A Thrall is an enslaved wraith of Stygia in Wraith: The Oblivion. Thralls are either slaves voluntarily, usually to pay off a debt, are forced into slavery through reaping, or have been sentenced to Thralldom by the Hierarchy for crimes against Stygia.
Once a wraith becomes a Thrall, it is nearly impossible to stop being one. Thralls have little if any rights in Stygia; even those who willingly sign a contract to become an indentured servant for a short period of time find the ending dates of the document ignored, and usually have no recourse to challenge their owners otherwise. Because of the constant abuse they endure, Thralls are prime candidates for Harrowings, takeover by their Shadows, and other unpleasant events.
Thralls always wear manacles of some form as a sign of their status, and some are also branded with the mark of their masters. They may only travel to the areas their masters allow them to.