Vampires have a soul, but it's twisted and tainted.
The older the vampire is, the stronger they are.
Vampires can choose only 1 soulmate in their immortal lives.
Vampires don't have a heartbeat, don't need to eat or drink (except for blood).
Vampires need to drink blood regularly to refill their bodies. If they do not, they go dormant and lethargic.
Vampires can be killed by sunlight, decapitation and destruction of their heart (blessed wood works best).
Vampires can hear and smell better than any other creature, even werewolves.
Magic doesn't work on vampires in its natural form (as energy). They cannot be charmed, controlled or hurt by it. Only if the magic uses medium (something substantial like wood, metal, plastic or else) can they be hurt directly. Necromancy also doesn't work on them since, while their bodies are dead, their minds are not and they possess free will.
Vampire Hierarchy :
Hierarchy is absolute among vampires and it must be obeyed under penalty of death.
Only vampires older than 1500 years can be accepted in the Elder Council. The Elder Council is judge, jury and executioner for the older vampires (Masters handle lower ones). They are the ones that observe and make sure the Laws are followed.
Masters usually don't mingle with other vampires unless they have sired them (in which case they have responsibility for the offspring until the newly made vampire can control their bloodlust and protect their secret).
Nest Leaders are responsible for small groups of vampires, often watching over and educating recently turned offspring. They are assigned by Masters and if they do well, they can be raised to Masters, eventually.
Anyone who has been turned for more than 20 years is considered a vampire. For them to achieve autonomy and be allowed to venture into the world without the guidance of the Nest Leader, they must not have broken any of the Laws in the last 5 years of their immortal life.
Offspring are the recently sired vampires. They are usually a responsibility for their Maker for the first 20 years of their life, but in some cases - like the death of a Maker or accidental turning - they are entrusted to Nest Leaders.
Always follow the chain of command.
Do not expose yourself or others of your kind to the humans.
Do not bring too much attention to yourself.
Do not turn children into vampires.
Do not kill other vampires without the permission of the Elder Council.