Hey, welcome to my guide that's a tutorial on Plague Inc. I'm not adding pictures yet but if you want them feel free to ask. Here we'll be covering sections a little more in-depth than the ingame tutorial does. Prepare your reading glasses because here we're getting specific. I will go into detail about how I think the genes work and specifics.

Before you start ANY kind of game, you must pick a disease. I'll focus on the 7 main types of plagues and the others can be covered in other guides because they're more complicated than the default plague types.

Each plague has (a) specific defining trait(s) that change the way one would normally play. It also has unique abilities

Bacteria: Standard Plague. Abilities slightly increase effectiveness everywhere

Virus: Unlock after completing bacteria on normal (casual with Pity Mode turned on) Costs DNA to devolve and abilities increase mutation chance.

Fungus: Unlocked after completing Virus. Has a harder time getting on boats/planes, a country can even send out healthy planes/boats if it's fully infected. Abilities infect random undiscovered countries

Parasite: blah blah blah, you know how to unlock. Does not gain DNA from infection, higher starting severity, orange bubbles give more DNA. Abilities reduce severity and increase infectivity

Prion: Takes longer to make changes to core stats than other plagues. Abilities act like Genetic Hardening on a higher scale (we'll cover Genetic Hardening later)

Nano-Virus: Harder to cure, increased starting infectivity and effectiveness in countries (excluding humid, where it has a penalty), cure start immediately, cure-slowing things are free/reduced price. Abilities reduce effectiveness of cure by a lot and significantly increase infectivity for a short time (unique to one ability) before removing bonus and reducing infectivity and significantly increase cost of cure (also unique) for a period of time before wearing off and reducing cost slightly, break the cure. Good for speedrunning.

Bio-weapon: Gains lethality over time. Abilities reduce lethality, reset lethality bonus, reduce chance of lethality bonus occuring, win game if humanity is fully infected (max out dat lethality)

Transmissions are one of the main ways your plague will spread. Transmissions will increase infectivity and other minor stats as well.

Birds: Increase border-to-border transmission

Livestock: Better spread in rural countries (India, most of Africa, etc.)

Rodents: Better spread in urban countries (China, USA, etc.)

Insects: Better spread in hot countries (India, all of Africa, all of South america, etc.)

Blood: Better spread in poor countries (Most of Africa, Caribbean, etc.)

Air: Increase chance of getting on planes and better spread in arid countries (Saudi Arabia, Australia, most of Africa)

Water: Increase chance of getting on boats (yeah, ♥♥♥♥ you, greenland) and better spread in humid countries (Most of South America, India, etc.)

Extreme Zoonosis: Small chance that a country that is close to an island country but without land borders to not give a ♥♥♥♥ and spread the disease there

Extreme Hematophagy: See blood

Extreme Bioaerosol: Increase chance of getting on planes/boats and better spread in humid/arid countries (see Air and Water)

As you can see, make the most of your Transmissions to max out the spread of your disease!

Kill people with these...

Symptoms will increase infectivity, severity, and lethality. (but not all of them. most tier 4 and 3 symptoms do increase lethality (only exceptions are Skin Lesions (tier 3) and Insanity (tier 4)), so make sure you evolve these last.)

All of these are good (surprisingly), except for lethality early game.

"So why the hell is severity good?" you're asking?

Severity incrases the amount of DNA you'll get from bubbles. With low severity, you'll get a measly 1 DNA from popping a red bubble. With high severity, you can get five!

Severity will also make people panic more causing labs to be destroyed. This effectively slows down cure research.

Lethality is also important because you want to win, right?

Anyway, there are too many symptoms to count, so you'll have to explore them yourself. I guess this was more about talking about how awesome severity can be rather than about the symptoms. Sorry about that.

Abilities are probably one of the most useful things in the game. They're, like, godly. Worship abilities. They are your god and master.

Cold: Increase spread in cold countries (duh)

Heat: Also self-explanatory

Environmental Hardening (req. Heat 2 and Cold 2): Significantly increase effectiveness in both hot and cold countries

Drugs: Increase effectiveness in rich countries; essential!

Genetic Hardening: Slow down the cure. Req. Drugs 1

Genetic ReShuffle (req drugs 2 or genetic hardening 1): Slow down the cure by a bit, but does not have the effect Genetic Hardening does

Special Plague Abilities: See Your Plague section

So, (hopefully) you've won your first game! Congratulations! You are now an official person that knows how to Plague Inc: at least a little bit.

So you've probably gotten a pop-up that says:

The following gene type has been unlocked for use in the game:

<gene picture>
<gene name>

And you're probably thinking:
"wtf?"

Well, that's a good thing.
Genes are REQUIRED for pretty much every guide here. So grind them up. A lot.
There are 25 genes total (40 including special plague genes) each with its own category. You can only use one gene from each category.

