Plague

Plague was an arcane illusion spell that caused a person or creature to appear as if they were suffering from a horrid, disfiguring, and probably contagious, disease.

Effects
This powerful illusion mimicked a noxious disease, giving the victim the look, feel, and smell of a true plague-carrier that was obvious to any observer other than the victim. Anyone who saw, smelled, touched or otherwise perceived the individual affected by plague very likely believed them to be afflicted by some horrendous illness. As such it was not unusual for them to be shunned, as their existence and proximity posed a perceived threat to anyone nearby. While the illusory effects of the spell were clearly evident to anyone around the affected recipient, they themselves were completely unaware of any changes to their outward appearance.

When casting plague, the caster chose a specific disease the effects of the spell mimicked. If they chose an illness with which they were relatively familiar, there was a small chance it could be detected as an illusion upon close examination. If they chose a disease they had never encountered before, or one that was relatively new to Toril, the odds of the illusion's discovery were greatly increased.

The caster had to touch the intended target in order to cast this spell. If the victim did not resist, then the effects of this spell lasted for nearly five tendays, continuing longer depending on the skill and experience of the caster. They were not effected by the spell cure disease, but the illusion could be lifted by a sufficiently powerful dispel magic or negated by the caster any time they chose.

Components
In addition to verbal and somatic components, the casting of this spell required a small amount of charcoal, soot, or fungus, such as a black mold. A piece of human skin was also once required, but later versions neglected this.

Usage
While it may have been tempting for some mages to cast this spell upon a wealthy target and blackmail them to remove its effects, in Cormyr and Sembia in the mid-to-late 14 century DR, it was illegal for spellcasters to be rewarded for removing a spell that they had cast themselves.

History
This spell was uniquely found in Selvar's Ineffable Conjurations, Magicks, and Phantasms, the personal spellbook of the mage Selvar.

This spell was published in "Volo's Guide to All Things Magical" and became generally known to the magical community by 1358 DR.