Necromancy: By some it is considered as nefarious black arts and by others a vault of opportunities, the very key to the secrets of life. A substantial part of the necromancer’s practice is devoted to undeath; a state in which one is neither alive nor dead. Unbeknownst to the general populace there are three ways in which undeath can provoked, and the curse of unlife bestowed upon the recipient.
This is a system for balancing magic based on two negative aspects: A) Magic creates “noise” that those sensitive to power will notice and B)Magic is channeled through rifts to other parts of reality OR other dimensions/planes/what have you and those rifts can get out of control…
Herbalist in the group mistakes one plant for another and mistakenly poisons the group. Not to death, but pretty darn ill with recurring symptoms until the cause and cure are realized. (Local people may be able to help rather easily. "You ate Dragon's Rot you fool, looks and smells just like mint except it has these small thistles on the root. Only grow in the Hornwood Forest, that must be where ya got them. Eat this and you will feel better in 4 hours."