|There is more information available on this subject at Clan on the English Wikipedia.|
A clan is a group of people united by actual or perceived kinship and descent. Even if actual lineage patterns are unknown, clan members may nonetheless recognize a founding member or apical ancestor. The kinship-based bonds may be merely symbolic in nature, whereby the clan shares a stipulated common ancestor that is a symbol of the clan's unity. Humans, Forerunners, Sangheili, Kig-Yar, and Jiralhanae live or have lived in a clan-based lifestyle at some point in their species' history.
Sangheili clans are similar to those of the Highland Scots in the sense that those within a clan operate as a single family. The family name originates from their founder; for example, the Vadam clan was presumably founded by a Sangheili by that name. Clans are settled in states bearing the family name. They are run by a tribal chief known as a kaidon. The kaidon is supported by a council of Elders.
Kig-Yar clans ruled their homeworld before they were incorporated into the Covenant. These clans often competed for resources and raided each other's cities; they also held inter-clan competitions in major population centers. Even after the Covenant's dissolution, clans remain an element of Kig-Yar society, though they no longer hold as much influence as they once did. Kig-Yar clans often work in unity unless one clan has grievances with another.
- Main article: Pack
Jiralhanae clans are typically referred to as packs. A pack's chieftain is the group's absolute ruler. Succession among chieftains is realized by the successor killing his predecessor in honorable combat. Clans are the most prominent division in Jiralhanae society, however some clans united under similar interests to form larger "meta-clan" social divisions. These two social divisions became known as the Rh'tol and the Vheiloth skeins.