Diseases are, well, diseases. They can be contracted in a number of ways, and they vary greatly in their symptoms and dangerousness. Diseases can be contagious to everything or just to specific races . Characters should be careful casting diseases they are able to catch. When cast as a spell, part of a trap, or, an ailment caught from a monster, the source of the infection creates the level of the disease. A 30th level cold is a LOT more severe than a level 2 cold.

Some diseases have a lifespan, and, if the monster or character that caught it survives naturally, they are immune to that disease forever, provided subsequent instances of the disease are equal or of a lower level than the source of the immunity. For example, you get a case of the flu cast by yourself at level 15. When you get over it, you're immune to any flu of level less than 16. When you become level 16 and cast the flu again, you are NOT immune. Spells such as “cure disease” or “restoration” will remove a disease, but will not grant immunity.

A diseases damage caused each round varies between 0 and the maximum listed resulting in the possibility of creating a MILD case of Ebola, which would NOT kill a monster, or a severe one capable of killing it. Some diseases get weaker over time.

Undead are NEVER affected by any disease, with one major exception: The Cause White Death disease (ie: Pneumonic Plague or Tuberculosis/TB), which is noted as “not currently available in the game” is actually available, but only to specific high level monsters, and never to players. No players, regardless of race, even if they are a follower of Devourers or are a Wraith, are immune to its effects, and cannot ever develop an immunity from surviving it without using cure disease or restoration.

The “Cause White Death” prayer is often used as a “template” spell when designing maps. For example, as a level/map designer, you may want a disease-like spell for your level 110 boss monster to use on any possible player: a matter-dissolving bacteria, for example, that periodically displays a message like “Mystic germs from another dimension start teleporting away pieces of your flesh”. For some neat examples of such a disease (spoiler), consider looking in to map-specific monsters, such as the Blood Golem or Advocate of Gorokh. So, best to always keep a keybinding to invoke restoration or apply rod of restoration; use_skill use magic item; apply rod of restoration; handy.

Any priest player who is not PATH_DENIED_WOUNDING
may learn and cast common diseases as: cold, flu, typhoid, anthrax, leprosy.