Mages Guild, Tinkers Guild, Cobblers Guild, Prostitutes Guild, Scribes Guild, Architects Guild, Brewers Guild, Vintners Guild, Weavers Guild, Ratcatchers Guild, Furriers Guild, Cooks Guild, Astrologers Guild, Healers Guild, Tailors Guild, Minstrals Guild, Barristers Guild, and the Syffim Guild (later known as the Fighters Guild).
The Thieves Guild and the Dark Brotherhood, due to their illicit nature, were obviously not part of The Guilds Act. However, it can be surmised that The Guilds Act was the inspiration for the structuring of the modern day Thieves Guild, at least as it was during the Third Era.
The Guilds Act became official legislation in 2E 321. It should be noted that the Fighter's Guild was actually formed before then, as was the Mages Guild.
The Guilds Act had a partial effect in Skyrim, unlike the rest of Empire controlled areas. The Bards College was instituted in Solitude, however, a Fighters Guild and a Mages Guild was not put into place. This may have been because there was an already well established group situated for those respective guilds. The groups were The Companions and the College of Winterhold.
Of the guilds officially listed, only the following have appeared in the Elder Scrolls series:
- Fighters Guild (as the Syffim Guild) (every game except Skyrim)
- Mages Guild (every game except Skyrim)
- Bards College (Skyrim)
- Thieves Guild (every game)
- The Armorer's Guild is mentioned in Fool's Ebony, Book III, however, is not a part of this act.