Guilds were once major adventurer-run organisations which wielded great latitude over the classes of Achaea, often a time colloquially referred to as the Guild Era. For centuries, in fact, the term "Guild" was used interchangeably with "class", in which the Guild one belonged to determined one's class and vice versa. Centred around common skills and ideals, Guilds were led by a Guildmaster and his or her appointed secretaries. In the year 399 AF, however, Guilds became officially obsolete as these organisations underwent conversion to Houses.
The following are the former Guilds of Achaea and their respective classes, listed in order of their conversion to Houses: