Basics
Clans have existed since "RuneScape" began and allow players to group together based on some commonality. Players can join up if they have specific goals they want to achieve, such as training and honing skills with a group, attain a certain status such as completing every quest in the game or even if they simply want to travel around and get into fights with anything that crosses their paths. Others may simply team up based on shared interests.
Clan Camp
Players can find many of the Clans of "RuneScape" in an area called the Clan Camp, located outside of the city of Falador to the south. Players use the Camp to create Clans, join them, post messages and event invitations for other Clan members and even hold meetings and votes. Clans have the option to post messages and hold meetings both privately and publicly. The Camp has four important figures waiting around for players to perform certain actions. Players can visit the Clan Scribe to create a new clan, talk to the Captain of a Guard to receive a Clan Cloak to show their allegiance, meet the Sergeant-at-Arms to learn about Rated Clan Wars and Avalani to set up a Clan Citadel.
Creation
Clan creation requires at least five players willing to band together and serve as the Clan's founders. Additionally, one of these players must decide to be the Clan Leader and talk to the Scribe at Clan Camp to begin the setup process. The Leader receives a Charter, an item the leader uses to mark the four other players that will become founders. After a player creates the Clan, he can further customize the group's settings such as choosing a national affiliation, selecting the rules for who can join the group -- if anyone -- and even choosing the clan's visual motifs, such as colors and symbols.
Joining
Players who want to join an already existing Clan can travel to the Clan Camp and look for a Vexillum, a type of flag stand representing a specific group. Looking at a Vexillum will bring up information about the Clan, including an option to contact their Leader and see about joining up. Additionally, players can find a Clan's homepage on the RuneScape website and check out specifics on a Clan, including roster, goals and membership requirements, as some players set their Clans so a player must be a certain level to join. Others, however, have open memberships.
Rated Clan Wars
Clans can take part in Rated Clan Wars, where one Clan officially challenges another and, once the challenged leader accepts, they battle in the Arena. To take part, all willing members take an RCW badge from the Sergeant-at-Arms at the Clan Camp. These battles occur under a fixed set of rules to ensure fairness, and allow between 10 and 500 participants per clan. Depending on the rules, players can lose their items upon death, so there may be consequences to going to war.
Citadels
Clans can make their homes in floating castles called Citadels, which allow members to meet up privately or publicly in its meeting rooms and even have parties. To make them, five clan members must talk to Avalani at the Clan Camp to undergo the setup process, which allows players to customize the castle. Additionally, players can restrict access to the Citadel, allowing non-members to visit or make it specifically members only.