I play 2 rivaling clans - the Trad and the Modern. The latter try to live like humans not feeding from sims.
Every 15 years each clan leader elect one member to join the battle, where two vampires go through a specific routine including spar(?), and the loser will be sacrificed to the Sun on the last day of the 15 year feast. It's a way for the leader to get rid of ant problem member, but also a way for me to kill of a vamp, as they live forever unless I help.
Count Vlad IV of Hollow is still leading the Traditional clan, and at the upcoming battle I believe he might turn in his eldest son, who refused to be faithful to the trad stuff, but rather wants to be a happy, colorful and responsible vampire. The leader of the Modern clan is Sophus Gorgel (aka Lord Wolfsbane), who originally grew up as a lord of the very well known House of Ross (they hold the dukedom of Rossie, which Hollow is a party of).
There's more, like residents paying house rent by offering plasma. But that's another story :)