Vampires
This was originally supposed to be for Vampire Week which was like a month ago. I wrote most of this then but never actually published it. Also, as you can see, I got way off course on the way to talking about vampires, so that only the last third actually has anything to do with vampires.
First, how does the afterlife work
These days most of my writing has a vague, implied setting, but one thing I have not defined is the afterlife. The afterlife is generally something of a problem. For instance, in Baldur's Gate 3, it has been pointed out that the Forgotten Realms having a well-defined afterlife has all sorts of weird implciations on characters' motivations, especially Hell being a literal, real place you can go look at. A lot of character motivations then seem incongruous with the world as presented. On the other hand, fantasy adventures tend to assume there is some form of existence after death, at least so you can like ask questions of the dead. Maybe even bring the dead back (though I want that to be fairly limited).
The solution I settled on is a kind of Sabriel situation (though not dangerous to the dead). There is a liminal space between life and death that the living can sometimes carefully delve into, and sometimes the dead can influence the world of the living, as ghosts. The spirits of the dead may hang around for a while, so long as they are concerned with the affairs of the living. But as their ties to the world of the living fade, most will pass on to whatever comes next. The liminal realm is a rather dreary shadow of the world of the living, liminal not in a cool or atmospheric way but in the way an airport is. As you travel deeper into the land of the dead, there is no returning at a certain point, either for the dead or for the trespassing living.
In some cultures, it's common to stay around for some time to help your descendents, though that help is only subtle and indirect. To encourage this, the living can give gifts to the dead, of the things they enjoyed in life. Where this is common, the land between life and death is more interesting, sometimes even having entire cities. These cities, however, have something of the atmosphere of Vegas - constructed entirely for the purpose of entertainment, as boredom is the only real problem; a strange facsimile of the real world; and surrounded by an endless wasteland on all sides.
In other cultures, you're expected to move on fairly quickly and leave life to the living, just as the living are expected to move through the various phases of life. Specific individuals do stick around for their own purposes, if they have unfinished business, and meddle in the world of the living as a ghost, but they most often would be motivated by spite, vengeance, jealousy, and so on.
Necromancy and the undead
I want necromancy to be feared and somewhat taboo, but I want to give a reason other than "because we said so".
The land of the dead is dangerous to the living, but not to the already dead - the monsters that lurk here need the life essence of the living to manifest in the real world, in the form of mortal blood, as well as a vessel to inhabit, most easily made from something that was once living. They also seem to desire mortal blood for its own sake. And so necromancers can use blood d (themselves or others') to bargain with these beings.
When given the opportunity to manifest in the physical realm, these beings can only have the nature of the blood they were fed in the ritual that awakens them. For instance, a being created from a rat has only the understanding of a rat, clever and able to fight but unable to talk or reason like a human. Some of the more desperate undead may be satisified with this bargain, and a skeleton animated by such a force may be useful to a necromancer. A necromancer can give some of their own blood to bring forth the intelligent undead for a short amount of time, but to create something truly powerful a human sacrifice is needed. As part of this bargain, these beings will usually be asked to swear a binding oath to obey the necromancer, but there are many ways to twist the words of those oaths.
Once in the land of the living, eventually they will exhaust their supply of blood and be forced to return. The only way to remain is by consuming more blood, and they prefer human blood, although without ritual assistance human blood does not make them more powerful. They can also conserve their energy indefinitely by waiting without moving, and so an ancient tomb undisturbed for centuries might contain skeletons that will come to life when disturbed.
Necromancy isn't strictly evil, but at best it's very dangerous. You might, for instance, empower the skeleton of an animal (to avoid grave robbing) with an animal sacrifice, which is no different from eating meat, really, but there's always a danger that it attacks someone. It's also unclear why the creatures of the Beyond are so desperate to enter the mortal world, but some believe that there is some vast and organized plan, and every undead incursion brings this plan closer to fruition.
You can also make other deals with the strange powers of the beyond, such as to bargain for knowledge or strange powers in exchange for a smaller offering of blood, but any power of the Beyond worth bargaining on is powerful enough that it may find a way to slip into the world of mortals - either by finding the dead body of an animal nearby that you overlooked, or possibly even by possessing your body.
Finally, vampires
I have a set of these sorts of templates to apply to Cairn characters. It could maybe be grafted onto other systems that are roll under?
I decided to double-subvert this by making vampires evil again - going specifically for the version where people become vampires after being dead instead of being turned.
This is also quite a bit more powerful than the other ones I made - this is probably only suitable for a solo game, or maybe as an antagonist. If you played them as a villain in your game, I think it should not be too obvious at first that they're a vampire - until they come back from the dead- and then the players need to figure out what to do so they don't have to keep fighting them.
You, once an ordinary human, have committed deeds in life so vile and unholy that upon death, your soul cannot pass on to wherever it is that souls go after death. Instead, 2d4 days later, you awake in your grave and, no longer needing to breathe, you claw your way to the surface.
You aren't "inherently" evil, in the sense that you still have free will, and you can turn your back on your previous misdeeds, though it becomes more challenging due to your vampiric nature. You can in theory stop drinking blood: you have the option to change your ways, you just are unlikely to do so given you ended up in this position to begin with. Nor are you likely to see any reward for doing so in this life, and the gates to the next one are permantly closed. Still, however, if you manage to avoid being destroyed through the centuries, that is a long time, and you may find yourself changing your ways.
- Boon: Whenever you die, an unholy power knits your body back together and come back to life in 3 days with 1d6 Strength. This costs an equivalent amount of Doom. If there are significant barriers to your body coming back together, this isn't possible - for instance, you have been beheaded with your head buried separately, a stake has been firmly driven into your heart, or your body has been significantly burnt or dismembered.
- Boon: If you drink the blood of a living human (or similar), you drain 1d6 from their WIL save and may restore the same number of points to any of your saves other than Doom. This is the only way you can heal. You otherwise do not need to eat, drink or breathe. If your victim reaches 0 WIL they act as if permanently charmed.
- Boon: You have three of the following spells. (1) Beast Form (must be a creature of the night), (2) Command, (3) Charm, (4) Control Weather, (5) Haste, (6) Hypnotize, (7) Manse, (8) Smoke Form, (9) Snuff
- Bane: You cannot abide the taste and smell of the food of mortals, and the stronger the smell the more it repels you. Garlic and spices in particular are anathema to you - they smell overwhelmingly vile.
- Bane: You cannot enter a consecrated place, or approach a holy symbol, unless permitted by the god of that place. Likewise, you cannot enter a home unless invited in.
- Your fate: When Doom reaches zero, you can no longer hide that you are a corpse, and you must either flee into the wilderness or face a certain second death.