One thing I've always loved about vampire stories is that there are no hard rules. Vampires can be whatever the author wants them to be as long as they're internally consistent within the story. This makes them extremely versatile monsters that can be constantly re-invented and none of them are "wrong".
For example, sometimes all it takes to turn into a vampire is to be bitten by one. And sometimes you have to drink the vampire's blood to turn. Or, sometimes a vampire can just drain your energy without transferring any blood at all.
Of course, the rules can also get a bit ridiculous. Maybe the vampire is required to obsessively count grains of rice first. Or maybe they're required to hop around with their arms out (the chinese Jiangshi). Maybe they can turn into a wolf, a bat, or... fog.
So what's the most ridiculous rule or type of vampire you've come across?
(For the image on this post I wanted the most ridiculous picture of a Jiangshi I could find. I went with a shot from Robo Vampire which has a really fun RiffTrax. The only other Jiangshi I'm aware of is in the NES game Phantom Fighter... because I've never watched any of the Mr. Vampire movies)
Can't see themselves in a mirror but Dracula always had a perfect parting (from Karl Pilkington of course).
If they kill someone once a day to feed and turn them into a vampire in about a month everyone on Earth today would be a vampire, so the maths said they can't be real.
Wait a minute, jou just made me think about something. Vampires cabt see themselves in mirrors, but what about make up? Do they just see floating foundation? Whats the average makeup routine for vampires?
There is lots of story where vampires have mitigate or eliminate their affliction for day light, either with evolution, magic, science or something else. We may say they don't have a reflection as a general rule but there are some tricks.