Dark Forest Theory

It starts with two axioms

Survival is the most important goal of every civilization
Every civilization will continue to expand and grow , but resource in the universe is limited.
With two assumption

Suspicion Chain
Technology Explosion
Lets start with a thought experiment. We assume that civilization A discovered civilization B.

Civilization A have two primary choice

Do nothing
Contact in a certain way
Now we note that we simplify this problem by categorizing two kinds of civilization in the universe.

Hostile and Friendly

Hostile civilization will attack another civilization when another civilization is discovered. Friendly civilization will only attack when is threatened.

Now here comes suspicion chain

Assuming A is friendly, however A has no way of knowing if B is friendly and vice versa.
Even if A knows B is friendly, and B knows A is friendly. How does A knows that B think A is friendly and vice versa?
Now if A knows B think A is friendly, how does A knows B knows A knows B think A is friendly and vice versa?
This is an endless cycle. And although in Earth we can eliminate the suspicion by communicating. In space, the communication is limited by the speed of light, and therefore you cannot be sure if the attack is under way while you are communicating. It is optimal not to contact. And let us be pedantic here, we note it is optimal not to contact when B is more technological advance than A as A has no way of knowing B's true intention due to suspicion chain. It is noteworthy to say that if A is more technologically advance there are no risk.

However here comes another issue. Going back to our thought experiment's second assumption. If A does nothing or proceed to contact, we note that there is a chance that technology explosion might occur in B's civilization. B might be able to surpass A technologically. Now since A has no way of knowing B's true intention, to ensure the first axiom A has only one optimal move: destroy any civilization when discovered.

This is logical.

Consider the following payoff matrix in game theory

B\A Contact(Destroy) Not Contact

Contact(Destroy) (0,0) (0, -infinity)

Not Contact (-infinity, 0) (-K, -L)

for which K is the probability that A surpass B and that A is hostile and L is the probability that B surpass A and that B is hostile.

We can see that the only clear Nash Equilibrium is (Destroy, Destroy)

Note: Obviously this is a crude way of approximating, but we can deduct from Natural Selection that there is probably only three kind of surviving civilization: Not yet detected, very good in hiding oneself, always destroy.

This give rise to the Dark Forest Postulate

The universe is a dark forest. Every civilization is a hunter with a gun. They pass quietly through the forest like a ghost. They must be extremely cautious and try their best to keep silence, because they know there are a number of hunters out there. And if a hunter discover another, no matter if he is an angel or a demon, an old or a young ...... the only thing he can do is to kill it. In this forest, others are the eternal threat. Anyone who reveals its location will be destroyed.


- Three Body Problem