TLDR: how long would it take modern day humans to adapt to an incident where dungeons appear on earth and spits out monsters?

I am writing a fantasy/apocalypse novel set on modern day earth. One day, 60 dungeons appear on earth and monsters invade from it. These dungeons are different in the sense that there are seemingly infinite amount of floors and monsters in the dungeon. In the initial invasion, around 500,000 monsters come out from each dungeon.

The humans must kill all these monsters and start proactively hunting them inside the dungeon in order to avoid another invasion. Humans can also level up and get classes that make them stronger. I want the society to adapt to dungeons by establishing guilds and a system for hunters (humans with classes) to kill monsters in dungeons.

Couple of details that might matter:

• Firearms and other modern weapons only work on monsters when they are outside the dungeon. This is because monsters are creatures with mana and mana is originated in dungeons. So, they are “buffed” inside dungeons (Mana does slowly leak into earth from dungeons).

• If the monster populations in the dungeons are not curbed frequently, then an invasion can occur where they come out of the dungeon. This also happened when dungeons first appeared.

• There is a game type system; where all humans can view their status and level up by hunting monsters. You can get a class at level 10. Most civilians never achieve this and stay in single digits.

• Since there are only 60 dungeons and there are 195 countries. I have it to where the dungeons appear in the top 60 populated countries. The smaller countries are safe; for now…

• Monsters killed inside the dungeon can drop loot: magic reinforced weapons, potions, skill books, armor. Once a monster is killed its corpse will immediately dissolve into the dungeon and loot will appear randomly (Therefore no corpses can be harvested). On the lower levels, there are herbs and ore veins that can be harvested and retrieved.

So how long would it take for humans to adapt to the point where they can regularly hunt monsters and keep the monster populations down.

Edit: The dungeon cannot be destroyed. It is a portal to another space/dimension. Also there is no benefit if a monster is killed outside the dungeon. The corpse will still dissolve and there will be no loot. So invasions only cause harm.

  • 27
    $\begingroup$ Keep the populations down? Hell no. You've just described an infinite source of metals and chemicals and proteins that requires no external power or resources. That stuff has got to be farmed on an industrial scale. Think of the possibilities for carbon capture and storage, or nuclear and chemical waste disposal! It'd be world changing, and amazing. $\endgroup$ Jul 25, 2019 at 13:04
  • $\begingroup$ What kepps the Military from bombing a threaht this big into oblivion? I mean not the Monsters but the dungeon itself. $\endgroup$ Jul 25, 2019 at 13:07
  • 10
    $\begingroup$ I'm thinking you could also just set up colossal coal-fired powerstations above them, and pump the exhaust gas and fly ash down into the dungeon. It'd probably kill any monsters that needed air to breathe, and smother most of the rest. All that, and it'd be zero-carbon, too. $\endgroup$ Jul 25, 2019 at 13:07
  • 2
    $\begingroup$ @Rex_Dracones I though fictional militaries were all about using monsters as weapons themselves? $\endgroup$ Jul 25, 2019 at 13:08
  • 4
    $\begingroup$ Replace "dungeons" with diamonds and all you need is a company called De Beers that buys all the land and charges you money to hunt demons. $\endgroup$
    – Mazura
    Jul 26, 2019 at 2:57

8 Answers 8


Assuming these dungeons have appeared in countries with modern military industrial complexes

48 hours to fully contain

72 hours for the first submission for planning to automatically turn anything coming out of the dungeon into food/fuel/other usable resource. See our previous questions on dealing with zombies where half the answers either put them through a wood chipper or a rock crusher.

You see, in the real world we're far more efficient about dealing with such problems than fantasy games would have you believe.

But you want people to have access to these dungeons, not have them controlled by major industrial influences.

What you need is chaos and corruption.

Syria or Libya for example. Places where the outback is controlled not by governments and corporations but by militias and corruption. You'll have to pay a fee to go in, but you'll get in. Whether and how you make it out again, well that's another story.

