I plan to make a RPG setting and I want it to be as credible as possible. By that I mean that I want to be able to explain everything with science without cheating. Statistically not likely but possible scenarios are accepted, as long as there is no absolute contradiction with things we know not being possible.

In this setting, some bird species have grown an organ that emits special brainwaves. When any animal (human included) receive these waves, they override its own and it loses control of itself. At first birds were not particularly intelligent but this ability made them able to give orders such as "feed me" or "protect me", in a way subtle enough that it was not discovered by humans before it was too late.

When the game takes place, birds rule the world since centuries, keeping many humans as slaves. Free humans survive by living in places where the birds can't go (eg caves and tunnels, some the top of very high mountains where you need an oxygen supply, space stations, etc). Human mutated and as there is no more anything like globalization they separated in different species.

1) What do you think would be a realistic gap of time for the setting to occur, assuming the psychic birds appear tomorrow ?

2) Is there a way to explain that, despite the difference in structure between different human brains, everyone can be targeted and there is nothing such as "immunity to psychic waves"?

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    $\begingroup$ It's very hard to answer questions like these, where one tries to mash up a scientifically plausable world with one extreme event. Typically, when writing such worlds, you find the actual path history takes is extremely dependent on the exact implementation of the extreme event, down to minutiae that we might not pay attention to. $\endgroup$
    – Cort Ammon
    May 6, 2016 at 1:48
  • $\begingroup$ Caves might work, although really, any place a human can go, a bird can almost certainly also go. Keeping birds out, when they can suborn a human as a Trojan horse, is going to be a real challenge. Also, depending on the species, birds can fly higher than humans can live (the record is 37,000 feet, almost 10,000 feet above Everest!), and I'd love to know how humans built space stations (or maintain them, if this is in the future) when most of them are enslaved. $\endgroup$
    – Matthew
    Apr 15, 2020 at 15:14

2 Answers 2


It takes a long time for speciation:

Evolution can be extremely rapid, as shown in the creation of domesticated animals and plants in a very short geological space of time, spanning only a few tens of thousands of years. Maize (Zea mays), for instance, was created in Mexico in only a few thousand years, starting about 7,000 to 12,000 years ago.

The two examples above were of active specialization with humans consciously interacting to domesticate a product. Even in this extreme example, we're looking at 10,000 years minimum. Realistically, we're not going to have active breeding programs like we did for domestication, so it will be longer.

Without an active breeding program, speciation takes even longer:

The time frame for the evolution of the genus Homo out of the chimpanzee–human last common ancestor is roughly 10 to 2 million years ago, that of H. sapiens out of Homo erectus roughly 1.8 to 0.2 million years ago.

Given these timelines, the answer to your second question is easy, but done in two parts. The first is the short term. In the short term, you should take advantage of some structure that exists in all humans, but not in other animals:

Even at rest, the brain is very active. Different brain areas that are active simultaneously during rest form so-called 'resting state’ networks. For the most part, these resting state networks in humans and monkeys are surprisingly similar, but we found two networks unique to humans and one unique network in the monkey.

So pick one of those structures and make your magical brainwave organ target them. You wouldn't even need to name the structure.

In the long term, i.e. 2 to 10 million years, the birds are co-evolving with humans, so its highly reasonable that they would be constantly adapting their organ to have better specificity for their human slaves.


I plan to make a rpg setting and I want it to be as credible as possible.

That statement contradicts basically all of the rest of your premise.


Birds have very small brains, and think in a way which is utterly alien to us. Even if they started speaking to us we most likely wouldn't be able to follow their trains of thought (such as they are), or their instructions (if we play along with your premise of them being able to control us).

The idea that they might somehow "grow an organ that emits special brainwaves" is ridiculous. Additionally, humans would need to have "an organ" with which to receive and understand these "special brainwaves". We don't.

Ever heard the expression "If looks could kill ..."? If we could read minds, or otherwise be directly influenced by other people's brain waves that would be a big deal. We have no telepathic abilities whatsoever, so that is off the table.

Furthermore not all birds (even those of the same species) would suddenly gain this ability. Some isolated specimens would do so first, and maybe drive a human or two crazy. As the problem grew, people would start figuring out what's going on and exterminate the birds in question.

Birds cannot magically develop this ability overnight. Not even one bird could develop this ability overnight, let alone an entire group of them, or multiple species across the planet.

Once the threat was identified us humans are exceedingly good at killing things. Even if they had an amazing advantage over us, we would simply retreat and release a devastating biological weapon targeted at them. We would win this fight, hands down. (which brings up another point: there's no place on Earth devoid of birds. So I'm genuinely impressed that "Free humans survive by living in places where the birds can't go." since I can't think of such a place)

The last point I'd like to mention is that for isolated groups of humans to mutate to a noticeable degree you'd be dealing with a timeline of many thousands of years.

Answering Your Questions

For your story to be "credible" (as per your first sentence) a significant suspension of disbelief is required. I just couldn't go that far.

Since there's basically nothing short of magic which might bring this situation about it doesn't make sense to ask for a "realistic gap of time for the setting to occur". Simply make it up to suit your story, as you did the rest of your setting.

Similarly, the reason why "despite of the difference in structure between different human brains, everyone can be targeted" would be because the author says so.

There are simply no scientific reasons why that would be. You can't, on one hand, ignore science and biology, but on the other hand want scientific and biological explanations as to why your scenario is "credible".

Understand, I'm not saying that you shouldn't write your story! By all means, do so. However there's no good answers to your questions, since they're based on principles you're already rejecting in order to set up the premise of your story.

  • $\begingroup$ You don't have to take a such agressive tone, you know ? I will try to make the question more clear but please calm down and take a breath. $\endgroup$ May 4, 2016 at 15:09
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    $\begingroup$ @AnneAunyme - I made my point very calmly. My tone is not aggressive. It is however critical of your ideas, which is probably why you perceive it as such. $\endgroup$
    – AndreiROM
    May 4, 2016 at 15:12
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    $\begingroup$ "That statement contradicts basically all of the rest of your premise" is quite aggressive, as well as untrue. Also, the assertion, "Since there's basically nothing short of magic which might bring this situation about it doesn't make sense to ask for a 'realistic gap of time for the setting to occur'." Even if magic is required for one thing (two if you count avian sapience), that doesn't mean that the human reaction to this magic isn't anticipatable. This is at least as feasible as teleportation for example. $\endgroup$
    – Brythan
    May 4, 2016 at 20:34
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    $\begingroup$ @AnneAunyme I can see you are rather new to WB, so you may not have seen this sort of response before. Each of the StackExchanges has its own "flavor" when it comes to answering questions. On WB, one of the pet peeves of many individuals is questions in the form of "Explain to me what would happen if everything was exactly as it is, using science, except for this one utterly fantastical detail which changes everything... but please respond as though it doesn't change anything." It's a particularly tall challenge to weave someone else's world for them when they give the most extreme... $\endgroup$
    – Cort Ammon
    May 6, 2016 at 1:42
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    $\begingroup$ ... requirements possible. I can't say I agree with the tone Andrei used, but I do have to admit to having used similar tone myself on other answers. It's a particularly frustrating class of questions to tackle, and easy to be snippy about. I just wanted to try my best to shed light on why, in hopes that additional information might help you frame future questions (potentially about the same world) in a way which generates more of the reply you want to see. Hopefully it helps. $\endgroup$
    – Cort Ammon
    May 6, 2016 at 1:45

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