Plague

File:IconPlague10x.png

The Plague is a power/trait that spreads throughout creatures and slowly kills them. It can be found under the "Other various powers" tab next to "Zombie Infection" and "Curse". The power is only accessible to premium users of Worldbox but it can still be introduced without premuim.

Description

The Plague is an infection that can be spread to any living creature (this excludes creatures like zombies, skeletons and demons) and across species. Once infected, a creature will begin to shake and periodically emit a purple particle. Every shake, a creature has a 7% chance of losing 10% of their max health. An infected individual will eventually die unless cured.

File:IconPopulation10x.pngGeneration and Transmission

Apart from being manually spread by the player, plague can also be generated by high densities of rats (more precisely, any unit with the "rat" trait; does not include rat kings). Specifically, for any given rat, if there are more than 10 rats within the same or neighboring zones AND within a 10-tile radius, it has a 14% chance to attempt to spread to units within a 6 tile radius. If this attempt is successful, every unit within range has an 50% independent chance to obtain the plague trait. Rats and rat kings are immune to the plague trait. Rats can naturally spawn in abandoned buildings and the wasteland biome.

Plague can be spread to creatures who are nearby. Whenever the plague trait effect is triggered, it has a 5% chance to attempt to spread to units within a 6 tile radius. If this attempt is successful, every unit within range has an 50% independent chance to obtain the plague trait. Plague is a dangerous tool as it can spread across most of the world quite rapidly. Even if separated by water, populations can contract the plague via flying creatures or boats.

You can see the spread of the plague by enabling the "ShowPlagueInfection" in the debug menu. It highlights zones different shades of purple to show varying densities of creatures with the plague.

File:IconPlagueDoctor scaled 10x.pngCuring and Immunity

The plague can be cured via the File:IconDivineLight10x.pngdivine light power, by manually removing the Plague trait via the File:IconDivineScar10x.pngtrait editor, or File:IconPlagueDoctor scaled 10x.pngplague doctors. However, these do not prevent reinfection. If the cured person is in close proximity to other infected, reinfection will occur nearly immediately. You can File:IconRainGamma10x.pngtrait rain immunity or immortality traits to prevent reinfection.

The "plague" trait has several opposite traits including File:IconImmune10x.pngimmune, File:IconImmortal10x.pngimmortal, File:IconRat10x.pngrat, File:IconRatKing10x.pngrat king, and File:IconBoat10x.pngboat; units with these traits are immune to the plague. Civilized units can randomly obtain the "immune" or "immortal" trait at birth which prevents infection; as these people survive and those without the trait die, populations can eventually have enough immune people to survive the plague but because of these traits low inheritance chances (10 and 1%) it is more likely to see the plague remain stable and never disappear.

The eventual outcome of a plague varies based on population size and density. Sometimes populations will die out before the immune trait appears; other times the population initially declines but later stabilizes due to drop in population density and consequent reduction in plague transmission, eventually causing the plague to become endemic. Populations can still be vulnerable to the plague after surviving, since the immune trait is not usually inherited to offspring.

Trivia

• Added in version 0.4.141 right before the Covid-19 epidemic became mainstream (December 19, 2019)