From My "Cursed" storyline set in the D&D universe:

The Magical Kingdom of GELDORN,Long was it suspected the the very Magical Powers that gave its Armies such Battlefield superiority,were actually spawning the monsters that were Raiding & ravaging the land....After a Thorough investigation,it was the King's Proclaimation that All practioners of Magic Hereby are Sworn to Abide to an Oath of Celebacy or Surrender all Materials & Give up all Spellcraft Immediately on Pain of Death....
Wizard or Witch,all are not to use their Craft if they intend to bring forth Children....

As strictly as the King's policy was enforced, They are some cases that slipped beneath their notice....

This "Cursed" one is Talein Gath a 1/2 Human-Shadow Elf whose parents were adventurers,Abroad on a Long Campaign when the Edict came to be....he seemed a "normal" young man,until sometime around his 18th birthday,when the tattoo-like markings appeared on his limbs & seem to move of their own accord when subjected to magical energies.....Thrown into King's Dungeon to await his judgement,He met several others who were about to face punishment for being born(sound familiar?)...Luckily His mother was a Master Thief in her younger days & passed on to Him all she knew,which Helped immensely in their escape...
That & an uncanny ability to melt into walls and shadows....