With ever-changing appearances, changelings reside in many societies undetected. Each changeling can supernaturally adopt any face they like. For some changelings, a new face is only a disguise. For other changelings, a new face may reveal an aspect of their soul.

The first changelings in the multiverse appeared in the Feywild, and the wondrous, mutable essence of that plane lingers in changelings today—even in those changelings who have never set foot in the fey realm. Each changeling decides how to use their shape-shifting ability, channeling either the peril or the joy of the Feywild. Sometimes they adopt new forms for the sake of mischief or malice, and other times they don a new identity to right wrongs or delight the downtrodden.

In their true form, changelings appear faded, their features almost devoid of detail. It is rare to see a changeling in that form, for a typical changeling changes their shape the way others might change clothes. A casual shape—one created on the spur of the moment, with no depth or history—is called a mask. A mask can be used to express a mood or to serve a specific purpose and then might never be used again. However, many changelings develop identities that have more depth, crafting whole personas complete with histories and beliefs. A changeling adventurer might have personas for many situations, including negotiation, investigation, and combat.

Personas can be shared by multiple changelings; a community might be home to three healer changelings, with whoever is on duty adopting the persona of Andrea, the gentle physician. Personas can even be passed down through a family, allowing a younger changeling to take advantage of contacts established by the persona’s previous users.

The story goes that Doppelgangers were once Changlings, who were twisted and turned, into becoming Dopplegangers that hags used as agents to spy and gain knowledge.