Typecults, companies, guilds, orders, schools

A - F
Assassin Guilds
Criminal Organizations
Druid Guilds
G - M
Mage Guilds
N - S
Other Groups
Psionic Guilds
Science Groups
T - Z
Thieves Guilds

Guilds are formed to serve some interest. This interest could be collective bargaining, protection, extortion, criminal activities, research, and so on. Some guilds are restricted to certain races, sex, faith, class or other characteristics. The means of becoming a member of guild also varies, some you only have to pay a monthly due and/or fee, while in others you may have to be sponsored.

Many guilds will have affiliate guilds, or shadow guilds, which are cover organizations for their more criminal activities. These shadow guilds will often take the penalty for heinous and illegal activities which could result in their expulsion or sanctioning of the group from a city or region. The loss of a shadow guild or its sanctioning allows the true guild to remain intact and able to carry out its normal activities. In extreme cases, investigations may track down the source of the shadow guild's power and result in severe penalties and possible death to the leaders of the true guild.

Me? In charge? Oh no, I was given the title Guild Master, it is my employers who should take the blame, how was I to know what they were doing and that there were multiple levels of control, I'm just a marionette!

- Doc Chiidel, Guild Master of a shadow guild to the Alluvium Wardens - "Pleas to the Gilogoth Magistrate"

Companies are mainly formed to make money. They may act either for themselves or be a government entity. Agencies are generally termed as those in service to a government.