Xipoli Continent Elven Law Volume 11. Everyone is born possessing an elf's egg. Participating in a duel is allowed for those older than 14, and the losers of duels are turned into women.
2. The victor become a "Holder", who holds both his own and the other's eggs. The loser becomes the "Devotee", and the Holder can issue commands to their Devotee with the elf's egg which must be obeyed.
3. The Holder may voluntarily return the elf's egg, turning the Devotee back into a man, 24 hours after the duel has concluded. (During the Devotee's pregnancy this cannot be done, and the Holder of the egg cannot duel others.)
4. Any "Devotee" will be granted a blessing from the Elves after their first loss (in the form of clothes and hairstyle to fit their new appearance).