The majority of trade and industry back on the Homeworld is controlled by the various guilds which operate throughout the world. Most craftspeople will belong to a guild, both because of the protection they provide to their members - and because of the sanction they impose on nonmembers who dare to practice their craft.

Guilds very massively in size, from a few thousand members to a few million. There is some competition among them where interests are seen to overlap, but for the most part smaller guilds will make deals with larger ones for mutual economic benefit. The smaller guilds will tend to be more specialised; it is not uncommon for apprentices of larger guilds to re-apprentice in a smaller, more specialised one.

Being part of a guild comes with many benefits. Guildmembers have access to the wider stock of knowledge of the craft, and all of the connections of the guild itself. Guilds will also provide protection in case of sickness, and will ensure that any dependents are looked after in case of early death. They also provide members with a pension. However, it also comes with downsides. Members are constrained to follow the rules of the guild, which constrain what they can and cannot make, and for how much they can sell their services. They can also be expensive, as members are expected to pay a percentage of their income towards the maintenance of the guild.

Crafters' guild hierarchy typically follows these four levels:

• Apprentice: A student of the craft, apprentices are not paid but do have food and board provided, along with their tuition.
• Journeyist: A qualified craftsperson, entitled to earn a wage for their work but not to own a workshop. May spend a period of some years 'journeying' to perfect their craft in order to submit a masterpiece.
• Master: Entitled to work for themselves or own a workshop, masters have created a masterpiece at some point which shows them to excel in their chosen field of work.

In addition, most guilds will have a council of mastercrafters who make the important decisions for their guild. Some larger guilds may even have regional sub-councils. Their council is generally elected by members of the guild itself. Journeyists and masters may also occupy specific roles within the guild - for example, a librarian of the guild's archives, or the authority on a specific area of the craft.

Some of the notable guilds who have sent members on the Curiosity mission include:

• The Guild of Rockbreakers
• The Guild of Starfarers
• The Guild of Brewers and Distillers
• The Guild of Smiths
  • The Guild of Weaponsmiths
  • The Guilds of Platinum- Mercury- Silver- Steel- and Goldsmiths
• The Guild of Agriculturalists
• The Guild of Clothworkers
  • The Guild of Embroiderers
  • The Guild of Tailors
• The Guild of Homomechanicists