One idea I was thinking about was vampirism as a disease.
This concept could be taken in different directions (for one: a disease isn't as controllable in its spread as deliberate passing of the curse of vampirism). You can also be more realistic with how vampirism works and its effects. Of course, this rules out vampires having cool superpowers, but having superhuman strength, agility, perception, etc. is good enough on its own.
As I recall, there’s a fair amount of fiction that treat vampirism as a pathogen or even an alien nanite, altho none of them are realistic because the whole thing violates physics (namely, no organism larger than a small bird or bat could survive exclusively on blood). It could be an explicitly magical disease. Folklore is full of vampire epidemics.
Take the Shadow Plague in
Plague, Inc. The shadow plague doesn’t turn the infected into vampires, altho they demonstrate symptoms reminiscent of vampirism. If you take the upgrade, then occasionally infectees will drop dead and reanimate as vampires with magical powers.
Of course, as far as video games go you have think about what makes for a good video game. Having to worry about controlling the spread sounds like it would be too much hassle unless the entire plot revolves around a vampirism epidemic. Limiting the superpowers to less flashy effects also seems like it wouldn't be much different from a game without vampires.
The relationship between a vampire and blood should be more to that of a drug addict needing another dose of his drug. In theory this is already taken into the account in some settings, but in practical terms (especially in games) the outcome is very lacking. This is true for any addiction in games, by the way.
I'm not sure it's even feasible to depict addiction struggles in a playable way. I did find a game book that treats
vampirism as an addiction (to the point where the vampires don't need blood to survive, so they can realistically go cold turkey), but that sounds like it would be really hard to make into a video game. Normally a video game treats the blood drinking as simply the way to refill the mana meter, so it's probably hard to do more complex stuff with that without making it frustrating.
Maybe treat it as a lightside/darkside deal (like that book explains)? The more you give into vampirism and feed the hunger, the more powers and other vampiric connections and temporal power you get, but at the same time you lose human connections and become less able to interact and overcome obstacles as a human being. E.g. initially you can persuade people with logic or seduction, but after becoming vampiric in that respect you can only rely on outright mind control.
Anyway, an idea I thought about has to do with vampiric factions (clans, bloodlines, covens, w/e). In
Bloodlines, you can play as one of seven "clans" (classes, basically, some with more or less exclusive options) and during the course of play you can pledge allegiance to one of several characters and their respective faction. Now, the writing can't decide whether clans are factions or not. While a vampire can choose who to align with, he cannot change his clan. Yet he is still free not align with any faction that claims to be that clan. It reminds me of modern identity politics and all those irrationalities.
I think a more elegant way to handle this is to firmly commit to one or the other. Either a vampire's bloodline is or isn't a political faction.
- MoonFall solves this by making it a choice on the part of the vampire-to-be to join a faction, and the higher ups in that faction have control over who gets to join. You can leave the faction, but can't found a new one without going through the presumably extremely laborious process of inventing a new ritual of vampirization.
- Bloodlust: Nemesis takes the approach of allowing you to build rapport with different clans to learn their signature powers. In this case, the choice of clan at character creation just makes it easier to learn some powers, but doesn't restrict you from learning others.
- Have explicitly separate axes of character creation/customization for a vampire's bloodline and a vampire's faction. For example, you might have different factions like the Hellfire Club and the Cult of the Dead who accept members of all bloodlines.
- Allow the character to choose their bloodline, rather than the player out-of-character. Maybe they start in a provisional position before joining a bloodline, like a mortal pledge or a juvenile vampire. Maybe a vampire can change their bloodline at some point, joining another or even creating their own.
That sort of thing. Any number of ways you could do it.
