Editor's Note: The following contains major spoilers from George R. R. Martin's Fire & Blood books.House of the Dragon may be based on George R. R. Martin's Fire & Blood, but they aren't identical. Season 1 made a few changes, from messing with the age of the characters to adding the all-important Prophecy of Ice and Fire. But many of the changes are necessitated by the nature of the novel. The story is a historical retelling based on multiple different accounts that don't have all the information and occasionally contradict one another. So far, the show follows the major plot points from the book, but they weren't afraid to change things when it came down to it. Some changes improved the show, like the friends-to-enemies relationship between Alicent (Olivia Cooke) and Rhaenyra (Emma D'Arcy). As House of the Dragon continues, there will be more changes. Though it's impossible to know what those will be, there are several likely candidates.
Rhaena
Rhaena Targaryen (Phoebe Campbell) is Daemon's (Matt Smith) daughter and the only Targaryen without a dragon of their own. In the books, Rhaena takes a back seat during the conflict, hiding in the Vale while the other members of her family wage war, eventually hatching a dragon egg for herself. However, the show emphasized her desire for a dragon and introduced the idea of her claiming one. While several fan theories have ventured guesses on how that may be possible, there is no telling what might happen. But, as House of the Dragon is making a point to focus on the women of Westeros, it seems likely that Rhaena will have more to do as the show goes on.
Addam Velaryon Claiming Seasmoke
One change made in Season 1 could cause problems for Season 2. Fire & Blood never hints that Laenor Velaryon (John Macmillan) might not be dead, yet in House of the Dragon, he only fakes his death. If Laenor is alive, it could make it difficult for the bastard-born dragonseed, Addam Velaryon, to claim Laenor's dragon, Seasmoke. Dragons cannot have two riders, and the connection between Laenor and Seasmoke should keep the dragon from being fooled by Laenor's fake death. Laenor could die in Essos, or Addam's story could be the same with a different dragon. Some fans have suggested that Laenor will return disguised as Addam. However, if the show proceeds with this plotline, they will have to pick up the storyline from their last change.
Nettles
Yet another dragonseed that may not be the same is Nettles. This is an interesting one because her variation is unavoidable due to the unreliable narrator. The different narrators of Fire & Blood don't know much about Nettles, and the rumors surrounding her tell different stories. In some versions, she is Daemon's base-born daughter, but in others, she is his lover. While Targaryen incest is common, relationships between parent and child are not (at least they have some boundaries). House of the Dragon will need to choose one direction if they don't go their own way. One fan theory suggests that Nettles will be cut in favor of Rhaena. However, the rumor of Nettles and Daemon being lovers is an important part of the story, as it leads Rhaenyra to turn on the dragonrider and order her death. Certainly, Daemon and Nettles being in a relationship is the most common version of the story. Season 2 will have to decide how to tell Nettles' story in a definitive way.
Jace and Sara Snow
As House of the Dragon adapts Fire & Blood, they will face many contradictions. Perhaps one of the more ludicrous variations happens during Jacaerys' (Harry Collett) time at Winterfell. While all three sources, Septon Eustace, Grand Maester Munkun, and Mushroom, agree that Jace and Cregan Stark became friends as the Prince convinced the Warden of the North to support his mother, Mushroom didn't stop there. His version includes Jace marrying Cregan's bastard sister Sara Snow. No other version can confirm the existence of such a person, and marrying Sara would mean Jace breaks his betrothal to his stepsister and, seemingly, his friend, Baela Targaryen (Bethany Antonia), which won them the support of the Velaryons. It's a strange addition to the story, but House of the Dragon has gone with Mushroom's wild versions before, like when Daemon took Rhaenyra to a brothel. It will be interesting to see what the show does when it comes to Sara Snow.
Aegon Dismissing Otto
Throughout Season 1, Otto Hightower (Rhys Ifans) was a driving force for the Greens. His desire to get his blood on the Iron Throne and his manipulation of his daughter was a key factor in beginning the war. But, in Fire & Blood, as the war went on, Aegon II (Tom Glynn-Carney) became unsatisfied with Otto's performance as Hand of the King and dismisses him for Criston Cole (Fabien Frankel). This is especially interesting, considering Alicent and her father have already disagreed when it comes to who will influence Aegon. With Alicent being the lead character of the Green faction in Season 1, it seems likely that House of the Dragon will expand her part, so she remains a lead for the rest of the show. This conflict is a perfect way to insert Alicent. Aegon's dismissal of Otto, who has his own designs, and his choice of Cole, who is loyal to Alicent, could all be done under his mother's manipulation. While this would be a small change, it would be significant nonetheless, as it would be a starting point for Alicent moving forward.
Rhaenyra's Exceptionalism
From focusing on the woman's "battle" of childbirth to that chilling conversation between Rhaenys and Alicent, it's no secret that House of the Dragon is offering a new perspective on women in the world. However, in Fire & Blood, Rhaenyra doesn't support other women. When Lady Stokeworth and Lady Rosby attempt to get her to support their claims above their male relatives, Rhaenyra claims that her inheriting the Throne above her half-brothers is an exception, ignoring the other women. This directly contradicts what the show is trying to do, so a small change seems to be in order.
Vermithor
Vermithor is the second-largest dragon and the former ride of Jaehaerys I. He appears in the Season 1 final when Daemon sings to him. Later in Fire & Blood, Hugh Hammer claims Vermithor, fighting for Rhaenyra before betraying her and joining the Greens. Despite being the only dragon who could stand a chance against the battle-worn Vhagar, Fire & Blood never tells of a fight between the two. House of the Dragon could change that. The best thing the show can do is offer epic dragon fights the Game of Thrones couldn't, as most dragons were extinct. Fans have debated if Vhagar of Vermithor would win in a fight since Vermithor's appearance. Of course, this would be a major departure from the book if they chose this route. But it would make a great dragon battle.
The Brothel Queens
Another of Mushroom's additions is the story of Rhaenyra forcing Alicent and Helaena (Phia Saban) into a brothel for comments about her sons being bastards. The story claims that after Rhaenyra conquered King's Landing, Alicent tried to negotiate peace. But when she angered Rhaenyra, Mysaria (Sonoya Mizuno) convinced Rhaenyra to send both captive queens to a brothel where they would be impregnated with bastards. While this story is told among the small folk of King's Landing, the in-world historian, Archmaester Gyldayn, believed it to be a rumor to discredit Rhaenyra rather than the truth. This is another case where some say it happened and others say it didn't, so House of the Dragon will need to pick a direction.
Helaena's Suicide
In Fire & Blood, Helaena kills herself by jumping from a window after six months of captivity. No one can say for sure her reasons, as her situation didn't seem to change from one day to the next, but there is much speculation. Grand Maester Munkun cites the hanging of Ser Thoron and Ser Denys, whose bodies she could have seen from her confinement. Mushroom claims it was because she discovered she was pregnant after the brothel queens incident. Septon Eustace suggests that she had just learned of her son Maegor's death. House of the Dragon will not leave it a mystery, though it's not clear what story they will support.
Jaehaera's Death
Though after the end of the war, Jaehaera's death is significant to the story and could likely make it into the series. It's seemingly unnecessary, as the uniting of the Greens and the Blacks should be symbolic, but even so, Jaehaera dies. The facts mirror her mother's death, as does the mystery behind it. Rumors abound claiming Jaehaera's death was murder rather than suicide, with three primary suspects, Lord Unwin Peake, Mervyn Flowers, and Tessario the Tiger. If the show makes it this far, they will need to decide if she was murdered and by whom.