  • $\begingroup$ Correct answer, upvoted. Containment will mean a wall just outside dungeon exit (maybe even a dome), with assorted modern weaponry to eliminate monsters as they come out. Syria and Lybia will end up with UN or NATO troops doing the containment. Africa might end up with uncontained dungeons if they are far from developed nations. Containment will allow scientific or scavenging crews to go in (at their own risk). $\endgroup$
    – Bald Bear
    Jul 25, 2019 at 14:18
  • 1
    $\begingroup$ @SamJoseph, remember your rules only apply inside, as soon as they're outside it's business as usual. Just a couple of feet out and concrete the whole thing over. $\endgroup$
    – Separatrix
    Jul 25, 2019 at 14:24
  • 2
    $\begingroup$ This solution would work for ordinary monsters, not Godzilla-level ones. The question does not specify how the power of monsters range, but hunting Godzillas inside the dungeon would be impossible. $\endgroup$
    – Alexander
    Jul 25, 2019 at 16:10
  • 2
    $\begingroup$ @Separatrix I doubt powerful RPG monsters avoid populated areas, more likely the reverse: Once they show up, the area is soon uninhabited, because everyone left or was killed. Basically the same result, though. $\endgroup$
    – Grault
    Jul 26, 2019 at 13:29
  • 1
    $\begingroup$ @Separatrix That assumes that all the monsters actually need is the mana source to live a happy life. Wounded and ostracized massive monstrosities would happily raid human settlements if they aren't killed by dungeoneers inside the dungeon. $\endgroup$
    – Vashkarzas
    Jul 26, 2019 at 16:08

Oh, we are going to science the heck out of those things!

As others have stated, monsters outside are not a problem, just point an A10 Warthog at them. Modern warfare is lethal on a level that no dungeon monster can possibly compete with.

In most countries this will happen in a matter of days.

Then we will send in some brave men to establish a beach head. This will just be a matter of putting in a really sturdy and lockable door some way down the corridor. The area on the outside of that door is now safe. Well, for a while. When the inevitable Really Big Monster shows up, the door should at least slow them down to the point where people can be evacuated. Make that multiple doors.

So, we now have a portal to another universe with different laws of physics, with a safe area where experiments can be run.

The world's scientists are going to be fall over each other trying to get there to test their pet theories.

Some will be studying the portal, trying to duplicate it and also how to close it in an emergency. Others will go deeper and find out just why firearms doesn't work inside.

When the best minds of the planet are all working on this, they will get answers. Maybe we will learn how to open portals of own to other realities. That would be immensely useful.

People will be asking for permission to explore beyond the door, but I really don't think most governments will allow that. Of course, with many portals to choose from, there will probably be exceptions.

Once we have figured out how to shoot things inside, and we will, the fun begins. But it will not be individuals wandering in without a clue, it will be a fully military operation where a large number of people go in, conquer areas and keep them conquered. Supply lines back to the portal will be maintained at all times.

Any loot will be taken back to the scientists for study.

With a large number of soldiers per enemy there will few level-ups. The few people who do will also be taken to the scientists for study.

Eventually we will learn how to use magic back on Earth and life will never be the same.


Most of what these people have said is correct, although they assume a lot. Depending on where you put the dungeons and the first invasion, it can go a lot of ways. For example, if that first invasion is enough to cripple the society where it started and it killed a sufficient amount of people, there could be chaos and the time to set up a basic defense for the monsters could be a while. Also, since loot doesn't fall outside of said dungeons, it might take a while before anybody figures out that going inside the dungeon might be lucrative. Also, who cares about the dungeons anymore if we can just kill them every time they show up with our guns and stuff. I say you make the guns ineffective, and the monsters drop loot wherever, this way people will understand what it takes to defeat these things and where to go to do it. I say if you leave a objective of removing these monsters forever by getting to the end of the dungeon or whatever, people will be much more cooperative, but otherwise people will make clans or something and will claim dungeons by killing anybody else who tries to go there. The only way that changes is if someone else moves them, or they find a way to make money on entrance, like Bald Bear said.

