Death Save, bonus content!
The impetus to write this came from listening to Taulbee and Spike talk about Death Save SupNerds Episode 23
Elf reproduction is bound exclusively to magic rather than biology. To conceive, elves must undergo a ceremony in which the spirit of the newborn is bound to the elves well before conception. Such ceremonies are complex and require rare components. Complicating these matters, the intensity of the ritual ensures that elves may only conceive of a single child in their lifetime. The decision to procreate is not undertaken lightly. As such, elfs rarely undertake this ritual.
Elves, just as they are conceived, are born into the world through magical ritual. The ritual forms the new elven body out of whole cloth, constructing a new being to receive the spirit of the newborn. Elves are born fully grown but spend years fully adjusting to corporeal existence. Elves die, extenuating circumstances notwithstanding, when they choose. This too involves a complex ritual in which the elven spirit is released back from whence it came.
It is speculated that the spirit world from which elves hail is finite in its population. More than one elf has experienced visions of a past life, or lives. Their connection to the other lives varies in its intensity. Elven populations almost never grow. At best they are stable. The elven kingdom of Naristria has, for hundreds of years, relied on isolationism and magic to largely shield itself from the problems that come with this demographic issue.