In the early days of civilisation in Cardea, it became obvious to the people of the land that much was to be gained by sharing knowledge. Those of like mind banded together into small brotherhoods, sharing their wisdom. In time, as their groups grew in numbers, they evolved into the formal guilds we have today. A guild is a place where a person can find support and encouragement from likeminded people. Most guilds guard their secrets from outsiders and sometimes the only way to learn the secrets of a guild are to join that guild.
Once within a guild, in all but a few, you will find that you have gained a group of people who will see to your education and wellbeing; people who will protect you from unwelcome attention and will nurture any ability you might have.