Inheritance laws in the Seven Kingdoms are not clear cut. According to George R. R. Martin, “The short answer is that the laws of inheritance in the Seven Kingdoms are modelled on those in real medieval history... which is to say, they were vague, uncodified, subject to varying interpretations, and often contradictory.”
Male-preference primogeniture is customary, but not binding, for most nobles. A man's eldest son is his heir, followed by his second son, then his third son, and so on. In theory, the youngest son is followed in the line of succession by the eldest daughter, after whom come her sisters in birth order. A man’s daughter inherits before her father’s brother. However, a lord also has the option of naming one of his younger sons heir, passing over his elder children, or to name the child of another as his heir. When there is no clear heir, claims can be presented to the King. The only exception is Dorne.There, no distinction is made between sons and daughters. Instead, children inherit in order of birth regardless of gender, as per Rhoynish custom. In the case of an inheriting female, her last name will be passed on to her children, instead of the name of her husband. When a ruling lord dies and leaves no clear heir, his widow might lay claim upon his lands and rule until her own death (e.g., Lady Donella Hornwood and Lady Barbrey Dustin), and in such a case, might name an heir by herself.
A lord may lay out specific terms for inheritance or pass over their offspring in his will, which may invite legal wrangling after their death, and potentially violence during it. For instance, Lord Tywin Lannister preferred his elder son, Ser Jaime Lannister, to be the heir to Casterly Rock, and as such refused to acknowledge the claim of his younger son, Tyrion, despite custom disqualifying Jaime due to being a member of the Kingsguard. Another example is Lord Wyman Webber, who declared in his will that his daughter and only heir, Rohanne, had to be wed by a specifically determined time in order to keep her inheritance. If she were to remain unwed passed the determined date, her inheritance was set to pass on to another relative. Lady Jeyne Arryn also wrote a last testament stating that her rebellious cousin, Ser Arnold and his son Eldric should be passed over for her more distant cousin, Ser Joffrey. However, a war of succession in the Vale ensued upon her death, between Ser Arnold, Ser Joffrey, and another claimant, Isembard Arryn.
The role of legitimised bastards throughout the Seven Kingdoms is also unclear i.e., whether they follow trueborn children, or join the line of succession in order of birth as if they had been trueborn all along.[24] Legitimisation, once made, is irreversible. The claims of legitimized bastards can present dangerous consequences for trueborn relatives, a famous example being the claim of the legitimized bastard son of King Aegon IV Targaryen, Daemon I Blackfyre, whose descendants sought to claim the Iron Throne from Aegon’s trueborn descendants for five generations. While unlegitimised bastards have no legal claim, they may still threaten legitimate descendants' inheritance. The illegitimate Jon Snow's decision to join the Night's Watch pleases Catelyn Stark, because Jon will never father children who might contest her grandchildren's inheritance of Winterfell.
Heirs born into a different house drop their birth surname when they come into their inheritance, adopting the name of the inherited house as their own. For example, Joffrey Lydden adopted the name Lannister upon marrying the heiress of that house, while the possibility of Beren Tallhart adopting the Hornwood name upon inheriting the Hornwood lands is considered.
Loss of succession right
The right of succession may be renounced. A famous example is Prince Duncan Targaryen, the eldest son of King Aegon V Targaryen, who broke his betrothal to marry Jenny of Oldstones. When made to choose between his right to the throne and his wife, Duncan renounced his claim, making his younger brother, Jaehaerys, the new heir.
A king or lord can also name another as his heir (e.g. King Aerys II Targaryen naming his younger son Viserys Targaryen as his heir over his grandson Aegon Targaryen following the death of his eldest son, Rhaegar, Aegon’s father, or Lord Walder Frey’s threats to name his youngest son as his heir, passing over all other sons and (great)grandsons). However, even in such cases, claims might still be made later on.
Right of succession is also lost when someone becomes a member of the Night's Watch, a septon, a septa, a silent sister, a maester, or joins the Kingsguard. Traitors may be attainted, in which case even his descendants would lose their right to succeed.
Inheritance of the Iron Throne
Inheritance customs for the Iron Throne differ from the inheritance customs in the rest of Westeros. The inheritance rights of females with regard to the Iron Throne have changed over the years, as a result of several power struggles.
Females have, over the years, been declared heir to the throne, both directly and indirectly. When King Aegon I Targaryen's eldest grandchild, Princess Rhaena Targaryen, was born in 23 AC, she was regarded as second in line to the throne (her father, Prince Aenys Targaryen, being King Aegon's immediate heir), placed before her father’s half-brother Maegor in the line of succession. Upon the birth of Aenys's second child, Prince Aegon Targaryen, Aegon became the first in line after Aenys. When King Maegor I Targaryen was still childless in 47 AC, he named his niece, Princess Aerea Targaryen, as his heir. And in 105 AC, following the death of his newborn son, King Viserys I Targaryen named his daughter Rhaenyra, his only surviving child at the time, as his heir, had the lords of the realm swear fealty to her, and refused to alter the line of succession even after the birth of three sons in a second marriage.
