WorldGrower:Vampirism

Vampires are people infected with the disease Porphyric Hemophilia.
You can become a vampire by being bitten by one and contracting Porphyric Hemophilia.
When you have this disease for a long time, you will turn into a vampire.
Another way to become a vampire is to worship Dionysus.
If there are no other vampires in the world, Dionysus may bless the worshipper with vampirism.

When you become a vampire, you require blood to continue functioning.
It's possible to restore your blood level by biting people or drinking blood.
Once the blood level gets low, the vampire's energy gets drained.

As a vampire, you count as undead for all spell and item effects.
As an undead, you don't need to eat or drink, except for blood.