Stone of Tymora

The Stone of Tymora was an artifact sacred to the goddess of good fortune.

It bound itself to the soul of a creature of its own choosing, usually someone who was already naturally lucky. When the stone was in close proximity to the one it had chosen, that mortal could perform feats of extraordinary luck, such as taking a leap off of a tall building in a city, only to hit every piece of laundry out to dry on the way down, and then conveniently to land on something reasonably soft, thereby turning a certainly lethal fall into a mildly painful bump. Unfortunately, the nature of luck was that where there was good luck, there must also be bad, so when it altered the luck of its wielder, somewhere another soul would experience an equal amount of bad luck.