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This is the Cataclysm: DDA design document. It is meant for designer-end planning and goal unity for an open ended project. It is not meant to be a user facing document! In other words, spoiler alert. Do not read this document if you have no intention of contributing to the project and do not want your play experience spoiled.

Table of Contents

Cataclysm: Dark Days Ahead is a turn-based survival game set in a post-apocalyptic world. Struggle to survive in a harsh, persistent, procedurally generated world. Scavenge the remnants of a dead civilization for food, equipment, or, if you are lucky, a vehicle with a full tank of gas to get you the hell out of Dodge. Fight to defeat or escape from a wide variety of powerful monstrosities, from zombies to giant insects to killer robots and things far stranger and deadlier, and against the others like yourself, that want what you have…

User Experience

Explore, fight and survive in an expansive post-apocalyptic game world.

The core tenet of dark days ahead is if it works in reality, it works in the game. Scavenge and craft makeshift weapons, improvise shelter, outmaneuver enemies, find, repair and drive vehicles. Deal with monsters using your brains, melee weapons, firearms, traps, explosives, other monsters, fire, and if all else fails, a truck or two.

User Experience Table of Contents


DDA is a turn-based survival RPG that utilizes a top-down, grid-based view. The graphics are either character-based or use layered tiles.

DDA presents an uncompromising survival scenario to overcome, but also presents a huge variety of options for problem solving, both of which are deeply rooted in a reality-based view of the post-apocalyptic scenario. This grounding results in sometimes unexpected inversions of gaming tropes, where storage capacity of clothing is more important than armor, or weight of highly effective gear outweighs its effectiveness.


DDA is built as a standalone executable for Linux, Windows, OSX, and Android. Ports to other platforms are welcome.

The primary platform target is laptop or desktop computers, but affordances for other platforms, such as smartphones are welcome as long as they are not invasive.


DDA has two kinds of inspirations, games and game elements that it emulates, and games and game elements that it avoids.

Games to emulate

Ultima, especially Ultima III and IV.

The player-guided exploration of the Ultima games was groundbreaking, as was the insight that the game doesn’t have to be about defeating enemies and killing the big bad guy.

Fallout Series.

Surviving in a realistic setting while scavenging for resources as your dominant means of survival is the main contribution of Fallout to DDA. Special mention to Fallout Tactics for fusing many of the concepts from Fallout and X-com games.

X-Com 1 and 2.

Early X-Com games made deep and punishing tactical turn based combat interspersed with long-term character building a reality.

Dwarf Fortress

DF is an inspiration in many ways, it takes itself seriously without being too serious, it doesn’t suffer (much) from “chosen one syndrome”, it shows that investment in game world system verisimilitude pays off once it reaches completion, and that players have a taste for punishing and deep gameplay.

Games to avoid


Suffer from “chosen one syndrome” to a huge degree. Limited ability to interact with the environment. Game world is often barely deep enough to hold up if you play as expected, any deviation from the chosen path usually causes the player to encounter shortcomings.


Minecraft suffers from “Bang rocks together crafting” to a massive degree. Crafting is evocative rather than literal, leading to absurdities like a wooden wood axe.

Dwarf Fortress

DF seems to over-invest in world building. The progress made by the game is astounding, but the lack of pragmatism around some aspects of the game are worrying. Additionally the lack of emphasis on UI is IMO a much greater barrier to players than the depth of the game, which is surmountable.

Key Features

Explore a gigantic procedurally generated world.

Unique and deep focus on the complex implications of an apocalyptic scenario.

DDA uses a hybrid turn-based system. Each action has a move cost, many of which are procedurally determined. Once actions deplete an actor’s move points, their turn ends and any other game entities act for a similar duration. Game actors receive an allotment of move points each turn based on their stats and conditions. All game entities, including the player character, monsters and NPCs use the same system.

The player character in DDA navigates a 3D grid resembling voxels. Motion is predominately within the horizontal plane, but stairs, ladders, pits, and wall climbing actions can move the player or other entities vertically as well.

The player character can see other entities in a wide area around themselves, with vision mediated by both dynamic lighting and dynamic line of sight factored in. The player is also notified when the player character can perceive noises.

The player character can attack adjacent (and sometimes nearby) enemies with melee weapons, and distant enemies with various ranged weapons.

A great deal of game progression is gated by acquisition of items. The player can scavenge items from the procedurally generated towns and cities, as well as more exotic locations.

The player is able to supplement these scavenged goods by crafting a wide variety of items, ranging from mundane cooking to advanced chemistry.

Structures provide a valuable resource as well, which can be found and modified or constructed from scratch.

Vehicles in various states of repair litter the world, and can be driven, repaired and modified.

NPCs can form factions either independently or with the player.

Players can acquire and install bionic modules that give them abilities unheard of in unaugmented individuals.

Alternately, the player can more directly abandon their humanity and mutate into an entirely different kind of creature.


The player character can perceive their surroundings by sight, hearing, smell and touch.

Sight is managed by dynamic field of view and lighting systems, and works over a relatively long range, ideally approaching real-world view distances.

The player receives a rich set of auditory cues from their environment, ranging from footsteps and combat noises to environmental sounds.

A normal humans sense of smell is remarkably poor, but can still alert the player to otherwise unperceived dangers.

As a last resort, a player robbed of their sense of sight might still navigate by their sense of touch.

Additionally, the player has a limited memory of the terrain they have explored.


There are many options for causing damage in DDA, but unlike many games, DDA allows the use of a huge number of very suboptimal weapons, and most weapons have tradeoffs.

Firearms are highly effective and operate at range, but use limited ammunition, are universally uncraftable and cause significant noise to attract enemies.

Other ranged weapons like bows and crossbows trade a great deal of range and damage output for craftable ammunition and less noise when fired.

Melee weapons are often craftable and require no consumables, but have limited damage output, place the player in danger, and consume stamina rapidly when used.