However, despite these examples, towards the end of the first century of the Targaryen Dynasty, the first hesitations towards female inheritance of the throne arose. King Jaehaerys I Targaryen's eldest son, Prince Aemon Targaryen, had been the king's heir until his death in 92 AC. Aemon had only had one child, a daughter named Rhaenys. When naming his new heir, King Jaehaerys I chose his next eldest son, Prince Baelon, over Aemon's daughter Rhaenys. When Baelon died in 101 AC, a Great Council was called, in which the Westerosi lords voted on the succession. The lords voted for Baelon's son Viserys over Rhaenys's son Laenor Velaryon, by a vote of twenty to one. The lords felt that a male line was preferred over a female line, and believed that a precedent was set stating that the Iron Throne could not pass to a woman, or to the male descendants of a woman. Ironically, it was Prince Viserys, by then crowned king, who later disregarded these precedents by naming his daughter Rhaenyra Targaryen as his heir despite having three healthy sons by a second marriage. Viserys's decision would eventually lead to the civil war known as the Dance of the Dragons.
This war began when Viserys I's eldest surviving son, Aegon II Targaryen, claimed the throne after Viserys's death, dividing the loyalties of the kingdoms between Aegon II and Rhaenyra. Aegon II's sons, Jaehaerys and Maelor, both died during the war, as did Rhaenyra's eldest three sons (Jacaerys, Lucerys, and Joffrey Velaryon), while her youngest son, Prince Viserys, was presumed dead. In an attempt to end the war, Lord Corlys Velaryon ensured that Aegon II's only remaining heir, his daughter Jaehaera, was betrothed to Rhaenyra's son, Aegon the Younger, and that both were named Aegon II's heirs. While the King agreed to do so, he also arranged a betrothal of his own. Even though Aegon II died before fathering any more children, and the marriage between Aegon the Younger and Princess Jaehaera did occur, the marriage ended childless, and Aegon the Younger reigned as monarch as King Aegon III Targaryen after Jaehaera's death.
The agnatic principle laid down in the Great Council of 101 AC was slightly modified after the Dance of the Dragons. Thereafter, according to a semi-canon source, women came after all men in the Targaryen succession, i.e., women could only succeed if the entire male line of House Targaryen became extinct. Nonetheless, several females claims have since been considered. In 171 AC, following the deaths of Aegon III's two sons Daeron I and Baelor I, both childless, the claims of Aegon III’s three daughters were considered. However, with the Dance of the Dragons still fresh in their minds, the claims of the three women were passed over and Aegon III’s brother Viserys II ascended the throne. Another few decades later, King Maekar I Targaryen died without a clearly established heir. His simple-minded granddaughter Vaella Targaryen, the only child of Maekar's eldest son, was seen as a possible claimant. However, her claim was quickly dismissed.
In 283 AC, the Sack of King's Landing during Robert's Rebellion led to the death of King Aerys II Targaryen. His sister-wife, Queen Rhaella Targaryen, pregnant with Princess Daenerys, was at Dragonstone with Aerys's surviving son, Prince Viserys, who was declared king on the island fortress. Robert I Baratheon, however, acceded the Iron Throne by right of conquest, chosen as claimant by the rebels due to his Targaryen descent, as he was the grandson of Princess Rhaelle Targaryen, the youngest daughter of King Aegon V Targaryen, which gave him the better claim. Nonetheless, the exiled Viserys declared his sister Daenerys his heir, naming her Princess of Dragonstone, and following Viserys's death, Daenerys has declared her own claim for the Iron Throne.
It is possible that some of the kingdoms of old practiced different customs regarding the inheritance of the throne. The heir of King Argilac Durrandon, the last Storm King, was his maiden daughter, Princess Argella,[30] while on the Three Sisters, Marla Sunderland was installed as Queen shortly after Aegon's Conquest.
Age of majority
For both boys and girls, sixteen is the age of legal majority. From that point, there are referred to as a "man grown" and "woman grown".
However, for girls, there are exceptions. A girl who has had her first flowering (i.e. first menstruation) is considered to be fit for both marriage and consummation of the marriage. Most highborn girls have their first flowering at the age of twelve or thirteen, bringing them in a somewhat ambigious position. They are considered to be "part child, part woman", and can be referred to as a "maid" or "maiden", and, even if she has not yet reached the age of sixteen, a "woman grown".
NOTE: For sim purposes, the age of majority for both men and women has been changed under the law to 18 years of age for compliance with Linden TOS. As such, the age of a young woman's first flowering is irrelevant as she is not of consumation age until age 18.
Young highborn boys can be sent away for fosterage to other noble families. While there are exceptions (e.g., Quentyn Martell), it appears that boys who have reached the age of majority are free to go where they like, thereby ending their fosterage.
Ruling lords and ladies who inherit while still in their minority usually have a regent, who serves as the decision-making ruler until they come of age.