Olympia: The Age of Gods PBEM (Oct 4 2000)
Some skill categories have guilds which zealously protect the secrets to one or two important and powerful skills. To learn these skills, a noble must join the guild and study these skills in a guild hall (see Guild Halls).
A noble may be a member of only one guild, and once he joins a guild he
can never quit. To join a guild, a noble should either (1) enter an
appropriate guild hall, or (2) create a new guild hall using the
guild
command (see guild).
Note that whether a noble joins a guild by entering an existing guild hall or creating his own, he must first be ready to join the guild, i.e., he must have learned all the non-guild skills.