guild

A guild is an organization which provides a collective union for individuals of particular professions or expertise. Guilds function to help train individuals, to pass on knowledge, and to offer collective protection from exploitation.
Once an individual passes a test for entrance to a guild, they become an apprentice. An apprentice then becomes a craftsperson. From there, after a three-year journey (being termed as a journeyperson during this period), an individual is tasked with creating a masterpiece and thereby becoming a master. Guilds are typically led by one or more grandmasters, with the rules for progression from master to grandmaster being dictated by individual guilds.