Plagues can be gained by playing as The Necromancer class. First, the player must unlock the Biolab by reaching portal level 5. Once that is done, the Biolab will be ready for construction. Simply pay 200 mana, and the Biolab can be built. The player will then access plagues.

The Biolab serves as the hub where you can craft the perfect plague. There are a total of five tabs in the Biolab which can be used to modify and upgrade your plague. They are as follows:

Transmission- Choose how your plague is spread, and how effectively it can spread.

Lifespan- Modify how long the plague can last on various creatures, and objects.

Fatality- Choose how your plague kills its victims.

Symptoms- Choose what your plague does to it's host.

On Death- Choose a single effect that occurs on the death of infected.

Transmissions serve as a way to spread and infect the various villagers of the world. They are your main lifeblood of getting your plague from place to place, and victim to victim. All transmissions are as follows:

Airborne Rate- Allows your plague to spread when an infected villager Sings, Talks, or sneezes. A good fast way of spreading your plague. Pairs well with the sneezing symptom.

Consumption Rate- Automatically starts at low. Modifies how easily your plague can spread if a villager eats an infected food source. A death sentence for any villager with the gluttony trait.

Direct Contact Rate- Affects how often your plague will spread when villagers touch each other, and objects. Good for large, bustling villages. NOTE: Combat is not effected by this.

Combat Rate- Effects how often your plague is spread when infected fight other creatures. Great for warring factions, and villages that experience many fights.

To get your plague started, you will need to infect a single villager with the plague spell. This will cause them to get infected. The plague can also be spread with the Plagued Rats spell. This will spawn two plagues rats which will look to infect food sources when possible. Do be aware the rats are very, very weak, and will die in a few hits. Villagers will attack them on sight, so avoid spawning them too close. Oddly, villagers may try and arrest the rats and put them in a prison. If the world has ratmen, infecting ratmen is a wonderful way to spread the plague. Ratmen are immune to the negatives of a plague, so if they are accepted into a faction, they will spread it en mass.

Lifespan represents how long the plague lasts on an villagers, creatures, and objects. With a high lifespan, a village getting rid of the plague will be unlikely. Lifespan traits and infection times are as follows:

Objects: How long your plague can last on objects in the world. 24/48/72/96 hours
Elves: How long your plague lasts on elves. 48/96/144/192 hours
Humans: How long your plague lasts on humans. 48/96/144/192 hours
Monsters: How long your plague lasts on monsters and beasts. immune/24/72/120 hours
Undead: How long your plague lasts on undead monsters such as ghosts and zombies. Immune/24/72/120 hours

Be sure to pay attention to what you are infecting. This can allow you to make sure your plague is as hard as it can be to get rid of.

This is where the fun starts. Fatality represents several ways that your plague can kill its hosts. Pair these with your symptoms to turn a village into a open grave in days. You can only choose up to two of these, so choose the ones that work with your symptoms for the best chance at killing hosts.

Septic Shock: Give infected a slight chance to die whenever they become hungry or starving. This pairs well with the hunger pangs symptom, or the gluttony trait.

Heart Attack: Can cause infected to die when they become spent or drained. Pairs well with the lethargy symptom.

Stroke: Villagers can die when they get tire or exhausted. Also pairs well with the lethargy symptom.

Total Organ Failure: My personal favorite, Villagers have a very small chance to die when they do any action. This can be anything from picking up an item, to simply eating.

Pneumonia: Gives a villager a small chance to die when they move. Simple as that.

Be sure to select the fatalities that work best with your symptoms to ensure that no one survives your plague outbreak.

Symptoms represents what all your plague does to its hosts. These can be used to do a number of things. From farming Chaos Orbs, spreading faster, or killing villagers fast. Pick the symptoms that best suit your playstyle. Be aware you can only have five of these, so choose wisely, as you cannot undo your selections.

Paralysis- Renders a quarter of plague victims paralyzed. Any victims left paralyzed are permanently immobile, and will die in due time if no one takes care of them.

Vomiting- Makes infected vomit from time to time. This will cause them to loose some hunger. It also gives you a chaos orb when it happens. Good for farming chaos orbs.

Lethargy- Makes villagers tired after they wake up or sit down. Goes great with stroke.

Seizures- Leaves Villagers immobile for a moment. Also gives you a chaos orb. Good for farming.

Insomnia- Makes villagers sometimes fail to get good sleep, causing them to often be tired. Paired with lethargy and stroke, you can cause mass deaths.

Poison Clouds- Causes infected to occasionally let off poison clouds. The clouds leave poison for awhile and spread to objects. Can kill villagers if used right.

Monster Scent- Allows monsters to smell the villager causing them to be attacked from time to time. Can result in a villager being hunted down.

Sneezing- Makes a villager sneeze from time to time. This can spread it through airborne transmission. It also give you chaos orbs, which can be good for getting stronger.

Depression- Makes villagers often not do entertaining activities. Can be used to easily get cultists, as sad villagers are easier to brainwash.

Hunger Pangs- Villagers will occasionally loose hunger. Pairing this with Septic shock can cause villagers to drop dead fast.

Pairing symptoms and fatalities can easily result in wiping out villages, and farming chaos orbs quickly. Pair these well, and you will be like Grandfather Nurgle in no time.

These section is what can occur when villagers die. You can only get a single on one of these, so choose well.

Explosion- Makes a villager explode in a fiery explosion when they die, damaging everyone around them, and setting their surroundings on fire. This can be used to start a wild fire with ease.

Zombie- Makes dead villagers turn into zombies on death. Zombies spread the plague when they attack.

Chaos Generator- Makes villagers drop chaos orbs when they die from your plague. You can easily swim in chaos orbs with this.

Haunted Spirits- The Plagued spawn spirits when they die. These spirits apply various negative effects when they hit a villager.

With a lethal plague, you can make your plague kill even faster with these. Remember, you only get one, and it cannot be undone. Choose what you consider the most devasting.

Needless to say, the world does not respond well to you spreading plagues. If covid says anything, villagers will do their best to deal with your plague once they notice it is spreading. How they react however, depends on the traits of their settlement leader.

Quarantine- When infected are found, they are taken to the village hospice to keep them from spreading it further. If they lack one, they will construct it as soon as they can. This is more likely to happen if the leader has more merciful and forgiving traits. Destroying the hospice with destructive spells can be used to prevent quarantine.

Exile- When infected are found, they will be captured, restrained, put on the edge of town, and kicked from the faction turning them in to vagrants. This is more likely to happen with more authoritative leaders.

Execution- Infected will be captured, and executed to prevent the spread. This is happens with uncaring, evil, and sadistic leaders.

Nothing- On rare occasions, a leader may have no idea what to do. This results in you being able to spread your plague without a care.

Do be aware that the plague can occasionally cause interventions from Angel's should it keep killing. Keep your portal guarded well in case this happens.

This concludes my guide on how to infect, kill, and destroy the world with your plagues. If you have any suggestions, feel free to leave them below. I will get back to your when I can. Do be aware this whole guide is subject to change as Ruinarch updates. So until the game is finished, keep you biolabs filthy, and make sure your villagers suffer well. See you around!