Sickness ravages Jaern like it would any other world. This page is primarily intended as a GM’s tool to create threatening and compelling diseases for their campaigns, and also features a list of common diseases that may strike both player characters and actors.

There are several dimensions by which diseases may be defined, and when writing a disease it is in the best interest of bookkeeping that you include information on all of them.

Where does your disease come from? A disease may fall into one or more of these taxons.

• Pathogenic: Caused and carried by miniscule creatures invisible to the naked eye. (These include bacteria, viruses, fungal spores, etc.) All Pathogenic diseases are communicable.
• Heritable: These are the result of the body betraying itself. Their origin lies in some malfunction of a bodily system, and the disease may manifest at birth or later in life. All Heritable diseases are non-communicable.
• Parasitic: These diseases may or may not appear similar to Pathogenic ones on the surface, but are the fault of larger, visible creatures that latch on to the body and drain its resources. Nearly all Parasitic diseases are communicable.
• Arcane: Usually created by malicious mages or alchemists, these illnesses are magical in origin. They often, but not always, attack the magical potential in their victims. Arcane diseases may or may not be communicable; note which it is when writing up an Arcane disease.

There are two main ways diseases may manifest, and the same disease may manifest in both ways in different patients.

• Acute: The disease strikes hard and fast. Once it is treated, it is over, but without treatment severe stages may be reached rapidly.
• Chronic: The disease is slow and steady, and is often something the afflicted must live with for long periods of time. While not as severe, chronic disease is often harder to treat.

There are a few different mechanisms for diseases to spread. Note that in most cases, more severe or even lethal diseases do not spread as efficiently. If a disease is non-communicable, it has no transmission method.

• Airborne: High efficiency. Spread through droplets or particles in the air, often coughed or sneezed out by infected persons.
• Filth: High efficiency. Spread via infected waste entering food or water supplies. Most dangerous in areas where proper hygiene is not kept.
• Surface Contact: Medium efficiency. Spread by touching a surface where infected particles sit. Diseases spread this way can stay dangerous for a long time on surfaces.
• Zoonotic: Medium efficiency. Spread by an animal intermediary. This may include bites from insects or larger animals, and the animal may or may not be affected by the disease itself.
• Direct Contact: Low efficiency. Spread by directly touching an infected person. There may or may not be wounds or sores where pathogens or parasites are in high concentration.
• Bloodborne: Low efficiency. Spread by infected blood entering the bloodstream of a healthy creature.
• Magical: Variable efficiency. Spread by various methods that are not physical in nature.

A disease is meaningless if it does nothing to those it infects. Following are some guidelines for the meat of your disease: the symptoms, and how these symptoms may progress over time.

Most diseases require checks against HEA to resist their effects, though an illness of Arcane origin or one that attacks the mind or magic might instead check against WIL or PWR. Some diseases may deal damage directly, disable the infected body, or apply long-lasting negative status effects. When a disease advances severity, the patient always gets a chance to remake the resist check and prevent advancement of the disease.

There are three major stages that most diseases go through. If a disease has both acute and chronic forms, two separate symptom blurbs for the effects may be warranted. Progression through the stages of severity varies from disease to disease, and is not always constant; ex. an illness may take a long time to become moderate, but then become severe very quickly after that. Acute diseases do not progress through the three stages of severity, as they are always fast and Severe.

• Mild: The patient has managed the illness well, or has just caught it. Mild forms of diseases are never lethal, and rarely disabling. Mild forms of disease may even be near asymptomatic.
• Moderate: The disease is noticeably worse. The moderate stage of illness is usually when most people begin to seek outside help and treatment. Usually, those in a moderate disease stage can still do everyday tasks, though they are noticeably sick.
• Severe: Depending on the disease, the patient may be bedridden, disabled, or dying. Those with a severe form of disease are unmistakably sick, and may be met with wariness by many communities.

Symptoms from stages stack; for example, if a patient is in the Severe stage, they are suffering from the symptoms of all three stages at once (if the symptoms of the three stages are not direct scales of each other).

There are many ways to treat diseases, including nonmagical to magical means. For example, a Treat Disease spell (Isis, Mending 4) can immediately cure Pathogenic, Heritable, and Parasitic diseases, and greatly assuage Arcane diseases.

The Science: Herbology and Medicine skills may also be used to treat diseases. Below are the standard checks to cure each stage of disease progression.

Casting Treat Disease or succeeding at a treatment skill check by 5 or more cures the disease completely. Otherwise, the disease severity reduces by one rank. Some diseases cannot be treated via standard means, or the standard checks may be harder; in these cases, treatment methods are specified case-by-case.