A Clan is essentially an extended bloodline of vampires who share similar powers and weaknesses. Those Clans available for play are Brujah, Gangrel, Malkavian, Nosferatu, Toreador, Tremere, and Ventrue. Caitiff are those without a Clan.
Every Clan has specific Clan-Disciplines, Clan-advantages and Clan-disadvantages that differentiate them from the other bloodlines. For details on these, please refer to the files about the individual clans.
Clan Theme
Several of the clans and bloodlines set forth by Vampire - The Masquerade from White Wolf frankly do not exist in the world of this Los Angeles. Others still do. Only seven are commonly understood to exist in Los Angeles: Brujah, Gangrel, Malkavians, Nosferatu, Toreador, Tremere, and Ventrue. Our theme here is focused upon them. In other words, excepting only the availability of Caitiff, no other Clan or Bloodline is available to player characters (so don't ask). What characters know of the existence of other Clans and Bloodlines will be limited to the +news lores files locked to their lore levels.
As to the clans in play in Los Angeles, each has a dominant theme, a 'tone' to its structure and history. These themes are particular facets of the overall themes of the game. Not every single character in a clan needs to reinforce the clan's theme, but all players should keep it in mind when creating characters. Each and every 'tone' will be (and should be) present, to one degree or another, in every character on the MUSH. Clan themes are not meant to encourage stereotyping, but to give guidelines as to what the "feel" of each consanguineous line is within the city of Los Angeles. These themes do not necessarily hold true outside the city.
Clans in Los Angeles
Although each clan has its own traditions, areas of influence in the city, and places of power, 'Clan' in Los Angeles traditionally mattered much less than in other cities of the world. Under the Treaty of La Ciegena, the Elders of the City tended to be more concerned with individual advancement, and alliances based on personality and history rather than blood. With the exception of the Tremere, no clan in Los Angeles was fully united under a single ruler.
However - with Emerson's Declaration of Independence and a total of 7 Clan Elders residing in the Ancient's Domain, the interests of the Elders in their Clan-members seems to have intensified. Unlike before the Clan Elders and their representatives have been given a considerable amount of authority over their Blood. The measure by which this power is actually used to mingle in the lives of their blood-relatives varies widely per Clan and individual.
The only clan actually demanding loyalty from its members is the Tremere. Other clans generally allow their members to live their lives as they see fit. It is quite common, often desired, for Ancillae and neonates to form coteries, informal pacts, and mutual admiration societies outside of clan. However, there may be times where a Clan (Elder) comes knocking, and the vampire needs to do a balancing act, weighing their own or liege's interests against those of their Blood.
Younger vampires may feel this pull much less often than those that who gained sufficient power to become useful to their old. Clan too, is a variable; More traditional and achievement-driven clans such as the Ventrue and the Toreador, may request some amount of contribution from any member, whereas the Brujah and the Gangrel seem to share few common goals, if any. A Ventrue working with a clan-defined enemy may find himself ostracized, whereas a Gangrel could swap sites and none of them would care. In most cases however, it is a trade off; You get some benefit in turn for your efforts and you're prone to see some consequence when you betray your blood.
As for demography and power-balance, it is nigh impossible to pinpoint the most powerful clan, for each has its own weaknesses and strengths; its own focus. A more elaborate description of each clan's interests and goals can be found in the individual clan-pages and lores (On-game: +news lores/<clan name>).
In the Heart of Los Angeles at least, there is no significant difference in Clan-representation on a level of Elders, simply because the Ancient seems to restrict the presence of Elders to one per Clan, and is even rumored to control the number of Ancillae residing in his city. Looking at sheer numbers or the amount of territory held by a clan, does not provide a clear picture either, for it fluctuates too quickly to provide a solid, unambiguous view.
One could argue that the Malkavians of Los Angeles, despite their ultimate insanity, are backed by the power of their Ancient Prince and his brood. But, if and how much the aloof Ancient would bolster the political status of his own clan, remains to be seen.
More can be said about the districts surrounding the City of Angeles. Although all Clans are represented, including a handful of Nephilim, the Encirclement holds a strong presence of the most traditional Camarilla Clans. Prominently amongst them are the Ventrue, but backed by a considerable delegation of Tremere and Toreador. Similarly the anarch border areas tend to be populated by the less Traditional bloodlines, such as Brujah, Gangrel and Nosferatu.
Census Command
The following command provides an overview of clan representation on the MUSH:
+census/clan | Lists percentage of vampire characters in each clan |