Kinds of Changlings

The practice of Fae folk nabbing hapless mortals is as old as Fae itself, which is to say, older than time.  But there are a lot of different kinds of changlings.  The most 'classic' example of someone from Fae stealing a human child and replacing it with a Fae to be raised as their own is the most widely known and also occurred but even then, there are different kinds of replacements.

Inner Fae: Sometimes the royals would hide a member of a royal house to be raised as their own among the common folk.  Before the Great Sealing, this happened all the time, and in most of the fairy tales where the royal was raised by common folk, that actually occurred on Terra, not in Inner Fae.  Inner Fae was fantastically dangerous, and most common folk had at least a little magic not the least of which, how to tell if someone had stolen their child and replaced it with a noble.  To be clear, most common folk before High King Fiddleback were more than happy to have a royal take one of their children or lie with their daughter (or son) since it was a chance at great wealth down the line.

Middle Fae: This is what most people think of as Fae.  These enchanted children never return while the fae eventually finds out what it is and makes its way to the other side of the veil.  Humans make great servants for Fae because they are so easily enchanted and controlled, and usually the combined contracts, treaties and inter tribal rivalries give even the lowest dew drop pixie rights that a human simply does not have.  At least a Terran that is, since some kinds of fae ascribe rights to the inhabitants of Inner Fae.

Outer Fae:  This strange and chaotic place is pure magic.  Humans taken here are often simply incapable of dealing with or understanding reality when they return to it.  God help any family that hosts a creature from Outer Fae.  Ever see the Children of the Corn? That's a  mild case at best.

It Never Happened: One of the cruelest tricks played by the Fae is simply to implant a suspicion that their own child has been replaced when no such substition ever occurred.  This is done very often to those who abuse guest right or are ungracious hosts.  It is particually reserved for those that call them satanic in some form or another.

One Baby For Another: Sometimes Fae just like to change children for other children.  This is a particular favorite of theirs with next door neighbors, where, as the child ages large, incredibly stupid males think that their women have been unfaithful.