P.S. the first invasion can drop some "warning" loot or something so everybody doesn't die. Also, if this is a "video game" kinda thing, maybe giving everybody a certain thing at the beginning would be good, and based on their personality and fighting style and stuff could lead them to adapting into a class, instead of all of a sudden being in one.

  • $\begingroup$ The crippled society thing is the right answer. A postapocalytpic MadMax type group would have their hands full dealing with their local dungeon. $\endgroup$
    – Willk
    Jul 26, 2019 at 1:13

While the accepted answer is likely the closest to the truth and the most likely initial scenario as written, it's not going to make for a very exciting story. Or rather, it will make for a different kind of story.

Note My initial reference for the countries that will spawn a dungeon will be the List of countries by population from Wikipedia and the OP's statement that the top 60 countries by population will get a dungeon. Numbers in brackets indicate their rank on the population list.

Good news: Dungeons for everyone!

TL;DR -- Best guess, maybe 6 to 24 months depending on damage done to the world in the First Wave. Expect all adventurers to be either licensed by a surviving state and/or owned by a mega-corp.

Day 0: The Initial Invasion

At this point, 60 dungeons emerge on 6 continents and a horde of entities 30 million strong spew from these portals. At this point, mana starts infusing Earth -- this point from the OP is important later.

Some will no doubt be hostile and/or hungry and/or just evil by our standards. Some might be the equivalent of refugees hoping for a better life outside the dungeon. Others still might be denizens that leave to try to keep the invasion contained. The latter two points aren't really in the OP's question, but given that the dungeons are described as a portal to another place, I will assume it a fully fleshed out world down there and not just a Murderhobo Demesne.

It is also likely that not every dungeon emerges in highly populated areas of their country unless Plot dictates otherwise. Canada's (#38) for one example is likely to emerge in a fairly uninhabited area of the country as most of their population is within about 200 kilometers of the US border. Not to say people will not be affected, just that it is less likely to effect a large population immediately unless it lands on one. Australia's (#53) will also not likely fall on a major population center as another example. Also, those invaders will have to deal with the possibly hostile and/or deadly wildlife -- Australia, I'm looking at you here for the memes.

Humour point: The first class upgrade goes not to a human but a random Australian animal, probably a snake. As if they weren't deadly enough before …

Some countries like America (#3), Bangladesh (#8), France (#20) and Italy (#23) will likely have their dungeons appear somewhere relevant and disruptive regardless of where they land in their country.

Depending on each country's detection systems and how easy the dungeons are to detect, the governments of the world could be aware in minutes.

Shortly after the invasion starts, The Twitterverse explodes with the news and first-hand accounts moments after emergence of the first portals that drop in a public area with a cellular network. Other social media platforms also explode in traffic due to this. This could bring the internet slowing to a crawl at least in the immediate term. It will have the side effect of definitely alerting the world that something is up.

How bad the world suffers for it and the overall death count will depend entirely on where in the country each dungeon shows up. As one example, the UK's (#21) dungeon appearing in London, England will be a lot more devastating to the country than it appearing in the Scottish highlands. One opening near a nuclear power plant or other electrical generation plant could be devastating in a different way.

Expect at least one international incident when a portal opens close to the border of another country that won't have one. They may or may not get along in time to gang up on the dungeon to contain it.

This is where you shape your fantasy apocalypse and will set up the rest of the story. Three primary factors will determine the initial damage suffered by the world:

  • Where the portals emerge in each country
  • The amount of warning that the world will get before social media alerts the world
  • The immediate hostility/lethality of what escapes into the world.

Step 1: Containment

For the more militarily powerful countries and for the more readily accessible dungeons, forcible containment of their dungeon could takes days to a couple weeks as outlined in other answers that describe this process better than I could.

This is of course, dependent on said countries not being crippled by the first wave of denizens either by dropping on their capital city and killing/eating/replacing leadership, devastating key infrastructure that prevents a swift mobilization, or triggering something really nasty in their rampage.

Expect also at least one country to try something dangerously extreme and likely more than a little stupid to contain their dungeon.