Any item the player can pick up can be thrown, with wildly varying results based on player and item stats.

Unarmed combat is possible, but is even more dangerous than armed melee combat, and usually very ineffective.


The player character is expected to obtain the vast majority of their possessions by scavenging items made before the cataclysm. With the vast reduction in population, the surplus of durable goods available to each survivor is staggering.

In general, goods should be distributed in a way representative of how they would be distributed in reality, and if this negatively impacts game balance, other game aspects such as placement of enemies should be adjusted to bring things in balance rather than adjusting the placement of items.

This results in a glut of marginally useful resources, but scarcity of ideal resources.

For example cars are extraordinarily common, but robust and functional cars that are both in full working order and not surrounded by dangerous enemies are rare.

Likewise improvised melee weapons appear in vast numbers, but quality melee weapons and powerful firearms and ammunition are somewhat harder to come by.

Clothing is totally ubiquitous, but an article of clothing that improves on the player’s current ensemble and fits properly is cause for celebration.


The player can accumulate raw materials and tools to craft a wide variety of items to supplement what they scavenge.

Skill,tool, raw material and time requirements to craft items reflect the parameters of crafting the corresponding item in reality.

This places many useful items out of reach of most survivors, in particular staples such as electronics internal combustion engines, most firearms and gunpowder are out of reach.


The player can also build and modify permanent structures, providing shelter from both the environment and marauding monsters.


Scavenged or built, vehicles provide a trump card of sorts for the player, providing mobility, storage and shelter all at once, at the cost of significant upkeep.

Pre-cataclysm vehicles are modeled on existing real world vehicles.

The survivor can repair, modify and even build vehicles from scratch, but the quality is never the same as the original.


The player can acquire Compact Bionic Modules via various means and install them in their own bodies. Once installed, these modules can provide capabilities unheard of in the unaugmented, but at the cost of pervasive tradeoffs due to side effects inflicted by the bionics. Bionics must also be supplied with power by installing battery modules and some kind of charging module. The most straightforward power source is a cable charging system that can rapidly refill the player’s reserves as long as they arrange for an external source of power, but other modules can provide a trickle of power from various other sources.


Various mutagenic substances exist that can manipulate the player’s own body structure, either helping or hindering the player’s abilities in unpredictable ways. Some variants of these substances can direct the progress of the mutation in a direction more or less advantageous to the player.

Reward System

Cataclysms reward system is built around roleplay, survival and exploration.

The key concept of the game is, “what would you do in the Cataclysm?”, and the game allows you to answer that question in a bewildering number of ways.

The goal of game difficulty is to start out with survival being difficult, and get steadily more difficult over time, requiring mastery of a succession of game systems in order to continue to survive and thrive.

Acquiring mastery of the game sufficient to overcome this difficulty curve is the primary form of advancement for a player.

Cataclysm also contains a vast amount of content to explore and discover, rewarding the player with a constant stream of this content, combined and re-combined over and over by procedural generation.


The core message to Cataclysm is that we are all cogs in a massive, uncaring universe.


The primary setting of the game is present-day (2019 as of the time of writing) Earth. The current setting is New England in the United States, but that is not a core value, and there is interest in expanding the game to other regions.

Super-technology exists, but it is mostly restricted to secret lab facilities and military special forces. See the dedicated technology page for more information on what is specifically appropriate to the setting.

That all changed during the cataclysm, a several day long event where horrors from other dimensions flooded into the world, destroying, killing and in some cases creating, rendering the world almost unrecognizable.

After the Cataclysm, the invasion ebbed, leaving humanity crippled but not completely destroyed. Some of the invaders remain, carving out niches for themselves, but most retreated elsewhere.

The Cataclysm:DDA game world is very much modeled on the real world, with similar geography and demographics. Balance is adjusted by placement of otherworldly or other fictional elements such as zombies and robots in addition to natural hazards.



Dense urban centers present a great deal of risk, and a great deal of reward for survivors.

Zombies or other previously-human forces tend to congregate in these areas, rendering them extremely dangerous by sheer numbers if nothing else.

On the other hand, cities are where most of the resources of the previous civilization are, ready for the taking for anyone who can survive the horde.


Small towns represent a good risk vs reward for early game characters. Zombies or other monsters are attracted to previous population centers, but the smaller ones will not attract very large populations. On the other hand, the available loot is significant, but will be lacking in exotic and high-end gear such as technology, tactical clothing, and weapons.

The primary risk is attracting an entire town full of zombies by making too much noise.

Towns present ample opportunities to maneuver, break line of sight, hide, and set up ambushes, but present many opportunities for an unwary survivor to become cornered.

If a survivor can clear an area, food, water, tools, weapons and shelter are all readily available, even to a survivor with no particular survival skills.

Vehicular access to towns is ample due to the road network, and only significantly hampered by hordes of undead and the occasional abandoned or wrecked car.


Fields are wide open and contain sparse resources.

Threats are few and far between, but difficult to escape except by outrunning them.

Vehicles with basic off-roading capabilities can navigate fields with ease, but it requires more ability in inclement weather.

Fields are ideal building sites for shelters, but do not supply the resources for construction.


Hills present both opportunities and danger. They provide both the player and enemies ample opportunity to hide, which is mostly to the player’s benefit unless heavily outnumbered.

TODO: enemies specific to hills? Caves?


Forests present a different set of challenges for the player. On one hand there is a huge amount of space to lose oneself in, and huge amounts of resources available for the taking if you have appropriate skills and equipment. On the other hand forests are just as deadly to the unprepared as a city full of zombies due to exposure and starvation.

Tactically forests provide a great resource for evading pursuers by breaking line of sight by using the dense growths of trees and underbrush, but at the same time the player might be the one ambushed.

Enemies in forests are less pervasive than in towns and cities, but can still occur in dense pockets.


