[maximara]

Originally Posted by malloyd

That's largely wrong. All of these are caused by the same organism, the gram negative coccobacillus Yersinia pestis, just infecting different parts of your body. Cases can morph from one to the other as different tissues get infected (and in fact usually has to in order to kill you, the rare infection that stays confined to the lymph nodes, the classical bubonic form, is rarely fatal)

Still it does get at the difference between the spells indirectly. A spell designed to cure a "disease" with a particular set of symptoms - i.e. a subset of the 4th edition spell, would presumably only work on only one of them, but might work on similar diseases that happened to have the same symptoms (pneumonic plague for example has pretty much identical symptoms to a dozen other kinds of pneumonias). while one that was a subset of the 3rd edition version, that targeted a particular organism, would work on any of them, but not touch an identical appearing disease that actually [was] caused by heathens poisoning the wells.

An interesting book is Plagues and Peoples (1976) by William H. McNeill which goes into how diseases change over time.

What was called Leprosy in ancient times is not the disease we know by that name. Ancient leprosy caused scabs and crusts on the skin, leaft white patches (similar to vitiligo) on the skin, turned hair white, and caused bald spots.

Another weird disease is the "English Sweats" (1485 to 1551) — theories aobund as to what it really was. Some have suggested a variant of Scarlet Fever (which many of its symptoms resembled) while others suggest a hantavirus or some variant of anthrax.

I should mention that in very early versions of D&D (which heavily inspired Dungeon Fantasy) limited Cure Disease to "those (diseases) of a parasitic, bacterial, or viral nature" (PHB 1e pg 47)