The will o’ the wisp began as a magical construct, but the Scourge turned something harmless into something dreadful … or at least unpleasant. The first will o’ the wisps served as portable lights. With one of these little creatures floating beside him, a magician never needed to carry a candle or torch and had his hands free to open doors, cast spells, and so on. To keep itself alive, the little creature drew magic from its surroundings, which it changed into sustenance. This conversion threw off the light the magician needed. Never able to stop once they had created a good thing, many magicians began to experiment with the wisps and created new varieties. One could remember simple instructions and guide people from one place to another. Others gave off sound or heat instead of light. Soon, too many varieties of wisps existed for any one person to remember.

During the Scourge, most of the wisps were left outside the kaers, where the Horrors slew and ate them. Some of the wisps, however, hid from the Horrors, and thus survived and bred. After five centuries of existence as wild creatures, the wisps have become just that. Most are utterly feral, and many were twisted by the Horrors as well. These latter specimens often dimly remember their ancient duties and perform them to the best of their insane abilities. A few—a very few—are sane and still remember their original purpose. Some of these, created as guides, can still lead people to their master’s home (or the remnants of it) and the treasures, if any, that lie within.

The most dangerous wisps are those meant to paralyze, harm, or even kill those who entered their master’s home without permission. The Horrors kept these wisps alive whenever they found them but drove them insane. These wisps now believe that their master’s home is all of Barsaive and attack as an intruder any Namegiver they come across. Almost as dangerous are the ones called magic twisters; these wisps can drastically change the effects of any spells cast within the area of their light. Sometimes they reduce the effects to almost nothing, other times they boost a spell’s power so that it flies out of the caster’s control.

What makes the wisp particularly hazardous to the traveler or adventurer is the similarity of their looks and the vast difference in what they can do. All wisps emit an unearthly green light, but here any resemblance between them ends. One can’t tell by looking which wisp is a still-sane guide, which a harmless light-giver, and which an insane defender of Barsaive. And because will o’ the wisps have bred and multiplied on their own for five centuries, many kinds may exist that their creators never envisioned. In short, any wisp may be able to do just about anything you can imagine—and perhaps a few things no one deemed possible.