“Liu Cixin's novel "The Three-Body Problem" presents the Dark Forest Theory, which posits that civilizations that reveal their existence to the universe face a higher risk of annihilation.”

In his 2008 book, The Three-Body Problem, Cixin Liu gave the hypothesis a catchy name. He describes the universe as a dark forest, where each alien society is like a fearful, armed hunter, gingerly moving forth. If that hunter finds “other life—another hunter, an angel or a demon, a delicate infant or a tottering old man, a fairy or a demigod—there's only one thing he can do: open fire and eliminate them. In this forest, hell is other people.”

The Three-Body trilogy centred around one theme: the “dark forest” theory – a cosmos where civilisations hide or strike pre-emptively, fearing others will destroy them first, and in a dark forest, every creature must stay silent to survive.

The Dark Forest Law, introduced by science fiction writer Liu Cixin in "The Three-Body Problem II: The Dark Forest," posits that the universe is a dark forest where every civilization is an armed hunter, moving like a ghost, trying to hide its tracks. Any life that exposes its existence will quickly be eliminated by others.

Basically, the Dark Forest Hypothesis, as articulated in Liu's novel, is that it's rational to destroy any alien civilization you come across: The universe is a dark forest. ... But as fascinating as the Dark Forest idea is, it makes little sense. There's no reason the Universe should work like it does in Liu's book. It's scientifically suspect, the game theory doesn't make sense, and it doesn't fit with what we observe in the real world.

In a cemetery, Luo Ji meets with Ye Wenjie, a former leader of the Earth-Trisolaris Organization (a human group that is pro-Trisolaran). During that meeting, Ye Wenjie tells Luo Ji the foundational principles of what she calls cosmic sociology.

The science fiction work "The Three-Body Problem" by Liu Cixin introduces a theory for the development of cosmic civilizations: the Dark Forest Law. "The universe is a dark forest, every civilization is an armed hunter, lurking like a ghost in the forest, doing its best to hide its traces, and any life that exposes its existence will be quickly eliminated by others."

"The Dark Forest Rule," Zhang Beihai’s assassinations, Yun Tianming’s medical suicide, Thomas Wade’s consequentialist initiatives, and many other plot details begin to suggest that what actually works is rarely what human morality suggests.

Liu Cixin's 'The Three-Body Problem' (2008) is the first book in the trilogy, introducing the Trisolaran threat but not the Dark Forest theory, which is developed and named in the second book, 'The Dark Forest' (2008). The theory explains why civilizations hide: revealing location invites preemptive destruction due to resource scarcity and lack of trust in the universe.

This is how threebody. problem author Lucian describes the dark forest theory in his second book the dark forest. he says the universe is a dark forest. every civilization is an armed hunter stalking through the trees like a ghost gently pushing aside branches that block the path. and trying to tread without a sound even breathing is done with care the hunter has to be careful because everywhere in the forest. ... there's only one thing he can do. open fire and eliminate. them in this forest. hell is other people an eternal threat that any life that exposes its own existence will be swiftly wiped. out.

I had to finish the trilogy to see just how far the author would go with his ”Dark Forest” hypothesis. I won't spoil the plot, but I was impressed that he took his idea and ran with it.

The U.N., upon learning that the aliens don’t have inner thoughts, develop the Wallfacer program and select four individuals to create secret long term plans to counter the Trisolaran threat. The hopes of the world rest on these men’s shoulders as they plan and cryogenically freeze themselves during long stretches of research.