Without any form of water borne vehicle, rivers represent a hard barrier to player movement. While an unencumbered player can likely swim across a river, that leaves them vulnerable once they reach the other side.

With a water-borne vehicle, the player may achieve relative safety, but at the cost of limiting their ability to access many resources.

Rivers provide a natural source of both water and some food in the form of fish, but no access to materials for crafting.

Events of the Cataclysm

This section is to describe exactly ‘what went down’ in the Cataclysm, in the official Word of God sense. As part of the design philosophy, it is important that not all events be clearly explained to players. This is a world where exploration unlocks the story, and certain elements should be kept mysterious. It’s very unlikely that the motivations of long-zombified scientists will ever be fully made clear.

Spoiler alert. This section will contain many lore spoilers for elements that are meant to be mysterious or hard to learn in game.

Human Factions and Organizations

This section should be used to discuss both existing and deceased major factions, but it is primarily for factions forming post-cataclysm.

General Philosophy

When creating a faction in Cataclysm, consider the following:

  • All factions were part of the same overall culture only a few months ago. We’re not at a Mad Max: Fury Road stage yet, and if anyone’s acting that way they’re probably basing it on a major motion picture.
  • No faction should be “good”. Everyone is in this for themselves, everyone is scared, everyone’s first goal is not being eaten by zombies and their second goal is making it to the next winter. There is no time for altruism.
  • No faction should be “evil”. No one is the villain of their own story. Raiders may not be nice, but they believe they’re doing what they need to to survive in this harsh world.
  • Factions should avoid having a single “schtick”. The Free Merchants are merchants who believe in a free market, but that’s by far not everything they stand for. Think about what the average member of your faction does in their day to day life, and remember they can’t spend all their time just thinking about how much they like the free market, or cannibalism, or whatever your cool initial idea was. Expand.

Established Factions

These are descriptions of factions that are already in the game.

Free Merchants

“A conglomeration of entrepreneurs and businessmen that stand together to hammer-out an existence through trade and industry.”

Description: The Free Merchants are the remnants of “6 busloads of office workers and soccer moms” after the courageous people died fighting zombies. The survivors want to fortify their evacuee center of a base and survive as a trading hub.

They have a lifeboat mentality at this point, and their lifeboat is full. They are not charitable or nice and they pretty much require that people be able to pull their own weight or be abandoned.

Structure: The upper floor of the Evac Center is staffed by the few remaining combat capable people, while the rest live in the basement.

They’re nominally a democracy on a town hall model, though currently there’s an emergency manager for the first year or two post-Cataclysm.

Goals: Survive through trade.

Size: 60-160+ people?

Attitudes: Allied to the Old Guard as the last remnants of military force and organized government. The Tacoma Commune is an allied off-shoot. Trades with the Robofac, random scavengers, God’s Chosen, the Great Library, the Campus, the Brotherhood of the Tentacle, Strongarm Survivalists, Marloss Evangelists, and Fence Men. Preyed on by the Hell’s Raiders.

Opposed to Mycus, triffids, zombies, and nether creatures, though has no ability to take the fight to them and can barely defend itself against zombie hordes.

Mildly anti-mutant. Neither for or against augmentation. Doesn’t quite get that the Marloss Evangelists are mutants.

Bases: Controls an evacuee center. The Tacoma Commune is a farm project on a nearby ranch.

Trade/Economics: Has a robust internal economy, using specifically stamped US greenbacks as scrip. Honors their scrip, however it comes to them. Will buy eCards at a huge discount and sell them at a significant discount. Will buy money bundles at a premium (compared to their value as paper).

Missions (fairly complete): Deal with monsters and bandits, get parts for the center, help the Tacoma Commune.

Hell’s Raiders

“The largest gang of hooligans and bandits that preys upon other survivors. Even if you have no gear, there is always a need for slaves and fresh meat.”

Description: The Hell’s Raiders are a collection of smaller gangs, some of which existed before the Cataclysm. Much of the membership was already willing to commit armed robbery or more violent crimes, and their attitudes haven’t changed now that law enforcement is defunct and zombies roam the land.

Structure: Most gangs are led by a boss with an aptitude for leadership and violence. The members consist of former criminals, along with some desperate people who figure having a rough bunch of thugs on your side is a good survival strategy. Slaves round out the gang structure and perform menial labor, gardening, and other low risk but necessary work.

The gang leaders themselves are led by a junta of fairly nasty mutants and augmentees who view themselves as Nietzschean ubermensch with a Will to Power (not all of them take this view explicitly, but that’s the general attitude). They are the post-Human rulers of a brave new world. Psychopathy is common, and at least a few are post-Threshold mutants with sapiovore. At least some of these people were involved in creating the Cataclysm, though not intentionally. Some of them are looking for other post- and trans-humans to serve as lieutenants.

Goals: The junta leadership seeks power and are willing to do what it takes to get it. In their zero-sum worldview, other powerful factions mean less power for them, so they seek to destabilize the other factions, but they also seek to control or destroy monster factions like the Mycus, the triffids, and the mi-go.

Most gang members want to survive and be comfortable.

Size: Dozens of gangs. Gangs range from 2-3 people to 40+. The leadership junta has 4-7 members and fights among itself with some regularly and/or gets betrayed by ambitious underlings.

Attitudes: Hostile to the Old Guard, as the other remaining powerful human faction. Individual gangs prey on the Free Merchants, Tacoma Commune, Farm Survivalists, Strongarm Survivalists, Gods Chosen, the Campus, and the Great Library. Performs limited trade with the Robofac. Generally friendly with Fence Men. The leadership despises the Neo Natives but individual gangs sometimes trade with them. Some gangs prey on the BOTT, but the leadership would prefer to recruit the more promising members. Marloss Evangelists sometimes poach individual gangs or even junta members, but the junta can’t quite decide if Marloss berries are a path to power or not.

