Here is a list of strategies, tips and guides for the Mad Cow Disease scenario:

Strategy 1

Slow, subtle, complex strategy hidden inside your brain, scenario takes longer to react with your goals


Disclaimer: Success is not guaranteed, and I made this strategy all my myself. If there are anything in common, it's just a coincidence.

Caution: It's often VERY slow, so be VERY patient. Save/Load if necessary.

It has beaten Normal, but find other strategies if you are going for achievements/higher difficulty.

CRITICAL TIP: I find DNA VERY scarce in this scenario, so, spend it wisely. You don't have limited time, but you have limited DNA

Required Genes:


  1. Before you start, go to symptoms, and devolve all pre-evolved symptoms. You won't usually have the DNA required to remove them all and it's usually 4 removed before you ran out of DNA. Once you run out of DNA, proceed to next step.
  2. Choose any nation to start. I'd recommend China because it's a great vector. However, be careful. You don't have drug resistance, so it's slow.
  3. Keep an eye on the DNA bar and keep collecting bubbles to gain.
  4. Once you gain 2 DNA, immediately devolve a symptom. Repeat this until no symptoms are active.
  5. Evolve Frozen Storage Resilience, Hermetic Storage Resilience and Preservative Storage Resilience. You may be surprised at the very low infectivity, that's not what we want, but we are forced to.
  6. Now wait for the world to catch the disease. Expect it to take longer if you started in an unfavorable country. If things didn't went wrong, you can beat it in around 10 in-game years.
  7. Evolve Genetic Hardening 1 and 2. Do it before the humans discover the plague.
  8. Evolve Human-Cross Infection. Strangely, this doesn't seemed to boost infectivity, but it unlocks more symptoms that are more deadly to kill faster, the key to victory is to kill fast. Don't care about Plant Dissemination, it's a waste and you won't gain much.
  9. Once the world has been fully infected, you can start killing.
  10. You must get Total Organ Failure at all costs. If you are unsure about how to get this, use the cheat "Unlimited Strain" to determine in a trial or just go to this scenario's page to check out. Generally, it's the top-left corner of the symptoms page.
  11. Now keep track of the cure and evolve Genetic ReShuffle 1-2-3 if necessary. Or alternatively, get more deadly symptoms. Necrosis and Acute Encephalitis may help out. I recommend the second way because delaying the cure wastes DNA.
  12. Extermination must be fast. Otherwise, you will get furious because you're too slow. Remember that once around half the world being dead, further killings gain you a lot DNA that you can spend to speed up the massacre, at least before the cure beats you to it.
  13. Good luck on destroying the world! This is one of the hardest scenarios I've ever played.
  14. Don't dream of more than 1 biohazard, this is the best I can do.

Strategy 2

Difficulty: Normal

This strategy takes a long time and it only gets you 1 biohazard but it's something.


  • Metabolic Hijack
  • Creationist
  • Aquacyte
  • Rurophile
  • Translesion

Start location: India

1. Devolve all symptoms as soon as you can. You need 14 DNA points to do this, but you CAN'T save them up, you WILL get discovered. You have to evolve as soon as you get 2 DNA points. In my opinion this is the best order in which to devolve symptoms:  # Psychosis

  1. Confusion
  2. Headache
  3. Pins and Needles
  4. Dysphagia
  5. Paranoia

This order is important because this way you devolve first what has the most severity, and you decrease your chances of getting detected before you devolved everything. After devolving all symptoms you will get a notification saying your prion has been neutered

2. Wait. The only symptom that can evolve is Acute Encephalitis. It is very deadly so devolve it immediately. With Translesion it should only cost 2 DNA points to devolve every time.

3. Evolve Hermetic Storage Resilience (12), Frozen Storage Resilience (7), and Preservative Storage Resilience (6). I don't think it matters when you do it, but keep in mind that you need to leave enough DNA points to devolve Acute Encephalitis. And if you do it early it can speed up your game, of course.

