The capacity of a Weyr varies from 300 to 600 dragons. However, during a Pass the dragonriders' duties leave little time for any other activity, so each Weyr has a large support staff that can number into the thousands.

Dragonriders
Living in weyrs (lower case w, or the individual cavern where a single dragon and his/her rider lives), usually in the cliff faces in Northern Weyrs.


Weyrlings
Young, immature dragons and their riders. Young dragons generally fly for the first time at about one Turn (year) and train with the Weyrling Wing until mature enough to join a Fighting Wing, usually between 1½ and 2 Turns. Weyrling dragonriders may not join a Wing until age 16, no matter how mature their dragon. Weyrling riders who have completed training but are not yet Turned 16 are often assigned messenger or sentry duties until they come of age. They do not have adult level rank/status until they have been accepted into a Fighting Wing.


Lower Caverns staff
Often, but not always, the Candidates who failed to Impress a dragon, or those who have run away from home to live in the more liberal, accepting atmosphere of the Weyr. Lower Cavern staff are often the grown children of dragonriders. This includes cooks, servers, cleaning staff for common areas, those who care for the beasts that will feed the dragons, and many others. Lower Caverns workers often satisfy the sexual needs of riders who have lost a mating flight. They are led and organized by a headwoman, who is usually ranked just under the weyrleaders in authority.


Weyrbrats
The children who are born in the Weyr are called (affectionately) Weyrbrats. Weyrbrats may be the children of Dragonriders, Lower Cavern staff or Crafters. It is the tradition in the Weyr that children are not raised by their natural parents, as dragonrider parents do not have time to raise a child while caring for a dragon. This community model also serves to reduce parental favoritism. Children are Fostered as soon as they are weaned from their mother's milk, and initially sent to the Weyr's creche. Once the child has grown to show distinct personality and talents, they are matched with a Fosterer (foster parent) who suits the child's temperament. Every male Weyrbrat has the right to become a Candidate and stand for Impression at age 12. Female Weyrbrats may become Candidates if there is a gold egg in the Hatching Grounds. By the end of the Ninth Pass, female Greenriders have become more common, so female Weyrbrats may be allowed to join the ranks of Candidates even if there is no gold egg in more progressive Weyrs.


Candidates
Young people who are given the opportunity to become a dragonrider. They are chosen through Search, where a sensitive dragon, usually a blue or green, seeks mentally sensitive boys and girls who are of the correct temperament to match minds with a dragon hatchling. Usually those searched are young males, aged 12–18, although older girls (aged 16–22) are sometimes searched if there is a gold egg available. With the addition of any Weyrbrat aged 12–18, the Searched are familiarized with the eggs and are present when the eggs hatch. The Hatchlings choose, or Impress a Candidate who suits his or her temperamental and/or other (still unknown) needs. The minimum age of the Candidates is decided by the Weyrleaders and may be changed according to the Weyr's needs. If there is a greater need for older more responsible riders, the age may be pushed back, if there is a lack of Candidates, the age may be lowered. The minimum age may also be changed depending on whether Pern is experiencing Fall or Pass. The youngest anyone has Impressed a dragon is aged 10 (F'nor), the oldest seems to be in their early twenties. There have been periods of time in Pern's history where females have been able to Impress and ride Green dragons. Whether or not female Candidates are allowed on the Hatching Grounds if there is no gold egg is unknown.


Craftsmen
Assigned to the Weyr by their Craft, Craftsmen serve the dragonriders and support staff as they would serve any Hold. The position is usually a high prestige assignment, and they are autonomous from Weyr structure. However some craftmen gain their position at a Weyr by being Searched and proficient in their craft discipline, at which point they are appointed by their Mastercrafter as the official representative.