Generally pro-mutant and pro-augmentation; post-Threshold mutants or powerful augmentees are more likely to be recruited than enslaved.

Generally hostile to the Mycus, triffids, zombies, and nether cults.

Bases: Individual gangs prefer to take over existing buildings, especially prepper cabins, LMOE shelters, apartments, or military outposts and bunkers. Some gangs have built forts. Any given lead has a base in a LMOE shelter, semi-functioning lab, or military outpost.

Trade/Economics: Has a fairly robust internal economic system based on precious metals, but no formal currency within the first year. Favored allies (the Fence Men basically) can also trade gold/silver with them. Other people get promissory notes to round out barter, with no guarantee that the promissory notes will be honored in the future. The double-dealing nature of the Hell’s Raiders will cause them problems in the future.

Missions: Spy on Free Merchant and Tacoma Commune caravans, subvert the Old Guard, destroy fungal infestations, destroy triffids.

Note: Current members of the Hell’s Raiders shoot the player on sight, so if they’re going to be developed as a real faction, that needs to change.

Old Guard

“The remains of the federal government. The extent of their strength is unknown but squads of patrolling soldiers have been seen under their banner.”

Description: The Old Guard claims to be the remnants of the US Federal government, with an armada of ships in the Atlantic Ocean and a few walled off cities near the coast. In practice, there’s a pair of Old Guard agents at the Evacuee Center working with the Free Merchants, and a few squads caught in the Necropolis.

The Old Guard, on the surface, seems like the “good” faction, but they’re making claims they can’t support and are stretched way too thin. Their leadership also caused the Cataclysm, so it’s not obvious why anyone would want to put them back in control.

Structure: Practically speaking, the Old Guard is a support network that can provide limited supplies and goods to independent contractors and Federal Marshals who perform necessary tasks.

Goals: Undo the Cataclysm, or failing that, re-establish civilization under the Old Guard’s control.

Size: Theoretically, tens of thousands of people. Practically, a few dozen.

Attitudes: Friendly to any organization that accepts Old Guard guidance and seeks to stabilize the Cataclysm. They’re on good terms with the Free Merchants, Tacoma Commune, God’s Chosen, the Great Library, and the Campus. Opposed to the Fence Men, Hell’s Raider, Neo-Natives, and Bravo Deserters. Wants to establish control over the Strongarm Survivalists, Farm Survivalists, and Robofac, and would be willing to use force to settle the issue. To the extent that the Old Guard understands that Marloss Evangelists are a front for the Mycus, they’re against them.

Completely neutral on the subject of mutants and augmentees.

Explicitly hostile to the Mycus, triffids, zombies, and nether cults.

Bases: The Old Guard has outposts at the Evacuee Center.

Trade/Economics: The Old Guard is the US government, and thus thinks that trade should be handled via US greenbacks (money bundles) and eCash. The reality of the Cataclysm means that there’s been 1000% inflation, so while they technically honor eCash, they don’t pay much for it.

Missions (partially complete): Deal with bandits, investigate labs, rescue soldiers from the Necropolis, bring Farm/Strongarm Survivalists into the fold.

Resources: The key resource of the Old Guard is their fleets. Due to the isolated, regimented and self-sufficient nature of naval vessels (including merchant vessels), there was a vastly higher survival rate among in-transit ships than among the general population. While the fleets took losses from many sources, there are a number of fully-crewed and operational ships, including some very large vessels. This resource comes at a great cost however, the manpower required to operate and maintain these vessels accounts for the majority of the Old Guard population, and the resources they require is an unsustainable drain on the faction.

Development Direction: The major challenge facing the old guard immediately after the Cataclysm is extracting as much value as possible from the fleet while decommissioning it. Each remaining ship can either be operated as a combat vessel at great resource cost (food, equipment, provisions, fuel and manpower) or decommissioned to provide a core around which a community can be built. Even the smallest ship has a large diesel engine that can be configured as a generator, as well as secured storage facilities, sleeping berths, stocks of ammunition and weapons, and various facilities such a cooking, machine shops and medical facilities. The expected trajectory is that the Old Guard recruits survivors to act as settlers, and once they have a sufficient number and have located a strategic location for a settlement, they establish a settlement there and decommission a ship to act as the core of the settlement. In parallel with this decommissioning effort, the Old Guard would prioritize establishing a provisional and then permanent government to maintain their legitimacy.

One possible ongoing campaign for the Old Guard might be clearing and forming a permanent zombie-free zone on Nantucket, then launching a similar campaign to attempt to retake Martha’s Vineyard. Player/mercenary involvement in the Martha’s Vineyard campaign would be an option.

Steady State: Eventually the majority of the fleet is decommissioned as the cores of new settlements scattered across the eastern seaboard. A remaining skeleton fleet, operating with skeleton crews might continue to patrol the Atlantic coast to provide support to these settlements. The faction at this point is transitioned into expanding their control and solidifying their holdings. Settlements built around a decommissioned ship have a massive head start compared to most settlements, but at the same time Old Guard settlers would be the least equipped among the factions to adapt to the new realities of founding an inshore settlement.

Tacoma Commune

“An outpost started by the Free Merchants to provide a source of food and raw materials.”

Description: The Free Merchants send their idle hands to work at the Tacoma Commune. Hard work as a subsistence farmer at the Commune is unpleasant, but it’s better than starving to death at the Evac Center, and Commune workers get first dibs on any food produced.

Over time, the interests of the Commune and Merchants are going to diverge, and the Commune workers are going to be less and less interested in paying taxes to the Free Merchant.

Structure: The foreman and crop overseer run the joint.

Goals: Build a small village at a ranch.

Size: 2 people initially but increases over time.

Attitudes: A colony of the Free Merchants that initially takes their attitudes.

Bases: Controls a ranch.