However, any containment most likely can't last forever by the OP's question. As mana leaks into Earth, it is well possible that the range that the dungeon monsters are enhanced by the dungeon's mana will extend outside of the dungeon proper which means that base guns could get less and less effective as time goes on. This may also mean that the border of the dungeon moves outside of its threshold as the dungeon's mana in our world increases.

Countries fortunate enough to get a "friendlier" dungeon may be able to parley with a representative of a more peaceful faction of the dungeon dimensions for information and learn some of the rules that way and possible entreat for help against the more violent escapees.

Should the Internet survive, expect YouTube to explode in monster invasion videos as the Twitterverse and other social media calm down slightly. Expect film of the Japanese (#11) dungeon to be thought of as a live action anime adaptation of something and everyone trying to figure out what based on what has emerged.

Somebody will Instagram themselves holding a sword with a caption like "OMG! Where was that spider hiding THIS?" only with worse spelling.

The big change will be the state's First Drop. It doesn't have to be epic loot, but the moment a giant spider dies and a sword appears, it's Science Time!

For those countries forcibly containing their dungeons, this will either take the time needed to organize an initial extermination excursion or for the mana to become thick enough for the dungeon's edge to extend outside of its entrance.

Stage 2: Stand Back! We're Going to Try SCIENCE!

As stated in previous answers, this is where we as humans try to apply the scientific method to the Dungeons. Game designers might have a bit of a better time with some aspects of this given the video game feel of the Dungeon Dimensions.

Expect questions like: Would bullets made from the metal of a magically reinforced metal weapon be possible? If yes, would they still work on the denizens in the mana-rich zones? Can these Skill Books be used by more than one person? What do those bodies decompose into and can we use it somehow?

Expect a range of ethics and moralities to arise in dealing with the scientific research based on how people vie the Dungeon Dimension denizens. Excellent philosophical debates are also abound.

Also this is the part where we begin to discover what the leaking mana is doing to the environment as it is effectively foreign radiation seeping into the world. Does this do anything to our indigenous flora and fauna? Can any wolves from the dungeon interbreed with the wolves of our world and create viable offspring? Can we survive this mana exposure long-term?

Most importantly: Where did the straggling survivors of the First Wave go? Do governments have Shapeshifter Replacement Protocols? Just how many tentacles is too much for a single monster to have? It followed me home -- Can I keep it?

I would expect multiple Internet forums dedicated to the theories and physics of the Dungeon Dimensions … or lack thereof. This is, of course, if the Internet is still present and mostly public.

Any of the soldiers that might have gained a class at this point will likely be turned over to governmental scientists for study into that phenomenon, with results either publicly disseminated, kept carefully hidden, or leaked onto the Internet somewhere. Expect random stories on the internet to arise of civilians that have attained a class upgrade from the initial wave. They will be "recruited" for study -- method depends on country and its condition.

Also, theories will be abound as to who gets what class as well as Facebook/Cosmo quizzes to figure this out. They may or may not be accurate.

Initial small-scale expeditions begin with the goal to try and salvage the first minor items. Returning safely is more important at this point than loot.

Step 3: ???

At this point, we have at least some of the rules of the Dungeon Dimensions, as well as the outside generally contained barring a fluctuation in the leaking mana causing an unpredicted increase in monster resilience. Eventually there will be a transition from a purely military operation into something else if it hasn't already due to crippling in earlier stages. It is quite possible that this will be spearheaded by some multinational megacorporation for the purposed of exploitative profit.

Expeditions into the dungeons will be commissioned here and the first large-scale hauls brought up for examination and possible distribution. How and to whom they are distributed depends entirely on who owns the expeditions.

Step 4: Profit

Regardless of how it happens, the end results will be the 60 countries will likely end up exploiting the dungeons for profit, like the gold rush or the push to the explore the new world. Each country will do it in their own ways.

Dungeon towns will spring up where the containments were and soldiers will be supplemented by licensed adventurers. Those that cannot do the fighting will ply their talents elsewhere, supporting the dungeon towns, or continue on like nothing happened. I would expect a mix of surviving modern tech and fantasy trappings especially in the dungeon towns. Almost like a living renaissance faire at times for the dungeon towns.

