Personality
Vampires are undead. I.e. they have no souls, BUT this does NOT mean that vampires do not have complex personalities. Keep in mind that your vampire should still be well developed.

Siring
One may not sire (create other vampires) without the approval of the Council of Vampires. If one does sire without permission (s)he will be punished, direly.

Blood Drinking
Vampires may kill (only with the other character's permission) the person whom they are drinking from or they may just drain the body almost completely. If vampires choose to drink from one another there can be serious repercussions, if vampires drink another of their kind's blood 5 times they will be bound to eachother for eternity. Though vampires are by nature not creatures that like to attatch themselves to another person some do, do this and most regret it.

Ghouls
Ghouls are humans who dink from a vampire regularly. These people gain magical powers (the most noticeable is that they stop aging) but are bound to the vampire as their servant.

The Secret
It is important for kindred to hide their true identities. If someone gives themselves away it will result in execution, this rule is the most important for it endangers all vampires.