Setup: A small fantasy world -- with about three cities, five sizable towns, typical medieval technology, a low amount of magic, and some typical monsters living in the uncivilized parts -- is plunged into an era of darkness. The darkness is not full nighttime all the time, and varies slightly, but at best it gets as bright as early dawn or sunset. I imagine it would be somewhat similar to a nuclear winter.

How would the people survive this era of irreversible darkness if it lasted hundreds of years? What kind of changes in culture, ecosystem, technology, magic would be necessary for survival?

  • $\begingroup$ Are there other races; dwarves in particular? Any other primarily subterranean would also likely have underground sources of food that could be developed on a dark surface. How cold is the world now? All real-world plants will have died off very shortly, so has anything taken their place? $\endgroup$ Sep 25, 2016 at 15:42
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    $\begingroup$ For a thorough examination of what happen when part of a world is under unnatural darkness for centuries, see Mary Gentle's novels Ash: A Secret History and Ilario, A Story of the First History. $\endgroup$ Sep 25, 2016 at 15:58
  • $\begingroup$ Is it darkness AND cold or just magically created darkness? $\endgroup$
    – SRM
    Sep 26, 2016 at 2:17
  • $\begingroup$ There will be dwarves, elves, and a halfling-like race at the start, but I'd like it to be human-focused so I'm thinking of ways to get rid of the other races. E.g. Dwarves dig so deep they are never seen again, elves mutate in savages. $\endgroup$
    – LukeN
    Sep 26, 2016 at 15:14
  • $\begingroup$ @SRM I was originally imagining that it would also get cold, but I'm intrigued by possibly having darkness but roughly the same temperature. $\endgroup$
    – LukeN
    Sep 26, 2016 at 15:16

5 Answers 5


I'm presuming that the ecosystem looks earthlike, in that plants grow, and provide the food of all animals, directly or indirectly. If it looks different to that, you'll need to explain it before you can get any useful answers.

Given that assumption, you can manage this if plants don't get their energy from sunlight. That's the fundamental problem that has to be solved: without it, everything dies, so other issues are irrelevant. It might have been the case all along, or some godlike power could have changed the nature of plants soon after the darkness fell. But the nature of the solution affects everything else.

Possible explanations for the growth of plants include:

  • They tap the elemental energy of earth.
  • The basic nature of plants is to grow, and considerations like energy are irrelevant.
  • The goddess of life and fertility is spending a lot of time making this happen, and has no time to do anything else, so some heroes are really needed to make the sun come back.

You also need to keep the world warm. Possible explanations for that include:

  • The world has a natural temperature range, and the sun wasn't relevant to that.
  • Sacrifices to the volcano gods are necessary to keep the world warm, without volcanoes erupting everywhere.
  • The god of fire, the hearth and metalwork is putting a lot of effort into keeping the world warm, because if everyone dies he'll have no worshippers and will forget how to be a smith. We really, really need heroes to bring the sun back.
  • $\begingroup$ I remember reading somewhere that if the sun disappeared, Earth would be kept warm by itself and still be able to last for another few thousand years sooo unless his planet has like an very cold environment and vast oceans of ice then... (I'm assuming most planets that support life would be earth-like, correct me if I'm wrong) $\endgroup$
    – Skye
    Sep 26, 2016 at 12:18
  • $\begingroup$ If the sun went out, it would indeed take a long time for Earth to cool down, and it would stabilise at well above the 3K of the cosmic microwave background, because there is substantial internal heat from radioactivity. But things would get a lot colder on a timescale of days to weeks. $\endgroup$ Sep 26, 2016 at 12:27
  • $\begingroup$ And then man's best hope is to move underground :D $\endgroup$
    – Skye
    Sep 26, 2016 at 12:28

One especially dramatic scenario would be for all plants to die out, resulting in a world populated entirely be 100% carnivorous animals and people eating each other, with a very rapidly dwindling population. Combining this "red in tooth and claw" ecosystem with the perpetual darkness would lead to a terrifying mood! In absolute darkness the population would dwindle way too quickly though, but it could be tempered to have an arbitrarily slow population decay rate by adjusting the amount of light the world receives (and thus the rate of extinction for plants).

Another option would be to explore alternative food webs. In the real world, total darkness still allows a few types of ecosystem. There are oceanic plumes which support a food web on chemical energy captured from the plumes by bacteria. In your world I would imagine there are highly magical point sources which emit "life energy", powering small island ecosystems around themselves.