Trade/Economics: Uses Free Merchant scrip for commerce, with substantial black market trading in cut logs and healthcare services.

Missions (fairly complete): acquire supplies necessary to expand the commune, help build the commune, defend caravans to the evac center.

Proposed Factions

These are factions that are not yet in the game.

Major Factions

These are proposed factions with a scope similar to the Free Merchants or Tacoma Commune: large groups that will have substantial influence in the CDDA world.

Micro Factions

These are proposed factions that are tiny and will have little influence on the CDDA world, though they may have many missions or dialogues and the player may find them very intriguing.

Free Merchant Beggars

Five beggars living in or near the Free Merchants evac center, but not considered part of the Free Merchants.

Fort Evac

A quintet of survivors at an Evac Shelter, who fortify it. One of the survivors eventually disappears and another breaks off to become the arsonist at the Evac Center.

Camp Wild

Camp Wild will eventually be a trio of NPCs building their own faction camp in a reasonably suitable spot.

Extradimensional Forces

There are three key extradimensional factions currently implemented in Cataclysm.

The Blob, known to XEDRA scientists as XE037, is the entity responsible for the Cataclysm itself, and for zombification. It was discovered before the Cataclysm and was the key focus of XEDRA research leading up to the zombie outbreak.

Triffids are a species of intelligent plants that crossed into our world during the initial portal storms of the Cataclysm. They perceive humans as meat, and little else, but are probably the most human-like of all the extradimensional beings.

Mycus is a dispersed intelligence whose primary interest is growing and encompassing all things. It is strongly opposed to the Blob, but shares a lot of similarities with it.

The Netherum is a disorganized collection of demonic creatures. They do not appear to have a central underlying motivation, but are generally hostile or at least not particularly friendly.

Further extradimensional factions not only could exist, but probably should.

The Mycus

The Mycus loves you, and it just wants to be together forever.

If the Blob is a mugger in an alley that hits you over the head and takes your stuff, the Mycus is a creepy guy with a candy van that tries to tempt you over to it.

The Mycus’ goals are actually rather similar to the Blob. It wants our world and our people to become part of it. Its mind, however, seems to be more suited to understanding the individual, at least somewhat. If it can’t make you part of it the easy way - by filling your body with spores and using you as soil - it will try to make you part of it another way. Have you tried this fruit? It’s delicious, and provides all the nutrients you need to live. Try another, go ahead. We can make all you need. Don’t you want to come with us now?

Didn’t the fruit work? Hm. Perhaps we’ll need to try something else. I know we can find a way to be together.

For Survivors
It’s dangerous and tempting to think the Mycus can be reasoned with. As interactions with NPCs become increasingly complicated it is likely the Mycus can play a big role there. It’s the sort of intelligence that would send a sleeper agent into your base and try to put spores into the water. It’s the sort of entity that is really tempting to build cults around. After all, if you join us, we will provide for you.

Philosophically speaking… is joining the Mycus all that bad? I guess it depends how much you value individuality. One could see the Blob and the Mycus representing opposite ends of a transhuman spectrum. The Blob is cold and uncaring, but offers freedom. You can use it to become anything you can imagine. The Mycus will help you, but you must give yourself up to it completely.

Also you must like mushrooms a lot.

“The Blob”, XE-037

See the Background document for full details.

General Description:
The Blob is a dispersed intelligence vastly greater than anything conceivable to a human mind. To it, we are as significant as individual cells of a body. Human researchers obtained samples of the Blob. While XEDRA experimented on it, it passively observed them and then decided Earth was a worthwhile location to add to its dispersed body. So, with less effort than a human takes to scratch its ear, the Blob rolled into our world and made us part of it.

Inscrutable: The Blob, as a concept in writing, should be thought of less like an antagonist or a character and more like a set of rules and a force of nature. None of the direct interacting organisms in the game world are even particularly aware of its existence. Those few that are aware that XE-037 exists do not realize that it is a vast interdimensional organism. This information might never be directly revealed in game.

What does it want?
The Blob is vast. It cannot be communicated with nor reasoned with. The most we could possibly manage would be to annoy it enough that it would reach out and slap us, and that would be that. Far preferable would be for us to convince it to leave us alone - which really isn’t that hard, since it doesn’t really care about the human survivors whatsoever. It is in many ways analogous to a Lovecraftian elder god, but one that has already woken up, devastated the world, and moved on to other things.

Quest options
With the Blob itself, there really aren’t any. You can’t convince Azathoth to go away and leave us alone, it’s not a thing. Zombies cannot be cured; their brains are mush, they are dead. Perhaps sufficient purifier could clear your own XE-037 infestation for a while, but unless you plan to drink treated water the rest of your life, it’s going to come back, and what have you really accomplished? Survivors’ best hope is to get the Blob to leave them alone, which is mostly wants to do anyway.

Ubiquitous, reanimatory, mutagenic
See Effects of Blob Infection for more information.

The groundwater is infected with XE-037. Every creature on Earth is contaminated. In larger mammals, this contamination allows XE-037 to reanimate us after we die, becoming zombies. In insects, it causes mutation to larger forms.

The XE-037 contaminating all living things is not the Blob, any more than a transistor is a computer processor. This basic Blob biomatter can be coerced into causing mutations in infected targets (i.e. anyone), using mutagen.

The Exodii

See the Technology document for more details on how Exodii technology works, both practically and (non-canonically) some of the theory ideas for how it could function.

Other Alien Forces


The mi-go have been known to humans, and vice versa, for some time. At least a few specimens have been captured from crashed ships. See the Background document for some details.

General Description
Mi-go are extraterrestrial, and possibly extradimensional, aliens. They have a few different subtypes, which may represent castes or subspecies or simply professions. All of them parrot speech, and seem to be able to parrot shared experiences, but this is not completely universal. It is assumed they either have a hive mind, or access to some sort of shared network consciousness.

