As we have established in previous entries, reality is a weak and unstable force. So, how do our forms stay stable? How do humans keep themselves in the same shape day by day? Keep their houses and thoughts and the objects around them from twisting away and mutating into wild and terrifying shapes?
The answer is Culture. Culture is a physical force that exerts crushing pressure on you, like gravity. It constrains you and shapes you, forming your physical and mental form into a shape that pleases it. Culture is what keeps us from exploding into twisted masses of flesh when we pass through low-reality locations.
Culture soothes over everything and makes you unable to see the weird stuff at the edge of the world. You simply forget it as soon as you look away. Pedestrians step around the strings of drool from the beast looming over them and chatter about how rainy it is today. Loners and adventurers have built up sufficient counter-culture defense systems to be able to see things, but even they sometimes find the concepts slipping from their mind, like trying to hold onto fog. If they ever retire, they'll forget it all ever happened.
The Culture Vampire is a weak, shrivelled thing that survives through it's ability to manipulate the Absolute Culture Field.
The creature begins with d6 rules in place. If you attempt to fight it, the vampire can create one new rule per round, and remove 1 rule per day.
A rule is a dominant cultural expectation that everyone within the vampire's culture will obey unthinkingly and without question. They don't even realise they're doing anything strange. The action is automatic and habitual. To break it would be unthinkable. The creature itself must, of course, obey it's own rules.
Write the rules on a whiteboard or piece of paper nearby. The specific wording does matter. Here is a table of example rules for you to use, but feel free to invent your own that fit the dominant culture of your setting better.
- You can't attack anyone of higher social status than you, even in self defense.
- You cannot refuse someone of higher social status if they make a polite request for your blood.
- Your items are the property of the highest social status individual in the room.
- You cannot hide, sneak, or attempt to use stealth in any way.
- You cannot run - only walk at a slow, dignified pace, while making polite conversation.
- You cannot harm or destroy items or property in any way. (People are fair game). If an item or piece of property would be harmed or diminished in value, you must do everything in your power to prevent it.
- You cannot commit any action that would cause someone to lose money, or potential profits. To do so is the most grievous sin.
- When someone of higher status says something, you must agree with them and act as if they are correct, even if they are obviously wrong.
- When someone of higher status commits a crime, it wasn't their fault. You must do everything within your power to cover up that crime and ensure they are not punished for it, even if you have to take the blame.
- Whenever someone of higher social status makes a mistake, you must ensure that they are shielded from all consequences of said mistake.
- Once per round, when someone of higher social status suffers damage or a negative status effect (for example, they fail a saving throw and become poisoned) a lower status individual nearby must take the penalty instead.
- Anything that causes you to lose face or status is the most terribly thing imaginable. It causes you to take physical damage.
- The Family Unit is the most important thing on earth. You must always obey your mother and father and shield them from anything that would cause them to lose face.
- Your religion is the most important thing on earth. You must obey all religious tenants.
- If a person of higher status attempts to destroy you, you must assist them. For example, if they fail to hit you, you must make an immediate attack roll against yourself.
- You cannot notice strange, bizarre or supernatural things when they happen. Your mind simply blanks itself. Moments after you see it, you forget it, and go about your business.
- Any victim of a highest status individual's actions deserved everything they got. They must be shunned, removed from society, ignored, destroyed. They are no longer a person.
- A set of people chosen by the vampire are now Untouchables. This could be people of a certain social class or profession (eg Adventurers), people from a specific district or place, etc. No aid can be offered to them. They cannot be touched or talked to. They must be shunned and ignored.
- Consuming food or drink in front of other people is terribly gauche. You must never admit that you actually eat food. People will make a big show of destroying their food and drink for social clout. Meals are eaten secretly and with great guilt.
- The Vampire's appearance (Shrivelled, sunken, gaunt, a hollow corpse-shell) is now the ideal physical form - the height of beauty and fashion. It defines all beauty standards. People will go to great lengths to look like the vampire. It will be fawned over by fans.
The vampire, of course, will usually be the highest status person in the room. But the PC's could use it's rules against it if they find a person of higher social status, or somehow become higher social status themselves.
The rules get stronger when there are a lot of people from the dominant culture who can see you. They grow weaker when you're alone or surrounded by people from a different culture. If you're alone with the vampire, or your PC isn't from the hegemonic culture, you can make a Wisdom saving throw to ignore a rule for 10 minutes. PC's from a totally different and alien culture may get advantage on this roll, or ignore the rules entirely at your discretion.
Anyone who does disobey these rules or attempt to rebel against them in any way is seen as crazy, dangerous, a fool, unhinged. Everyone will agree that they must be removed and taken care of, for their own safety and the safety of others.
The force of the rules will usually extend to the boundaries of a single city, town or dungeon level. More powerful Culture Vampires can extend their rules further and further - a nation, an entire empire. While in the area of influence, you must obey the rules as long as someone can see you. You can break the rules in private, with great shame and guilt.
The vampire will usually be attended by large crowds of attendants, guards, assistants and yes-men. It doesn't like to be alone.