Exceptionally lethal pathogen that kills everything it touches.

Plague Type:


Special Ability:

Gene Compression
Deactivated Modified Genes
Nucleic Acid Neutralization
Unlock Annihilate Gene


Complete Nano-Virus (Normal or higher) or $0.99USD

Release date:

May 23, 2012, Version 1.0

The Bio-Weapon is a genetically and biologically engineered and modified virus that was accidentally released from a laboratory. It is the final Standard Plague available in the game. It is quite similar to other diseases, primarily the virus standard plague type in physical appearance and in shape and size. However, unlike the previous plague types, the Bio-Weapon will grow progressively more lethal over the course of the game, making it more likely to kill off one's hosts before they are able to infect more people and causing quick detection. To win, the player must use the disease's special abilities to lower the lethality in order to avoid killing too many hosts too early. This quirk makes the Bio-Weapon ideal for speed run strategies. The interface of the Bio-Weapon also very strongly resembles an RNA Retrovirus.

By default, the Bio-Weapon has slightly higher infectivity than usual, and is better suited to rich countries than average.

Special AbilitiesEdit

Gradual LethalityEdit

Every in game day, the game will roll a random chance for the Bio-Weapon to increase lethality naturally. As the game progresses, the chance of lethality will increase exponentially. Nucleic Acid Neutralization will reset the exponential growth to zero, Gene Compression reduces lethality growth, Deactivate Modified Genes removes lethality.


For strategies, tips, and Q&A, please see Bio Weapon Strategy Guides.

Stages of Evolution Edit


Trivia Edit

  • Possible real-world Bio-Weapons include smallpox, Black Death, Ebola, or even rabbit fever. Anthrax is also a possibility.
  • If one assumes a symbiotic relationship is the most logical end of evolution, the Bio-Weapon is the disease type most prone to extinction because it kills its hosts quickly, sometimes before they can infect other people. This is due to the fact that with real-life diseases, there is a trade-off between infection spread and lethality.
  • Interestingly, its image is only a biohazard sign, directly opposed to other plagues, which have an image to explicitly introduce themselves. This is likely because other plague types (such as virus and bacteria) are able to become a bio-weapon, though the in-game Bio-weapon is more reminiscent of a type of virus.
Standard Plague Types