In faerie lore, what’s the difference between the Seelie and Unseelie Courts?
The difference is much like the difference between “lawful” and “unlawful” in, say, Dungeons and Dragons. The Seelie Court, while not necessarily “good” faeries, will help humans, give fair warning when a human accidentally causes offense (so that the human has a chance to make reparations), will repay a favor with a favor and generally don’t try to kill people for no reason. Members of the Unseelie Court, on the other hand, have a higher degree of mischief in mind, up to and including murder. The terms “Seelie” and “Unseelie” are Scottish in origin.