Anyone who has knowingly passed through a Gateway of one of the Four Realms and survived have been Tainted. The most common Tainted have experienced either the Grave through a near death experience or the Slumber through lucid dreaming. Although, there are numerous ways to enter each of the Realms, know as Gateways, often Baronies seek to create permanent Bridges between them allowing them to physically cross between the Realms. Not all who stand at a Gateway have the will or the strength to step through. It is this that sets the Lucid apart from mortals. Baronies such as the Watchtower are known for their Baptisms, forcing followers into a Gateway testing their resolve.
Having traveled to one of the four Outer Realms the Lucid are those who have become Tainted but have not yet forced into one of the Baronies. Once a mortal becomes Lucid they become aware of others like themselves and can perceive the overlapping Realms within the Unbound World. The Lucid is Tainted with the essence of the First Realm they experience outside the Unbound World and can learn to draw on its power. Once Tainted the Lucid may enter the other Realms but they will never cause another bond like that of the First Realm.