Goals on Cataclysmic Earth
Before the Cataclysm, mi-go occasionally swung by Earth to observe its inhabitants. Now, with our governments fallen and our planet on the precipice of complete extinction, they are here to salvage what they can of use. To them, this means capturing as much of our remaining biodiversity in the form of slaves and samples to be shipped off-world for study. Some samples will be disassembled for easy transport, but some live specimens will be sent back whole.

Mi-go Culture, Technology, and Opinions on Humans
Most of this should remain strictly behind the scenes. Mi-go have an advanced spacefaring and dimension crossing culture focused on rigidly engineered biotechnology. They consider technology that is constructed, rather than grown, to be something of a religious anathema and are strongly opposed to it. Despite this, the mi-go would not consider themselves overtly hostile to humanity as a whole; to them, most humans have been perfectly reasonable to the mi-go and vice versa. To the mi-go, cutting up a captured specimen to see how it works is the species equivalent of a cautious handshake, and they would take no offence. What would bother them heavily is a knowledge of how mi-go biology has been used to design compact bionic modules, but it is unlikely they have an intimate understanding of the specifics of this.

Mi-go technology is inscrutable to humans. The very principles of their devices are wholly alien and do not make any sense to us. It is likely they feel similarly about our stuff, if they even had a mind to study it - which they largely don’t, seeing our metal trinkets as disgusting garbage.

Mi-go do not seem to be susceptible to the effects of the blob, but this is more likely to be due to their ability to fine-tune their own biology than due to any inherent immunity.


Gameplay Table of Contents

The player can interact with the game world in a huge number of ways, if there’s something a survivor can do on their own in reality, they should be able to do it in the game. The game world is a huge uncaring machine, it doesn’t react to the player’s existence, it’s just passively hostile. Generally speaking the player advances in capabilities by acquiring better equipment, learning things, practicing skills, and gaining allies.


DDA fully embraces the sandbox concept of gaming. There are goals in DDA, and stories and missions, but the only universal goal is survival.

Short-term objectives include obtaining gear and supplies, learning things, crafting items, helping fellow survivors and exploring.

Medium-term objectives include securing supply sources, establishing a base camp or base vehicle, recruiting NPC allies, joining a faction and clearing an area of enemies.

Long-term objectives include deeply customizing your base camp and/or vehicle, securing a large surplus of supplies, founding a faction and/or making a faction self-sufficient and defeating large groups of enemies.

Game Stages and Timeline

Game Stages and Timeline Table of Contents


This is an approximation, and does not describe the expected timeline from a player perspective, but rather the expected design structure. In other words, it should not be hard-coded that a given feature is only available on a given day, but rather, game design should make access to that feature require a particular time investment making it unlikely to obtain earlier.

All these timelines are targets. Currently most of these features are available too early.

This assumes a start date on day 45 of spring, because personally I think that should become the canonical start.

Dev/balance notes:

One of the bottom lines of it is that there needs to be a ton more stuff to do and explore, rather than the main game objective being to level up in large leaps and bounds

This playstyle depending on longer frames of time and things taking realistic periods to be built/developed may depend more heavily on things being automated such as

  • fast travel options
  • schedule eat/drink/sleep/stoke fire options to allow players to skip a week or two of time
  • NPCs doing more of the long term crafting and projects in a more automated way.

This would allow the pace of the game to be slowed just a little, while the calendar ran faster.

“Lone Wolf” Play Element

Early game

Characterized by: Low to no transhuman/sci fi elements. Focus on food security and basic survival. Development of the skills and tools that change you from a “survivor” to a “Survivor”. Little major role for factions or large groups of NPCs except as a backdrop. Many wandering NPCs that may be hostile, but aren’t part of organized groups yet.

Terrified and Wet Phase

first couple days to at most first week.

Key events:

  • Find a basic safe shelter.
  • Find enough food to keep you sort of alive.
  • Find some clean water.
  • Make a safe fire.
  • Get a basic weapon and some good clothing.


  • The weather and elements
  • Hunger and thirst
  • Zombies are a mortal danger. A single zombie is manageable but risky. Multiple probably merit running away.
  • Dormant zombies are a major factor in cities, lying around as corpses unless disturbed.

Other Survivors/Factions:

  • At this stage of the game, they should be very common, and pose a huge threat if hostile.
  • Factions haven’t really formed strongly at this time. (The evacuees that will become the Free Merchants are forming the basis of their governance and have started writing notes on old money to make for fair division of resources.)


  • Travel is almost certainly on foot, within a day’s range of shelter if one has been secured.

Special notes:

  • Many elements of this phase, or the entire phase, might be skipped simply by starting with a particular profession or scenario.
New Scavenger Phase:

From mid-spring to end of spring, year 1

Key Events:

  • Get some armor and weaponry that deals better with zombies
  • Scavenge small settlements and their outskirts, mainly at night
  • Obtain a stockpile of food and a more serious water source, allowing you to spend a little while crafting or reading between exploration runs
  • Begin to stockpile food, books, and tools, but shouldn’t have enough food supplies to be able to spend much time reading or learning


  • Special zombies should start appearing and pose a significant threat at this point
  • Individual normal zombies can probably be managed pretty safely, with a bit of caution, but more than one or two is still a big threat.
  • Dormant zombies are still much more common than active ones (although there are many active ones)
  • Food security is not a day to day concern but is still an ever-looming issue.
  • The elements are not as big a problem at this point except when extreme.

