Sanguinare Vampiris is the disease inflicted upon people by contact with vampires including, but not limited to:
- Being bitten
- Taking a wound from claws or other natural weapon
- Having a vampire's personal variation of blood magic being used upon them
In short, any contact with a vampire's blood, body, or magic, will transmit the disease.
If a target is introduced to any contact with a Vampire in the above-mentioned ways, the target must succeed on a DC 13 Constitution Saving throw. On a failure, they contract Sanguinare Vampiris.
A target infected with this disease begins to show symptoms at dawn after being infected. These symptoms include general weakness and weariness while the sun is out and a deep hunger for blood. These symptoms persist for 3 days. At any point within these 3 days, there is the chance for a cure. One must find a practitioner of magic to have the disease removed. At the end of the 3 days, if the target is not cured, the disease transitions to a new stage, and the victim is now a vampire.
Once a Vampire, the symptoms become something more, imparting the new vampire with the following traits:
- Regeneration: The vampire regains 10 hit points at the start of its turn if it has at least 1 hit point and isn't in sunlight. If the vampire takes radiant damage or damage from holy water, this trait doesn't function at the start of the vampire's next turn.
- Sunlight Sensitivity: While in sunlight, the vampire has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.
- Forbiddance: The vampire can enter a residence without an invitation from one of the occupants, but if they do, they have disadvantage on any and all rolls made with a d20 as the threshold of the home saps their strength.
- Stake to the Heart: If a piercing weapon made of wood is successfully driven into the vampire’s heart, the vampire is considered paralyzed until the stake is removed.
- Bite: The vampire gains a natural weapon called "Bite." With their Bite, a vampire deals 1d4 + STR necrotic damage. A target must be grappled to be attacked with a Bite. On a hit, the target's HP Maximum is reduced by the damage amount and the vampire regains as many hit points. The HP max reduction persists until a long rest is taken. If damage from a Bite brings a target to 0 HP, they die.
- Misty Escape: When it drops to 0 hit points, the vampire
transforms into a cloud of mist (as in the Shapechanger trait) instead
of falling unconscious, provided that it isn’t in sunlight. If it is dropped to 0 hit points by radiant damage, this effect does not trigger, and the vampire is, instead, destroyed. If it can’t transform, it is, instead, destroyed.
While it has 0 hit points in mist form, it can’t revert to its vampire form, and it must reach its resting place within 2 hours or be destroyed. Once in its resting place, it reverts to its vampire form. It is then paralyzed until it regains at least 1 hit point. After spending 1 hour in its resting place with 0 hit points, it regains 1 hit point. The rest of its hit points are regained over a period of 1d4 hours. - While a Vampire, you have resistance to cold damage, immunity to necrotic damage, and are vulnerable to fire damage.
Regardless of your class, as a Vampire you know the spell Blood Drain. You can cast it, twice per day, as a 1st Level spell, without using material components or a spell slot. All damage dealt by casting the spell in this way restores your own HP by the same amount.