survival and transmittance mechanics:

• Humans will not be turned when bitten/'harvested' unless they consume- or their blood is intermingled with that of a vampire's
• Vampires cannot produce their own blood as living creatures can and thus must harvest it from external sources. Vampires and humans have a similar dynamic to animals and plants, as the latter is self-sufficient in a sense and the former must acquire a nutrient it lacks from it
• Vampires must ideally have in their body the same amount of blood as they would produce themselves as a human (typically around 8-12L)
• Blood is recycled regularly (though at a reduced rate) and must then be replaced by that of an animal or human (the latter is preferable)
• Lack of blood would not result in death, rather a general weakening of the afflicted vampire
  • Basically similar symptoms of blood loss as seen in humans such as confusion, lethargy and poor coordination
  • Additionally accompanied by aggression, psychosis, general increasing desperation to 'feed'

effects of vampirism:

• Vampires have a drastically lowered heart rate (typically around 4 to 8 BPM) which accounts for the 'no heartbeat' thing
• Due to having an extraordinarily low heart rate they can hold their breath underwater for a considerably long time (like, several hours)
• Food is unnecessary save for pure enjoyment; vampires tend to favor very pronounced flavors such as extreme spice or very sweet things, etc. Preferences differ from person to person
  • Digestion is an unnecessary process for survival, and can even be detrimental in some cases as the digestive system requires a lot of energy to operate
    • In some vampire circles, eating whole food is seen as a sort of luxury status symbol, as it implies having easy access to extra blood supply that would supply the energy needed to operate one's digestive system
    • Many vampires who enjoy the flavor of eating but lack the means to eat whole food in this manner will employ a sort of 'wine tasting' technique, taking shots of hot sauce, sugar packets, etc and then spitting it out
    • The garlic thing is fully a myth, most vamps love garlic
• Vampirism inhibits the ability to tan/produce melanin in excess, resulting in folks to appear paler & eyes to lighten in shade
  • People of color don't turn white obvi, they just sort of stay at their base... shade... ah, what the fuck am I saying. Y'know, like, when you're born?
  • While vamps don't fucking disintegrate in sunlight their lack of tanning ability combined with general photosensitivity causes profound burning at a significantly faster and more intense rate than humans
• Increased ocular photosensitivity and hearing sensitivity contribute to nightfaring habits, both as it's better for hunting but also to avoid the sensory overload that comes with hanging out during the day
• Vamps avoid crucifixes, holy water, silver (as it is considered a 'holy metal'), etc due to basically being godforsaken creatures in a literal sense
• Must be welcomed into spaces to enter, "come in we're open", welcome mats, etc provide the necessary recognition
• Reflection is not present in silver or otherwise consecrated surfaces, but can be seen in mirrors plated with other metals, on film, etc
• 'Superhuman' abilities of extreme(ish) speed and strength come from lacking the natural 'self-preservation' instinct of living humans. These abilities are basically on par with or a bit better than the average Florida man on bath salts
  • Sleep isn't necessary but they're able to if they want I guess
• Accelerated healing as all energy goes to maintaining the body rather than bodily processes like digestion, maintenance of body temperature, etc