Clans are, as the name of the game suggests, a major part of Clash of Clans. You can easily go through the game never joining one, but once you have repaired the Clan Castle
for 40,000 Gold
, this option opens up and it is one that is worth exploring.
Once in a Clan, players combine their Trophies
and fight against other Clans to get the most. These are collated and Clans are placed on a leaderboard based on the Clan's trophy total. Once in a Clan you also have a private chat, and are able to donate troops between each other.
Each Clan has three ranks of player within it: Leader, Co-Leader, Elder, and Member. The Leader, Co-Leader, and Elder have the ability to accept and decline Clan invites, while the Leader is also able to demote themselves to Elder and pick a new Clan boss. Many Clans have a certain number of Trophies
that you should have to be able to join. Once you reach that number, you will be able to send a join request.
To join a Clan, you can look it up and select the Join button (if it is set so that anyone can join). You can also send a request to join a particular Clan if their status is set to invite only. You could join a friend's Clan, or hang around on the global chat or game forums (like Supercheats!) looking for people recruiting Clan members.
See the Defenses section for more information on the Clan Castle