Other Survivors/Factions:

  • May have one NPC follower, but they are not yet very loyal.
  • At this stage of the game, they should be very common, and pose a huge threat if hostile.
  • During this phase, factions begin to form as it becomes clear that the world has basically ended.
  • Find rumors of nearby factions (e.g. graffiti, radio signals, other survivors, computer in evac shelter)


  • While survivors may have a car or bike during this phase, range is still going to be restricted to “not far from home base” as they won’t have fuel reserves or ways to repair their vehicles
Wasteland Scavenger Phase

End of spring to mid-to-late summer, year 1

Key events:

  • Armour can reliably protect you from one or two zombies
  • Have at least one reliable but low-power long-range weapon, with enough ammo for regular combat, and/or a good, battle-ready melee weapon. Possibly a more powerful long-ranged weapon with rarer ammo for emergencies.
  • Food security is currently not an issue, starting to stockpile food for winter
  • Develop a pretty secure base, with little concern about small bands of zombies slipping in. Wandering hordes are a major threat (see below)
  • Almost certainly starting a farming operation around now
  • Have a vehicle, but it’s hard to repair and still pretty precious at this point
  • Able to make scavenging runs deeper into cities to get some good loot and tools, with a bit of free time to use books and things.
  • Possibly able to set up a basic electric power grid at the base.
  • Exploring Facilities is a very risky proposition at this time.


  • A lone zombie, or even two or three, pose little threat at this point unless backed up by specials. More than that and they run the risk of swarming and overwhelming you without careful tactics.
  • Evolutions of special zombies begin to appear and are a larger threat
  • Dormant zombies begin to wake up, forming the backbone of the first wandering hordes. The first necromancers and a few masters appear.

Other Survivors/Factions

  • May have a one or two followers, at least one of which is starting to build up some loyalty
  • Still a lot of other NPCs wandering dynamically around. Aside from bandits, they are probably becoming a little more cautiously interested in fellow survivors, rather than panicked and fearful.
  • Factions have now completely formed along their main lines and begin opening trade with each other.
  • Gain trust in other factions by running missions for them regularly


  • Likely have a vehicle, especially an easy to maintain one like a bicycle. Welders and repair tools are at a premium if available at all, so the vehicle is fairly precious. Range begins to extend to fill probably the entire starting overmap as the player is able to set up safe camps and things.
Preparation/Skilled Scavenger Phase

Mid-to-late summer to winter, year 1

Key Events:

  • Return of focus to food security as winter comes closer and survivor needs to work hard on stockpiling
  • Most other key resources are now well stocked - ammo, clothing, armor. Survivor has likely managed to make some deep forays into a few towns, loot a mansion or the upper levels of a Lab.
  • Although the player isn’t equipped to install CBMs or develop higher level mutagens they probably have access to the components now, and can start projects to get them on the go over the winter. Likewise for fancier gear and equipment that isn’t available readily from raids.
  • Decreasing focus on wide ranging travel in favor of developing base defenses
  • May at this point have achieved welding tools
  • Probably has electricity and a secure water supply at home base.


  • Small groups of zombies are pretty easily handled. Evolved zombies may pose a threat.
  • Wandering hordes are becoming a big risk. Base defense from them becomes important, especially with food stockpile protection being important. This serves to keep the player a bit more grounded at home as well, where running into a horde is more manageable.
  • More dormant zombies coming alive, but probably at least half are still dormant (gonna need cannon fodder next spring)

Other Survivors/Factions:

  • Have a small group of followers of varying levels of loyalty, some of whom can be left safely at the base to protect it and work on farming/crafting
  • Begin developing a relationship with some of the major factions esp. by selling off extra scavenged stuff now that you probably have a surplus of some things
  • Reach the point where some faction missions have run far enough to earn you enmity of opposing factions. May have to start choosing loyalties.


  • Possibly able to keep a fancier vehicle running now, making range quite a bit longer, but a higher risk associated if you have a stationary base due to wandering.
First Winter

Key Events:

  • Traveling outside becomes onerous (slow travel through snow), cold, and dangerous (zombies and other threats not visible under snow)
  • Encourage player to stay inside, building up the base, studying, and crafting


  • Wandering hordes travel less, slowed by the snow. Masters might take their hordes into cities and forests to avoid it
  • Dormant zombies aren’t visible under the snow making towns even more dangerous.
  • The winter itself is a threat with minimal electricity and no snowplows

Other Survivors/Factions:

  • Survivors without factions at this point die in large numbers as hordes move into the towns they’ve holed up in. This is probably the biggest die-off of survivors since the cataclysm
  • Factions hunker down, trade routes close off. Brave players able to travel in the snow might find this a very effective time to get a huge amount of faction favor by doing important jobs, at very high risk.
  • Players who haven’t set up a safe enough base might choose to use their faction favor to hunker down with one of them.

Side note:

  • Features to automatically consume food and drink and sleep on schedule while engages in long crafting projects would be a good way to make the winter speed by and not feel tedious, while also keeping the “homestead winter” shut-in feeling.


Characterized by: Player beginning to adopt transhuman elements if desired. First serious raids to Facilities - labs, bunkers, military bases, and other ‘dungeons’ - become possible. Zombies “level up”, so that you’re facing not so much individual monsters as nemesis-level masters and their hordes. Other enemy factions (triffids, mycus, mi-go, others?) begin to expand as threats.

Side note: As this is a switch to a very different play style, it should be possible to start out in this phase with some scenarios.


Characterized by: Player has numerous transhuman elements and top-tier gear. A single player can probably take on even top-shelf zombies in large numbers, if they’re smart about it. If the player has a faction or a community of their own, protecting that group is more the challenge than trying to survive themselves as they’re basically a superhero. Earth becomes a battleground, with warring factions claiming most of the overmap.

Balance note: at no point should a player ever be able to simply wade into a horde of zombies without fear. Drive a tank, sure. Man a turret, perhaps. Walking into the crowd however should always be at least a last ditch fool’s errand. Superhero, not demigod.

Side note: This shouldn’t be something players can start in straight-away as the challenges of late game derive from things developed in the mid-game.

