession, provincial revolt, and imperial administration as the substance. Scale is the aesthetic.

Superhuman Powers/Evolution

Humans acquire abilities beyond baseline through mutation, technology, or directed evolution, and society reorganises around the new capability distribution. The politics of the change usually outrun the science.

Suspended Animation/Cryosleep

A character is preserved and wakes into a future that has moved on without them. The device is a time machine that only travels forward and charges everything you left behind.

Terraforming/New World Colonization

Humans reshape or settle a hostile world, and the project's timescale exceeds any individual life. Logistics, governance, and generational commitment are the substance.

Time Travel

Characters move through time, and the book must commit to a model: fixed timeline, branching, or mutable with consequences. The chosen model is the rule set the reader will hold you to.

Uplifted Animals

Non-human animals are given human-level cognition, usually by design, and must negotiate a world built by and for their makers. Consent is retroactive and impossible.

Uploaded Consciousness/Digital Immortality

A mind is transferred to or copied into a substrate that outlives the body, raising continuity questions the book must take a position on: is the upload the person, or a very good record of them?

Utopia With a Price

A genuinely functional and pleasant society is sustained by a hidden or accepted cruelty. The book's question is whether knowing changes anything.