I would also not be surprised if at least one or two dungeons were in too inhospitable of an area to be completely maintained and thus unleash a smaller wave of monsters to mop up every so often by forces and locals nearby.

It would be here that I would expect the truly adventurous to set up frontier villages in the Dungeons themselves should conditions be self-sufficient enough to permit it.

In addition to the dungeon looting, expect additional geopolitical conflict as countries without a Dungeon to exploit try to get their hands on either the loot from one or launch a force to forcibly take a dungeon. That or corporations trying to get monopolies on the dungeons.

The Rest of the World

Almost forget about the rest of the world. If the initial invasion did not kill you, destroy your livelihood, or cause you to emigrate to a safer place, life will go on as per normal most likely unless you have chosen to involve yourself in the Dungeon Craze of '19.

I would expect new niches in the workforce to open up as it would for any highly disruptive element introduced into the world. Farmers will still farm to provide food for the world and might have a surprising number of levels depending on their location. Mundane labour jobs will still be a thing, and office workers will still do paperwork. Topics might change, such as the guy whos child just hit Level 12 adventuring for Exploracorp or the executives discussing loot purchases over golf.

There will be tales of common folk heroes that have managed to kill enough denizens to level up assuming that you can at least get partial experience for those killed outside the dungeons and just not get loot.

The flora and fauna of our world will adapt and evolve to either use the released mana or to ensure they are immune to it. Neither will happen without losses first though. Nature will prove itself surprisingly resilient on this matter I would think. The Dungeon Denizens that escape into the world without being killed will provide new species for the world to adapt to as well as a new source for mythologies for our descendants.

  • 1
    $\begingroup$ +1 for mentioning us here in Australia. However, while snakes, spiders, box jellyfish, sharks etc get all the glamour for killing people, since the start of 2019 they have killed only a handful of people. Influenza, OTOH has 220+ deaths and rising. If the monsters are sufficiently biologically compatible to eat humans then the biggest killer on both sides will be monster diseases that humans have no immunity to and vice versa. $\endgroup$ Jul 27, 2019 at 4:22
  • $\begingroup$ That raises a point about where they appear. If it's random then the possibility of them appearing on the ocean floor is real. Given the earth's surface is 75% water there is a reasonable chance that 75% of the dungeons will appear in the oceans meaning out of 60, only 15 pose a real threat to humans. The rest drown. $\endgroup$
    – Daniel
    Jul 27, 2019 at 13:15
  • $\begingroup$ America declared that the frontier was closed when, in 1890, there was nowhere with a population of less than two people per square mile. Thing is, by that definition, parts of it have reverted to frontier. . . there are many places in America where it would be disruptive only to the small number of people living nearby until the boom town springs up. $\endgroup$
    – Mary
    Dec 30, 2020 at 0:58

Separatrix's answer above is correct, but here are more details to flesh out the story

Military will surround each entrance within days, and it will take about a month to build a proper containment facility. Basically a straight concrete tunnel with dungeon exit on one end, and a large number of guns on the other. Tunnel wall can be made thicker from outside if stronger monsters start appearing, and interior walls have to be periodically resurfaced. Also, a Stargate-style steel curtain across the entrance (or movable concrete wall).

To make things less easy, have monster teleport to random locations around the exit, rather than come out of the bottleneck exit. Then military has to build a wall around the area.

The explorer teams are sent in between monster appearances. The goal is to explore and collect valuable minerals and herbs. Teams can be military, or corporation who pay military for access. If you want small-scale adventurer bands to go in, you will need large enough dungeons so corporations mine the large deposits, while small band explore the unexplored corners.

Few reasons for firearms not to work inside. The entrance portal dissolves metal or gunpowder. Dungeon passages are narrow and curved, so you do not see the monster until it is a few meters away from you. Dungeon walls are super-hard (and irregularly curved), so bullets bounce all over the place, including back to the shooter.

People will want to establish outposts inside the dungeons. So potential for turf wars between corporations.


