The human mage Lamal diSovel loved to entertain. Specifically, he loved entertaining children, delighting to see the surprised and enamored looks on their faces when he performed some sleight of hand or a minor magic trick. Traveling with a group of fellow performers and bards, Lamal got the pleasure of seeing the faces of hundreds of children light up, though it hurt the kindly wizard deeply to see the sad looks on those same faces when the traveling performers packed up and left town.
One day Lamal was in a magic shop looking for spell components when an adventurer came in to sell some minor magical trinkets he had found. Lamal was thinking about how much the children would love to play with these items when an idea hit him. He would create his own items to give to the children so they would not be so sad to see him go!
With this in mind, Lamal set himself to the task of studying up on the creation of magic items. He spent months with his nose in a book, reading and studying every moment that he wasn’t performing. After a few trial and error projects, he finally succeeded in creating the first of the hundreds of different types of magical trinkets he made for children during his traveling career, the black marble.
A black marble is a small ball of black glass that appears slightly warped, as though the glass it is made from was not shaped correctly. In truth, it was designed that way on purpose, since Lamal thought the funny shape would please children more than a perfect sphere. It detects as magical, but doesn't appear to have any obvious function. When it is placed on a slope however, it will roll upwards, defying any conception a person may have about physics or gravity.
When black marbles are created, they are usually crafted in batches of fifty. They are generally considered to be all but completely useless for adventurers and are mainly used as toys to entertain children. At best, they are a curious past-time to an adult, but children are almost always intrigued and entertained by them.