The rest of the deep ocean runs entirely on food particles which drift down from the upper reaches (it's called oceanic snow). Filter feeders scoop this up and are eaten by predators. If the darkness in your world is caused by a cloud layer, then there could be some kind of flying or floating plants existing above the cloud deck, powering an ecosystem on the ground with discarded, rotting leaves. Detritivores like earth worms and millipedes would feed upon the leaf mold. Larger animals would eat the detritivores and mushrooms. People would eat everything. This strikes me as another very dramatic option!

Cave ecosystems largely run on debris brought in by animals like bats, which leave the caves to feed. Copraphages and detritivores like cockroaches feed off the excrement of the bats (and fungus that grows on it). Check out this piece by the amazing David Attenborough https://www.youtube.com/watch?v=UC51eymvsRA Your world could conceivably have aerial access to another realm where the sun DOES shine. Bats, birds, or flying insects might feed in the sunlit realm, then return to the realm of darkness to roost. The sunlit realm might be very tall plateaus which rise above the opaque cloud deck. For example, see the amazing tepuis https://www.youtube.com/watch?v=S9K8QcjwjYs

The last real world ecosystem I can think of are the microorganisms that live in the bedrock of the crustal plates. They have extremely slow metabolisms which are powered by chemical weathering of rocks and chemical reactions caused by the heat of the mantle. This ecosystem exists miles down into the earth. It's hard to see how your story could revolve around something like this, but maybe you see a possibility that I've missed?

Anyway, my advice is to figure out how your ecosystem is powered first. Everything else (technology, culture, ecology, etc.) will follow from that.

  • $\begingroup$ I like all the examples you gave! I'm thinking the original ecosystem was very similar to western europe, but it could definitely evolve (quickly due to magic and hand-waving). Do you think there could be some adaptations to plants to make them harvest the tiny amounts of light? (larger? different color or shape?) $\endgroup$
    – LukeN
    Sep 25, 2016 at 19:37
  • $\begingroup$ Thank you! I don't think there are any real plants which can cope with light levels that make it hard to see. I think the best would perform like an African violet - able to live on a few hours of indoor lighting a day, but that's vastly more light than you're contemplating. $\endgroup$
    – hexagon
    Sep 26, 2016 at 1:13

Noting all the great answers above pertaining to the ecosystem and food chains, I'd like to postulate a little about the human population in your world and their response to their situation.

Firstly, I think groups of people would definitely come together to solve this immediate problem from the start. Assuming this is not done by killing some evil overlord, I would guess that a small group of mages could develop a magic that would counter the effects of darkness on a local scale - perhaps just enough to sustain a small farm.

Over hundreds of years of darkness, this group of LightBringers could plausibly attain cult status, sending out envoys of monks on missions if they were inclined to charity, or securing power and riches otherwise.

Mankind by that time would become quite dependent on the LightBringers for their continued existence - without them they would quite quickly die off since they did not develop the evolved ecosystems needed to survive in a world without the LightBringers. The world reaches stability... until some bright spark somewhere (pun completely intended) discovers electricity. Zing!

Cue civil war, revolution against the secret shady practices of the LightBringers, with all the bells and whistles on. Anyway, sorry if this is horribly off-tangent: it was just too much fun to pass up.


Magic Mushrooms

In darkness, people will rely on a food source that lives the dank darkness - Fungi. Given the psychotropic nature of some species of fungi, it's reasonable to assume that new forms of magic will evolve over this period of time.


Obviously, there will be more of a reliance on fire for warmth and light. With the increased demand for firewood, there will naturally be more control and taxation on firewood. Foresters and lumberjacks will become more powerful.


Technology will improve in terms of iron-working and textiles - both crafting skills that can be performed indoors.


People will spend more time indoors, so writing and storytelling will be ever more important as a way of keeping people together and entertained.


Will tend to grow somewhat, due to what people tend to do in the dark hours and there's not much to do. Limiting the population growth may well lead to stricter couples laws (limiting how often couples may couple). The stricture may be scripture related, in coming from religious doctrine rather than through government (the Gods being harder to argue with than men).


Without sun light crops die, so no food, and plants die, so no air. You're in a pickle. But as it is a fantasy setting I suggest a fantasy answer: Some kind of magic that allows for things to thrive without sunlight, though at some cost. Maybe that cost is why the magic is low(?)

For a more environmental answer I would suggest that there are places in your world that are high enough above sea level to pierce the cloud cover (assuming cloud cover is what's happening) and your characters seek these places out to live in. Their search for light could become part of your story.


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