Awakened to an endless night, vampires hungered for the life they lost. Possessing sharp teeth and claws, they sated that hunger by drinking the blood of the living. Whether or not a vampire retained memories from their former life, their emotional attachments withered as once-pure feelings became twisted by undeath. Feelings of obsession, envy, jealousy, and paranoia were often stoked after transformation.
Most of a vampire's victims became Vampire Spawn, ravenous creatures with a vampire's hunger for blood, but under the control of the vampire that created them. If a true vampire allowed a spawn to draw blood from its own body, the spawn transformed into a true vampire no longer under its master's control; however, few vampires were willing to relinquish their control in this manner. Vampire spawn became free-willed when their creator died.
Every vampire remained bound to its coffin, crypt, or grave site, where it had to rest by day. If a vampire did not receive a formal burial, it would lay beneath a foot of earth at the place of its transition to undeath. A vampire could move its place of burial by transporting its coffin or a significant amount of grave dirt to another location. Some vampires, particularly those intelligent enough to become spellcasters, set up multiple resting places this way.
Vampires were extremely dangerous foes in combat, even when fighting seasoned adventurers. They possessed unnatural speed and strength, could climb as if they were a Spider, and were able to transform themselves into a cloud of mist or a Swarm of Bats. They naturally resisted nonmagical harm that came their way, and actively regenerated when not exposed to sunlight or running water. Additionally, they could magically charm humanoids into trusting them with a glance, forcing them to submit to their will.
There were many rumors on how to fight off or kill vampires, but only some were true. Vampires abhorred sunlight, as its touch burned them, as did copious amounts of running water. A wooden stake to a vampire's heart would destroy it, if it was incapacitated in its resting place. Additionally, they never cast shadows or reflections, so any vampire wishing to move unnoticed among the living kept to the darkness and far from reflective surfaces.