I need an event which could make the world go from "similar to today" to post-apocalyptic in one lifetime, preferably in 20-40 years.

It needs to happen fast, because I want to focus the story on differences between the generation that experienced the apocalypse (and the world before it) and generations which were born after it.

Remnants of past technology would be great, but nothing that could rebuild the society in the foreseeable future. People would naturally try to save as much as possible, but decline must still be inevitable.

I thought about various combinations of common scenarios (war, plague, supervolcano, meteor etc), but I still can't get a sense of how would it manifest, what would happen immediately before and after and what would it take.

So, I'm looking for a scenario which:

  • kills the majority of people
  • gives no hope for rebuilding civilization in the foreseeable future
  • takes less than a human lifetime

closed as too broad by James Apr 5 at 18:08

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ Hello Zuzka and welcome to Worldbuilding! Didn't the Second World War do exactly what you are asking in a large part of Europe, from the Baltin Republics through Poland, Czechoslovakia and Hungary to Romania and Bulgaria? If was relatively short (6 years), killed a lot of people, left the countries in ruins and created the conditions where the survivors could not reconstruct the pre-war society? (Cough, something to do with Russia, cough.) The generation of my grandparents saw their world fall to pieces around them and they had to raise their children in an alien and hostile world. $\endgroup$ – AlexP Apr 5 at 17:08
  • $\begingroup$ @AlexP hmm, I think the author wants bigger damage. After WWII, even without other countries' help, civilization would certainly be rebuilt in Europe. $\endgroup$ – Alexander Apr 5 at 17:15
  • $\begingroup$ @Alexander: I'm not sure you read my comment. After WW2, several European countries found themselves in a position where they could not rebuild their pre-war civilization. Sure, they could and did build another one, different and fatally flawed; you may remember that the new civilization was so flawed that it had to be dismantled at the end of the 20th century and we had to start building again. Western Europe is not all of Europe. $\endgroup$ – AlexP Apr 5 at 17:46
  • $\begingroup$ Welcome to the site Zuzka. I have put this question on hold as you are asking the community to define your plot. Check out this page from the help center to get a better idea of how to ask questions. While we can help explain how something can happen, it is off topic to have someone come up with plot points for you here on the site. $\endgroup$ – James Apr 5 at 18:10
  • $\begingroup$ @AlexP the author did not stipulate that post-apocalypse civilization should be just the same as the old one, and neither that the new one should be any perfect (even without an apocalypse, this is imho impossible). $\endgroup$ – Alexander Apr 5 at 18:35

Alien pacification

In this scenario aliens come to our planet when we have invented XYZ. They have been watching us because we have gotten close. They have let societies grow up on planets before and they know that sooner or later these societies will develop weapons of mass destruction on a space level. This can't happen. These aliens are also humane and don't want to genocide the planet. They just want nice stone-age earthling animals.

So they show up and they are far too advanced. There is no war, there is no resistance. All major cities are destroyed before anyone even knows what is happening. After that the aliens set up a few pod replicators that create surveillance drones. These fly around and destroy anything electrical.

Humans are now locked in a time period. They can try rebuilding but anyone creating any technology is attached by the drones. The drones also will attack any place with over 1000 humans within 1 mile of each other. Cities are no longer permitted. Have fun on your planet.

  • $\begingroup$ Soviet pacification also works quite well. $\endgroup$ – AlexP Apr 5 at 17:47

Runaway Nanobots destroy all technology

This is a limited version of the "Grey Goo" nanobot apocalypse. At some point in the near future, nanobots are invented to maintain our (electrical) infrastructure. For this, they are given mobility and a distributed communication network among themselves.

Then things go wrong and the nanobots start tearing down anything electrical. All over the world. There's a massive panic, people start dying due to lack of clean drinking water and then famine, disease, violence, etc. Pretty standard Four Horsemen stuff.

There are of course parts of the world that already don't have a lot of access to electricity (like large areas of sub-Saharan Africa). These would not be affected directly, but they would not be immune to all the violence and war. Also, they are unlikely to have any contact with other continents, so your survivors may not know or care. Alternatively, in your world these countries have already developed into modern countries dependent on technology and suffer the same fate.

There is no way to rebuild because the nanobots are still active, near omnipresent and reducing anything resembling modern technology to dust.


A solar flare of geological-record proportions, combined with a coronal mass ejection beyond any previously recorded, result in an EMP-like destruction of any electronics more delicate than a heavy electric motor, along with power failures and broad destruction from voltage spikes on power lines (up to millions of volts on long runs of high tension wire).

End result: everything more modern than a steam engine fails, and almost everyone who understood technology well enough to rebuild dies in the resulting chaos (food riots, epidemics, outright wars fought with conventional rifles and grenades that don't require electronics). In the end, fewer than 10% of the population is left alive, most of them on the edge of starvation. Even if their number includes people with the necessary knowledge and skills (and it likely would) the infrastructure is gone. It would take, at a minimum, centuries to build back up from dark ages (Roman Empire technology, if not pre-Roman) -- and the easily mined metals, easily drilled petroleum, etc. are also gone, along with the alternative energy sources (taken down by the solar EMP equivalent).

The fall would give virtually no warning -- the flare radiation takes the same time to reach Earth as the light that announces it, even though the CME particles that would keep things off long enough for the fall to become permanent take a couple days -- and shutdown would take hours, at most, for the effects to spread globally. Starvation, of course, takes weeks to really kill, but food riots are never more than a few days away (food stores typically have 24-72 hours of stock on hand -- which will vanish in an hour or two when looting starts).

It's remotely possible that people in a geographically favored locale might restore basic electrical power from hydroelectric generation and remaining wiring -- but they'd have nothing more sophisticated than incandescent lights and heavy, factory-style machinery, with no computers to run them. No printing press, as type metal to make one work has long been scrapped as toxic waste. No communications, because records of how pre-electronic phone exchanges worked are lost and the equipment for plug-board switching exists only in museums in the (grossly unsafe) cities.

This would be the starting point for the rebuild.


A fast easy safe source of clean energy is found, lets say cold fusion. Everyone abandons fossil fuels and switches over. All is great for a while until an unusual solar flare happens and somehow makes all of the fusion reactors explode. Due to their size and ease they are all over civilization and in pretty much all technology.

This destroys pretty much all tech and most people and sets up huge problems for rebuilding. The survivors obviously can't rebuild things as they were since the reactors can't be trusted but the way things were before are also hard as fossil fuels are now very rare. A new different way has to be found.


Lithium resources dry up combined with a rapid magnetic reversal.

When the Earth's magnetic field flips all current electronics/gadgets/technology (which don't have any preventative protective measures, if any currently exist) become useless. Without new sources of rare metals needed for the electronics, as well as the electronics themselves needed for refining or recycling of the materials, new electronics that work in the altered magnetic field cannot be made/fixed etc.

Complicated food/transport supply networks crash within days/weeks/months dependent on how long the changing magnetic field affects any particular area (and how well-prepared certain governments are to the scenario). Mass deaths as people run out of day to day resources; starvation and riots ensue. Plenty of useless remnants of civilisation abound. Highly unlikely for civilisation to rebound very quickly. Certain individuals may be clever and ingenius enough to maintain a very few electronic resources...


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