Here are the following genes:

DNA GENES: Allow you to gain bonus DNA in one way or another

ATP Boost: 8 starting DNA
Cytochrome Surge: More DNA from orange bubbles
Metabolic Boost: More DNA from red bubbles
Catalytic Switch: Gain DNA from blue bubbles
Metabolic Hijack: If you're a lazy douche then this is for you; you don't have to pop red and orange bubbles, the game does it for you.

MUTATION GENES: Changes mutation in one way or another
Darwinist: Increase mutation chance
Creationist: Decrease mutation chance
Genetic Mimic: Slightly harder to cure
Base Oxidisation: Allow mutation of transmissions; slightly easier to cure
Base Hydrolysis: Allow mutation of abilities; slightly easier to cure

TRAVEL GENES: Spead better in one way or another
Teracyte: Better chance of crossing a land border
Aerocyte: Better chance of getting on a plane
Aquacyte: Better chance of getting on a boat
Suppression: Better chance of crossing a closed land border
Native Biome: Infectivity is higher in starting country

ENVIRONMENTAL GENES: Spread faster in one environment in one way or another
Xerophile: Spread faster in arid environments
Hydrophile: Spread faster in humid environments
Rurophile: Spread faster in rural environments
Ubrophile: Spread faster in ubran environments
Extremophile: Spread slightly faster everywhere

EVOLUTION GENES: Affect evolving or devolving in one way or another
Ionised Helix: +2 DNA from devolving
Translesion +: Costs to devolve don't increase
Sympto-stasis: Costs of symptoms don't increase; easier to cure
Patho-stasis: Costs of abilities don't increase; easier to cure
Trans-stasis: Costs of transmissions don't increase; easier to cure

NECROA GENES: Exclusive to Necroa Virus; replaces Evolution Genes
Autolytic Shift: Slightly reduce zombie decay everywhere
Cytopathic Boost: People killed by your disease have a better chance of becoming a zombie
ThermoNecro: Zombies decay slower in hot countries
Spliced Activation: Abilities cost half as much DNA to use
Dopamine Inhibitor: People killed by a zombie have a better chance of reanimating as a zombie

SIMIAN GENES: Exclusive to Simian Flu; replaces Mutation Genes
Viral Affinity: Increases infectivity for apes (not humans)
Call of the Wild: Slows death of apes caused by humans
Together Strong: Colony DNA +1
Leadership: 1/2 Active ability cost (no, it does not halve the cost of plague abilities. go cri now.)
Adrenal Surge: Increase Ape Lethality, but reduces deaths from attacks

ARTIFICIAL GENES: Exclusive to Simian Flu; replaces Mutation Genes (again)
Coristol Sensitivity: Reduces success of ape research (A.K.A. labs don't give as much research as normal)
Latent Catalyst: +DNA from destroying said labs (similar to CS, eh?)
Ion Deficit: +Devolve cost, +Cure requirement
Ion Surge: The above vice versa. -Devolve cost, -Cure requirement
ATP Overdose: +Devolve cost, +15 DNA at start allowing you to immediately evolve Simian Neuro-Genesis

Genes are great because although some have downsides, the upside is usually stronger. Thus, it is recommended to use genes to increase your chances of success.

Humanity is the thing you're trying to destroy. Humans will act different based on how the disease is evolved, and the more severe/lethal, the faster they will act and the harder they will work to cure you. Be aware that severity and lethality is still good, just don't go crazy. Once you have been discovered shortly after they will start to cure you and shut you out. If the cure is completed you will be eradicated and lose the game (cri). Countries will shut land borders, close ports and do all kinds of crazy ♥♥♥♥ to make sure that you won't wipe them out. Islands are the worst.

Literally.

There's no other way to get to one of those damned things unless you're lucky ("<disease name> spontaneously infects Greenland" ♥♥♥♥ YES WOOOOO) and infect them some other way. Otherwise it's not happening.

Top 3(4?) islands I HATE (in no particular order):

Greenland
Caribbean
Madagascar
Morocco (morocco is on this list because it's so damn hard to infect)

This is why infectivity is important; you can spread everywhere before humanity can lock you out!

This is the end of this random guide about this game.

I want feedback to improve future guides, so, if you didn't like it, click the thumbs down button at the top. If you DID like it, click the thumbs up button at the top. If you're not sure don't click any of those.

By the way, I am and evolving (see what i did there) Plague Inc. master...
On mobile, I have beaten Bacteria, Virus, Fungus, Parasite, and Nano-Virus on Mega-Brutal.
I have a strategy for Virus on mega-brutal, check it out in the popular section (it's probably still there right?)

Feel free to rate favorite and comment.

(wait this isnt a utub video why am i saying that wtf)

ok bye

P.S.: Also my longest guide! This took forever (not really.)