I try to apply science to fantasy when applicable. In this case, it's almost pseudoscience given the fictional nature of magic -- moving on...
Let's assume that positive energy (regardless of the source) rebuilds and restores damaged tissue. Negative energy would attack and distort healthy tissue.
Since positive energy basically regrows tissue, it's feasible that (if applied excessively) positive energy could create cancer. With the same logic, negative energy (if used sparingly) could kill any malignant growth and possibly the guilty tumors.
I think this would make for an excellent, albeit gritty, optional rule: when characters are healed beyond maximum HP, they risk cancerous growths. If the cancer is caught early, restoration and similar spells can remove the affected tissue.
Any thoughts on this? I've no idea about the mechanics at this point; it's just been on my mind for several days.
**I apologize if this hits close to home, that wasn't the intention.
Sounds like someone should read the series "Magic of Recluse" because I really think they will really like it -- a lot.
This is great, but you'd have to separate the cancer rules from the disease rules or Paladins could just cure cancer as fast as they caused it.
Well after thinking it over, this variant has a place in modern/post-apocalyptic/future settings, but not in standard fantasy. How would a healer recognize cancer without magic? The implications outweigh any benefit in such settings.
@Abraham spalding - grabbed a pdf, never heard of the series before.
@Viktyr Korimir - The plan is to reveal the cancer's presence through ability damage (type determined by cancer location), but to treat it as a condition (i.e. a negative level) and allow for restoration spells as cures (with heal/medicine checks).
@WhipShire - this is what inspired the idea to begin with, but I wanted an alternative to combustive healing. And I wanted negative energy to be useful in a way similar to leeches and maggot therapy.
I think you will like it a lot -- good writing style (even if some of the plot elements get recycled rather heavily) and the magic system is well thought out, and includes a *lot* of play with the sort of elements you are talking about here.