I think an important clarification here is the size, class, and toughness of the monsters that can emerge from the dungeons. Separatrix is correct regarding initial containment if the monsters are things like Orcs, Elves, and Faeries, relatively humanoid creatures without much size difference or armor to withstand modern weaponry. If the second or even the first waves include Kaiju-class monsters at all even modern military complexes will be hard pressed to do anything but nuke it into oblivion, destroying any and all defenses previously set up. If that monster is the kind that thrives on radiation, anything like a Godzilla, or an exotic creature that feeds directly on energy input, even the nukes will fail or make the problem significantly worse. Modern military might is all well and good, but fiction and fantasy are full of creatures that have annihilated modern military forces, requiring specialized or downright strange solutions.

Why not start out with massive armies of regular monsters, but intersperse a large amount of variety. Waves of Orcs followed by the full might of the Zerg, Mindflayers corrupting humans, night-stalkers assassinating key targets, and one or two Tarrasque or Kaiju. Once they've cleared out a large radius, or humans manage initial containment, they retreat back inside the dungeon to their respective floors. Have these waves get progressively worse until humanity's only recourse is to send troops in to try and find and stop the source, discovering both the mana management and the delay or reduction of the waves in the process. Maybe they have to kill a certain boss in order to stop the wave entirely, fighting to and killing a Tarrasque (that can only be killed by the magic spell 'Wish') which can only be killed inside the dungeon as there is no mana outside.

This timeline starts off with 72 hours initial containment, 3 or 4 weeks for exploration or discovery before the second wave bursts out, then more waves every month until they discover that killing a certain enemy inside the dungeon stops the wave altogether. I'd say that would take about 6 months of dedicated research and experimentation, along with loss of life both inside and out of the dungeon to reach this conclusion. I'd add another 6 months of verifying this conclusion and the successful repetition across all the dungeons, strongly solidifying the culture of Hunters supplying the local economy with dungeon loot as a means of making a living. After this culture is established, the defensive perimeters will erode or be taken down while corporations vie for rights to broadcast raids or dedicate resources to research dungeon mechanics and physics. 1 year total adaptation timeline.


It would depend a lot on local policies, I think that the accepted answer works well for places where there is actually a military power that is organized and efficient, otherwise it would be chaos before there is actual containment.

Take that one portal appears in 'El alto' for example (it is a city in Bolivia) which has a high density of population, the government would most likely fail to react and so would the military, and when they do it would depend a lot on the type of monsters that are on the dungeons for them do have any impact whatsoever. So a lot of deaths later, after the first world countries began to contain their own portals, they would start messing with other portals (or trying to help as they would put it), and of course most local governments would accept the their help without much options since they are in chaos.

Now, if by this point the countries that managed to contain their portals started to investigate further, as Stig Hermer's answer suggest, and I completely agree, and they discovered that the portals are a source or materials, magic, etc the countries that where helped would absolutely be in a situation of debt so the resources would most likely be controlled by a few powerful governments, and that would bring a different world order.

To answer OP's question of how long would it take for all of that, not thinking about the first worlds as most of the answers do that, but for the initial international interventions, I would say a couple of weeks after the first containment s were successful, and more if the country that has a portal that needs help is a dictatorship of some kind, or a political inclination that the helping country doesn't like...


It'd take two generations, possibly three. My reasoning is simple:

  1. Every major event that impacted a generation has repercussions; with maximum impact in the generation it occurred. Take WW1; it took two generations, maybe three to come to terms with that. WW2 took longer because it included the Holocaust, which I don't think we'll ever truly recover from.

Places that actually manage to contain or otherwise handle the invading monsters will start adapting in that generation. The next generation will likely think nothing of their new way of life, going to school alongside Orcs and Manticores. For them, it'll just be the way things are.

Just like for WW1 or 2, there will be repercussions. Hybrids will be born, like Half-orcs, with unique abilities resulting from their monster and human sides (not to mention their Classes). Speaking of Classes, they may be revolutionary. If there's a Warrior or Soldier Class, then you'll have magically enhanced fighters. If there's an Engineer Class, engineering is going to improve drastically as members of that Class gain levels.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .