Psychological: Perhaps the root cause of vampirism in this world (such as a virus), inflicts an extreme form of OCD, hardwired into the vampire's brain.

I think you can approach it from three different avenues, depending on the tone of your setting: (enter virgin/elderly/child voice here:) Help! Scientific heeelp! I really would like to have a physical, improbable to alter reason for a vampire to grind their teeth and be unable to take an extra step into my residence. Then I thought of a selective force field, but those can be hacked/altered.

I was thinking about a psychological disability, but psychology is shifty and can be changed. Plausible explanation for lack of reflection in a mirror. In one short story, I recall that the vampire was unable to enter a shabby hovel before being invited, even when pushed into the entrance by a powerful ogre.īut I'm looking for a scientifically (can be soft science) explained vampire, such as in these neat questions and answers: the vampire's unholiness, or a magical physical prevention trick. This limitation is usually attributed to a measure of holiness (sanctity of a place of residence) vs.

If the good but foolish virgin/elderly/child says 'Do come in, what can possibly go wrong' - vamp goes in, blood comes out. They hang out in the doorway, looking all innocent and politely asking if they may come in. In a bunch of classical stories, vampires do have this limitation that prevents them from entering a decent folk's house without an express invitation. In my world there's the beginning of a vampire society, and some vampire resistance to sunlight, so I'm interested in other ways of hindering these otherwise super-powerful blood-suckers. There have been many terrific scientific explanations for some of the most interesting vampiric traits over the years, but this is one that I'm unable to find (Google, Stack Exchange). I'm looking for a scientific explanation as to why vampires would be incapable of entering a human's house uninvited.

Peter watts vampires