Blood Purity

**Blood purity** is a system used to classify witches and wizards based on their parentage. A family is considered pureblood if the current head of the family has four magic-wielding grandparents.

## Overview

### Demographics

Currently, halfbloods make up about 25% of the population, and Muggleborns make up even less.

Muggleborns and halfbloods make up about 20% of Harry's generation, and purebloods tend not to marry outside of other purebloods. This was not always the case; at some point previously, about 50% of Wizarding children were halfblood.

The magical population in general was claimed by Draco to be dying, leading to purebloods getting married more quickly and having Heirs sooner, though this was something he said in an effort to convince Professor Flitwick to give him access to the class records.

### Magic

Purebloods are said to have generations of magical control in their blood, while Muggleborns have magic that is closer to the "source of magic," and thus more new, unpredictable, and versatile. Halfbloods are more difficult to pin down, magic-wise, though they often have Neutral wild magic from their Muggleborn parent and either Dark or Light magic from their pureblood parent. Mathematically, the average amount of magic across different blood purities isn't different.

There are very few examples of magic that purebloods can perform, but one such example is specific inheritance magic, such as a ritual allowing a pureblood to pass their magical gifts to a halfblood so that it would not die out. However, spells of this nature are very rare. A spell of this kind was attempted to be used on Harry to transfer the Metamorphmagus ability to Voldemort, but it did not work due to the blood not being pure.

## Purebloods

### Definition

The definition of how many magical parents are needed for someone to be considered pureblood changes based on who's in charge.

* Durmstrang requires a minimum of four generations of magical blood on both sides, and exceptions are not made for creature blood.
* The New Triwizard Tournament requires magical heritage up to the great-grandparent level and also doesn't count creature blood.

Many wizards and magical creatures were upset by these definitions of blood purity; one such example is the shifter community, including Blaise's mother.

### Genetics

Purebloods have "delicate features" and "distinct coloring," and may look "exotic."

Old pureblood families have genetics influenced by magic, which leads to them tending to share features. It's said that when their ancestors first harnessed magic and gave it shape, they also learned how to pass their gifts onto their offsprings without it being diluted, leading to abilities like those of Metamorphmagi becoming genetic. This lack of "dilution" applied both to magical traits and to physical traits. In the present day, this results in each pureblood family looking more alike than they might have naturally. Despite generations of intermarriage, families like the Blacks, Malfoys, and Weasleys still retain similar features, though recessive features may sometimes appear.

This explanation about traits being passed down in their pure forms is apparently what gave them the name "pureblood." One result of this is that there have not been any new magical abilities in a long time, and the existing abilities are nearly exclusive to pureblood families.

For some reason, boys are also more common in pureblood families. Percy once studied the effect on magic on the gender of firstborn children in old pureblooded families, which implies that this was caused by magic.

Pureblooded families are also affected by The Fade.

### Customs

* Purebloods generally give their family name when introducing themselves, according to Archie.
* Handshakes are not common for purebloods after initial introductions.
* Purebloods usually have long hair, though adult wizards in general do as well.
* Many purebloods have tutors before coming to Hogwarts, including in the subject of Pureblood Etiquette.
* Watches are given to male pureblood heirs when they turn eleven, and Heir rings are given when they turn seventeen.
* Pureblooded heirs often have neat, flowing handwriting.
* Pureblood women are meant to be poised and collected, even in difficult situations.
* It's considered rude for purebloods to outwardly have a preference for one gender. This is likely because of the declining pureblood population, which caused wizarding families to change their outlook on same-sex relationships, and encourage any willing pureblooded couple to have children with magical assistance.

## Characters by blood purity

### Pureblood

Note that all Hogwarts students are considered pureblood unless stated otherwise in the *Rigel Black Chronicles* regardless of their original blood status.

* Archie Black
* Sirius Black
* Regulus Black
* Diana Black
* James Potter
* Draco Malfoy
* Lucius Malfoy
* Narcissa Malfoy
* Pansy Parkinson
* Rose Parkinson
* Edmund Rookwood
* Aldon Rosier
* Alesana Selwyn
* Theodore Nott
* Blaise Zabini
* Millicent Bulstrode
* Marcus Flint
* Adrian Pucey
* Arthur Weasley
* Molly Weasley
* Bill Weasley
* Charlie Weasley
* Percy Weasley
* Fred Weasley
* George Weasley
* Ron Weasley
* Ginny Weasley
* Neville Longbottom
* Zhou Chang
* Lee Jordan
* Ernie Macmillan
* Seamus Finnegan
* Parvati Patil
* Padma Patil
* Angelina Johnson
* Alicia Spinnet
* Katie Bell
* Cormac McLaggen
* Michael Corner
* Eric Albright
* Viktor Krum
* Shang Feiyan
* Fleur Delacour
* Caelum Lestrange
* Malcolm Hurst
* Leo Hurst
* Griselda Marchbanks
* Horace Burke
* Barty Crouch Jr
* Benjamin Wates
* Tiberius Ogden
* Ulrich Albright

### Halfblood

* Harry Potter
* Addy Potter
* Severus Snape
* Tom Riddle
* Remus Lupin
* Daphne Greengrass
* Antiope
* Matheus Sousa
* Edgar Krait
* Eleni Hurst
* John Dawlish

### Muggleborn

* Lily Potter
* Hermione Granger
* Jacob Owens
* Tahiil Diric Zahi

### Squib

* Merriam
* Adam Quincy

## Notes

1. ↑ The use of "population" here is vague, but in context, Harry is likely referring only to Wizarding children or Hogwarts students; additionally, the population in general is later stated to be a different percentage.
2. ↑ Fleur identifies herself as pureblood, though she was entered under the New Triwizard Tournament as a halfblood due to her quarter-veela blood. Though she was not happy to compete as a halfblood, she entered the tournament hoping to win the world tour.

## References

1. ↑ 1.0 1.1 1.2 The Ambiguous Artifice: Chapter 12
2. ↑ 2.0 2.1 The Serpentine Subterfuge: Chapter 1
3. ↑ The Pureblood Pretense: Chapter 2
4. ↑ 4.0 4.1 4.2 4.3 The Serpentine Subterfuge: Chapter 14
5. ↑ The Ambiguous Artifice: Chapter 7
6. ↑ 6.0 6.1 The Futile Facade: Chapter 12
7. ↑ The Futile Facade: Chapter 10
8. ↑ The Futile Facade: Chapter 13
9. ↑ The Futile Facade: Chapter 6
10. ↑ The Futile Facade: Chapter 7
11. ↑ 11.0 11.1 The Pureblood Pretense: Chapter 1
12. ↑ The Serpentine Subterfuge: Chapter 10
13. ↑ 13.0 13.1 13.2 13.3 The Serpentine Subterfuge: Chapter 7
14. ↑ The Serpentine Subterfuge: Chapter 12
15. ↑ The Futile Facade: Chapter 5
16. ↑ The Ambiguous Artifice: Chapter 2
17. ↑ The Serpentine Subterfuge: Chapter 2
18. ↑ The Pureblood Pretense: Chapter 5
19. ↑ The Pureblood Pretense: Chapter 7
20. ↑ The Serpentine Subterfuge: Chapter 5
21. ↑ The Pureblood Pretense: Chapter 20
22. ↑ The Pureblood Pretense: Chapter 21
23. ↑ The Serpentine Subterfuge: Chapter 6
24. ↑ The Ambiguous Artifice: Chapter 11