Vampire player race
Steve Runyon, 2020, http://breadsandwich.net

RACES

Vampire
***Ability Score Increase***. Your Charisma score increases by 2 and one other ability score of your choice increases by 1.
***Age***. Vampires don’t mature and age in the same way that other races do. You always appear to be the same age and maturity as when you became a Vampire.
***Speed***. Your base walking speed is 30 feet.
***Past Life***. Choose another race besides this one, which must be humanoid and have blood. Before you became a vampire, you were a member of this race. Your size, height, and weight are the same as a typical member of that race. If your Past Life race has subraces, you can select one, but it confers no benefits.
***Undead Nature***. Your creature type is undead, in addition to humanoid. You don't need to eat, drink, or breathe. You have resistance to necrotic damage. 
***Vampiric Instinct***. You have fangs and claws that are natural weapons, which you can use to make unarmed strikes. If you hit, claws deal 1d6 slashing damage and fangs deal 1d6 piercing damage. They can be grown or retracted as a bonus action. You also have proficiency in the Perception skill.
***Superior Darkvision***. You can see in dim light within 120 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray.
***Sunlight Hypersensitivity***. You have disadvantage on attack rolls and ability checks when you are in direct sunlight. In addition, you take 1d6 radiant damage when you start your turn in direct sunlight.
***Harmed by Running Water***. You take 1d6 acid damage when you start your turn in running water.
***Forbiddance***. You can't enter a residence without an invitation from one of the occupants.
***Spider Climb***. You can climb difficult surfaces, including upside down on ceilings, without needing an ability check.
***Shapechanger***. If you aren't in sunlight or running water, you can use your action to polymorph into a bat. You can stay in this form for up to 1 hour. You then revert to your normal form. You can revert to your normal form earlier using an action. You automatically revert if you fall unconscious, drop to 0 hit points, or die. Your game statistics (including hit points and Hit Dice) are replaced by the statistics of a Bat (MM 318), but you retain your alignment, personality, and Intelligence, Wisdom, and Charisma scores. You can use this feature once per long rest.
***Vampiric Seduction***. As an action, you can target one humanoid you can see within 30 feet of you. If the target can see you, they must succeed on an a Wisdom saving throw or be charmed by you for 1 hour. The DC is 8 + your proficiency bonus + your Charisma modifier. The charmed target regards you as a trusted friend to be heeded and protected. When the effect ends, the creature knows it was charmed by you.
***Feeding***. As an action, you can attempt to feed off a target's blood. Make a melee attack on a humanoid target with blood within 5 feet of you using your fangs. If the target is willing, grappled by you, incapacitated, or restrained, the attack automatically hits. If the attack hits, you deal an additional 2d8 necrotic damage to the target and heal for the amount of necrotic damage done. If this effect reduces the target's hit points to 0, they die and if they are buried in the ground rises the following night as a Vampire, permenantly charmed by you.
***Blood Thirst***. You are required to feed in order to live. The longer you go without feeding, your thirst grows and you grow weaker and more desperate. There are five stages. If you go 24 hours without feeding, you progress to the next stage. When you feed you are reset to "Sated". You gain the following traits based on the stage you are in. 
*Sated*. You have proficiency with the Stealth skill. If you are already proficient in the skill, you add double your proficiency bonus to checks you make with it. You have resistance to bludgeoning, piercing, and slashing damage from nonmagical attacks.
*Thirsty*. Your fangs and claws deal an additional 1d8 necrotic damage. You heal half as much from healing spells. You have resistance to bludgeoning, piercing, and slashing damage from nonmagical attacks.
*Parched*. Your fangs and claws deal an additional 2d8 necrotic damage and cannot be retracted. Your Intelligence, Wisdom, and Charisma scores each decrease by 1. Your Strength, Dexterity, and Constitution scores each increase by 1. You heal half as much from healing spells.
*Blood Starved*. Your vampiric traits become more pronounced and monstrous, and clerics who are against undead are likely to attack you. Your fangs and claws deal an additional 2d8 necrotic damage and cannot be retracted. Your Intelligence, Wisdom, and Charisma scores each decrease by 2. Your Strength, Dexterity, and Constitution scores each increase by 2. You are no longer healed by healing spells. You are vulnerable to radiant damage (including from Sunlight Hypersensitivity).
*Bloodfiend*. In addition to the traits gained from Blood Starved, at the start of each day, make a Charisma saving throw. The DC for this save starts at 10 and increases by 1 each day you remain at Bloodfiend. If you fail, you become completely overcome with bloodlust and feral. You lose control of your character.
***Languages***. You can speak, read, and write Common and one other language of your choice.

Alternative rule:
The damage for Sunlight Hypersensitivity and Harmed by Running Water increases by 1d6 when you reach 5th level, 11th level, and 17th level.

Alternative rule:
Add the following feature:
***Resting Place***. Choose a location to be your resting place. This is usually where you were buried when you were made into a Vampire. You can move this resting place by moving your coffin or a significant amount of grave dirt to another location. While you are resting in your resting place, you are immune to all damage but if a piercing weapon made of wood is driven into your heart you are paralyzed until the stake is removed.

Rules note:
A "healing spell" is a spell that restores hit points. Spells that give temporary hit points, such as False Life and Negative Energy Flood, are not healing spells.


FEATS
(A DM can decide which of the Daywalker or Shadowwalker feats are available to players)

Daywalker
Prerequisite: Vampire
Your vampiric blood has become even more powerful, to the point where sunlight no longer harms you
You gain the following benefits:
* You no longer have take damage from sunlight.
* While you are Sated, you no longer have disadvantage on attack rolls and ability checks when you are in sunlight.

Shadowwalker
Prerequisite: Vampire
You gain access to a new vampiric power, where you can briefly become an entity of pure shadow to move in the darkness.
When you are in dim light or darkness, as a bonus action, you can teleport up to 120 feet to an unoccupied space you can see that is also in dim light or darkness.

Vampire Lord
Prerequisite: Vampire
As an action while not in sunlight, you transform into a bat-like humanoid being, growing wings and horrible claws. When you transform, each creature of your choice within 30 feet of you must succeed on an a Wisdom saving throw or be frightened of you for 1 minute. The DC is 8 + your proficiency bonus + your Charisma modifier. In addition, you gain the following benefits for 1 minute or until you use an action to transform back:
* You gain a flying speed of 60 feet.
* You gain temporary hit points equal to your Charisma modifier at the start of each of your turns.
* Your fangs and claws natural weapons each increase to dealing 1d10 damage of their respective damage type.
* When you take the Attack action on your turn, you can make one additional attack with your claws.
* Whenever you use the Feeding action, the duration of this transformation increases by 1 minute.
You can use this ability once per long rest.


MAGIC ITEMS

Chalice of Blood
Wondrous item, Uncommon (requires attunement by a Vampire)
As an action, a Vampire can swirl the contents of the chalice to to fill the chalice with the blood of any humanoid they had previously fed on. You can use this feture once very 24 hours.