The Rise of The Fallen
Collective name for the Elves, Eladrin, and Drow, and often including half elves born from these races. The Sidhe were once one people, but split into three following The March of The Nine. The Eladrin are descended from the Sidhe who fought against the Nightmare Prince, the Drow are descended from those who stood up to their kin and defended The Seven, and the Elves are descended from those who fled to The World rather than take a side. Each of the races is cursed in some small way as a result of these choices.
Eladrin and Drow suffer from the inability to dream. The Nightmare Prince created a race of eldritch horrors that could attack them through their nightmares and feasted on their misery. The members of these races learned how to Trance instead of sleep, but this has the side effect of leaving them vulnerable to The Madness.
The Elves, on the other hand, sleep and dream normally. However, they tied themselves to The World and forsook their fairy nature, which has left them less able to call upon the powerful magic once wielded by their ancestors. Very few elves can channel Arcane magic, and rely more on Primal, Divine, and Martial abilities. Few elves actually regard this state of affairs as a curse.