“Faction” Play Element

  • Starts in late Early phase or later
  • Develop and protect a community either from scratch or by joining an existing faction and rising through its ranks.
  • Focuses on building, protecting, recruiting, trading, research, and diplomacy.
  • End-game: Carve out a “safe” portion of the world, or abandon this world hoping to find another that you can survive in.


The world ended. You don’t know what caused it, but suddenly everywhere was being overrun with monsters of all kinds. Now only a tiny fraction of humanity is alive, the dead fill the cities, and worse things are stirring in the wilderness.

Civilization is gone, but maybe you can survive. Maybe you can find others.

Style & Structure

Storytelling in CDDA should be fragmented and emergent, to simulate the idea that nobody really knows what happened. What people know is what they experienced, which was random and chaotic. There were no news broadcasts informing survivors that a hostile interdimensional force had decided to conquer Earth; one day, the dead started walking, and that was sure weird; while we were all getting used to that, the world broke open and creatures from nightmares moved among us eating people and smashing stuff. It wasn’t much fun, and nobody’s quite sure how it happened.

Those with the best knowledge of what happened are dead. Some of them left notes. Those notes should be hard to get.

Information about what really went down might be made contradictory, because it’s unlikely anyone has a full and clear picture of it. Much of what is regurgitated as fact is supposition, theory, or sheer crazy ravings.

Also, everyone has PTSD.

Background Information

Spoiler alert. This section will contain many lore spoilers for elements that are meant to be mysterious or hard to learn in game.


There was an arms race to develop transhumans. In the process, the US government discovered alternate dimensions and obtained a sample called “XE-037”, a mysterious black goo that was able to reanimate the dead and cause miraculous targeted phenotype mutations. XE-037 turned out to be intelligent - vastly so - and escaped, contaminating the groundwater and causing an enormous zombie outbreak. As this spiraled out of control, Earth became the target of a multidimensional portal attack through which the Blob, the entity of which XE-037 is just a small part, took over our world. Simultaneously, forces from other dimensions entered opportunistically as our dimensional fabric was destabilized. This was the Cataclysm.

Things are a bit more stable now, but nobody is left alive to appreciate that.

For a detailed explanation of how the Cataclysm came to be, see the Background document.

Effects of Blob Infection

Every living thing on earth is infected by the blob. In humans, passive blob infection has a few effects. This has some serious ramifications for gameplay and storytelling.

Increased Healing Blob infection means everyone heals more quickly from basic soft tissue injuries. It doesn’t affect immune systems and doesn’t have as powerful an effect on broken bones. It also doesn’t allow regeneration… Not unless you die, first.

In-game this is an explanation for rapid player healing; note that this means that rapid healing is diegetic, ie. characters in the game world are conscious of the fact that they heal much faster than before, and may comment on it.

Mutation The Blob seems to somehow store a base state for the infected creature (purifier triggers it to revert to this state). That base state can be copied and imposed on the blob by crafting mutagen that has been exposed to a target organism. The blob also responds to radiation and certain other toxic challenges by sometimes causing random mutations.

Mutagens work in part by copying a particular creature’s phenotype onto the blob, then merging that phenotype with the person consuming the mutagen.

Cognition The blob has a potent, albeit often subtle, effect on human cognition.

In about one quarter of the population, changes are basically unnoticeable.

For about half the population, the blob causes an increase in risk-taking behaviour, ranging from mild unsafe practices all the way to people attacking hordes of zombies with a stick.

The remaining quarter see a heavy increase in aggressive, violent behaviour, often completely out of character. The worst of these, about 1/20 of the population, become “ferals”, a form of living zombie. These ferals actually contain a much higher concentration of blob, are not seen as hostile to zombies, and mutate naturally with time just as zombies do. Ferals still maintain a degree of human intelligence, depending on how severely affected they are… Some can remember tool use, for example. Ferals led to a great deal of confusion over whether the reports of the dead rising were true, as feral behavior is very similar to that of zombies.

“Blob psychosis” is an out of game term for the increased violence experienced by this quarter of the population. Nobody in game calls it that. Strictly speaking it’s not a psychosis, but that term seems to have stuck in our game discussions.

Blob psychosis after the Cataclysm

Over time, most affected people acclimate and return to normal. Some remain somewhat less risk-averse than before (eg players). Those that tended towards high violence also drift back towards normal cognition slowly, although their actions and the memory of them likely leave them changed permanently.

True ferals are permanently altered. Like all living humans, their numbers were severely thinned during the Cataclysm; the fact that they weren’t targeted by zombies is balanced by the fact that they didn’t make much effort to avoid confrontation with police and military forces.

Ferals Now The majority of feral humans are difficult to distinguish from zombies. They can grasp and use simple tools like clubs and melee weapons, and will avoid dangerous obstacles, open doors, and other very simple actions largely governed by motor memory, but that’s about it. These comprise around 1% of the zombie faction.

About a third of ferals remember more complex things. These ferals might use complex tools properly, and would understand for example how to use a gun, activate a Hack, or put on a kevlar vest. They lack forward thinking and executive reasoning, and would be unlikely to engage in complex tactics (they might know how to arm c4, but would not think to put it onto your base wall to blast a way in) but can nevertheless be extremely dangerous. These comprise around 0.3% of the zombie faction.

A very dangerous tenth or so of ferals maintain most of their human intelligence. They can use any tools they would have in life, can plan tactics, and can assess your weaknesses and use salvaged materiel to exploit them… Basically anything an NPC should be able to do. Likely they can talk as well, although probably it would be difficult for them to be too deceptive. These comprise about 1/1000 of the zombie faction. Over time these will probably evolve into a variant living form of zombie Masters and become another nemesis level villain for the late game. Feral Masters would be exceedingly rare, probably 1/10,000 or less, given the low odds of an intelligent feral living long enough to evolve.

Many of the Blob Lieutenants sent to earth were probably the equivalent to Feral Masters among their own species.