4. As more of the world gets infected, some cold countries will take a long time to catch up. Evolve Cold 1 and Cold 2 to speed things up. Also evolve Human Cross-Infection. Again, make sure you still have enough DNA points to devolve Acute Encephalitis (or Confusion if you evolved Human Cross-Infection already).

5. When (almost) the whole world has been infected, evolve the following symptoms: (125 DNA points should be enough)

  1. Acute Encephalitis (41)
  2. Confusion
  3. Memory Loss
  4. Coughing
  5. Pulmonary Oedema
  6. Coma
  7. Total Organ Failure

You could also wait for Acute Encephalitis to mutate, because it saves a lot of DNA points. There is no guarantee it will mutate though. You could also reach Coma and Total Organ Failure through Inflammation and Systemic Infection. Those symptoms are deadlier, but you can't use them when scientists increase their understanding of Inflammation.

6. Sit back and relax, evolve Genetic Hardening and Genetic ReShuffle as needed.

Strategy 3

This strategy is adapted from the strategy made by Basost on Steam.

I'd consider this strategy the complete opposite of Strategies 1 and 2 since it's fast and aggressive.

To get 3 biohazards, you need 65,000 points. Essentially, it boils down to how many days it takes and how far the cure is completed. For example, if the cure is at 0%, you can take up to 410 days. If the cure is at 10%, you have only 400 days. 20% gives you 387 days, and 30% gives you 379 days.

Our goal here is to finish in under 400 days with the cure under 10%, giving you that lovely sense of victory.

CAUTION: If you have the Awareness Day Event before most countries are infected, you need to start over because the cure will advance too quickly.

Difficulty: Casual -- this automatically will help give you an island country.


  • ATP Boost
  • Aquacyte (Basost uses Native Biome, but I used this for a boost to get to the islands)
  • Sympto-Stasis
  • Genetic Mimic
  • Extremophile

Start in Saudi Arabia.

  • Evolve Ability : Human Cross-infection (15) as soon as you can. This takes ~17-21 days.
  • You have high severity so the disease will be noticed very quickly, and you'll likely receive notifications that research will be starting. Start evolving research-slowing symptoms.
    • Coughing (6) : Pulmonary Oedema (11) : Coma (8)
  • Evolve a few transmissions. Your infection rate will still be low afterwards.
    • Hermetic Storage Resilience (12) : Frozen Storage Resilience (7) : Preservative Storage Resilience (6)
  • Evolve more research-slowing symptoms:
    • Ataxia (3) : Blindness (13) : Paralysis (4)
  • You should be spreading to more countries now and generating a lot of DNA.
  • Evolve Abilities:
    • Cold Resistance 1 (8) : Cold Resistance 2 (14)
    • Heat Resistance 1 (12)
    • Genetic Hardening 1 (11) : Genetic Hardening 2 (30)
  • The cure is should be around 1%, and many countries are not yet infected. After evolving all of those abilities, though, you should be getting a lot more DNA pretty quickly.
  • Evolve Symptoms:
    • Hallucinations (7) : Insanity (10) : Cannibalism (22)
  • You want to get more symptoms that are focused on infectivity and lethality.
    • Pneumonia (6)
    • Systemic Infection (26) : Necrosis (26) : Abscesses (6) : Inflammation (8)
    • Mania (11)
  • At this point, if any of the island countries shut their borders, you've lost and need to start over.
  • I found it useful to evolve Fish (18) to get more ships carrying the disease.
  • Evolve some symptoms that give you a tiny boost of infectivity.
    • Delirium (4)
    • Seizures (6)
  • Pray for those few remaining islands. Getting a high score depends on if they are infected early. If their ports close, start over. You may, however, sometimes get spontaneous infections of Greenland.
  • Unleashing the most lethal symptoms:
    • Acute Encephalitis (41)
    • Total Organ Failure (29)
  • Evolve Genetic Reshuffles 1, 2, and 3 as you wait for the world to die.

My first try with this strategy gave me only two biohazards due to taking 487 days and 12% cure completion. However, it's totally possible to get both the cure under 10% and the number of days under 400.

Community content is available under CC-BY-SA unless otherwise noted.