HBO's House of the Dragon has several Call Forwards to its parent show Game of Thrones:
Season 1
- King Viserys Targaryen believes in the prophecy of the Song of Ice and Fire about a great and cold threat that will descend upon Westeros from the North, which will happen more or less 200 years later in the form of the Night King and his armies of White Walkers and Wights.
- Viserys also says a Targaryen will have to be on the Iron Throne to unite Westeros and prevent this, which will end up only partially true (said Targaryen — Daenerys — will be on the throne of Dragonstone and de facto control most of the Seven Kingdoms when it happens, at least), and he owns the Valyrian steel dagger that would be used by Arya Stark.
- Right as he talks about said threat, the editing of the scene has Lord Rickon Stark pledging fealty to Rhaenyra at the ceremony to officialize her as Crown Princess. House Stark will be of crucial importance in dealing with that threat.
- Additionally, Viserys ends his speech with “Promise Me this, Rhaenyra. Promise me.” Calling to mind Lyanna Stark’s last words, specifically about Jon Snow, a Stark on his mother’s side and a Targaryen on his father’s.
- Alicent attacks Rhaenyra and her son with a Valyrian steel dagger, in significant part because Alicent knows he is a bastard who destroys Rhaenyra's claim to the throne. This majorly contributes to starting a civil war. In Game of Thrones, an assassin attacks Catelyn and Bran Stark using the same dagger, in significant part to cover up that Joffrey is a bastard, and this too contributes to a Civil War.
- About the Starks, Rhaenyra Targaryen acknowledges House Stark's reputation as unwavering oathkeepers. In Game of Thrones, oaths are the lynchpin of the Starks' storyline, with Ned dying because he blindly held onto one, Robb losing a war and his life because he broke one, and Jon getting out of one by temporarily dying. Cregan Stark's appearance and commitment to Rhaenyra's cause at the start of Season 2 cements this.
- When Daemon Targaryen threatens his Kingsguard, he warns them that if they betray Rhaenyra, they will die screaming. This is exactly what Daenerys will tell her Dothraki (about their enemies, but still) in the first season's finale of Game of Thrones.
- Rhaenyra says that she does not want to rule over a kingdom of ash. Her descendant Daenerys will make a similar statement.
- The final shot of the Season Finale, when Rhaenyra gives a Death Glare into the camera, bares a striking resemblance to Daenerys’s expression at the end of Episode 4 of Season 8 after losing Missandei, both once-peaceful rulers who lost someone close to them and are now ready to bring Fire and Blood upon their enemies.
Season 2
- The Greens' usage of scorpion ballistae to protect against the Blacks' dragons makes In-Universe sense, as their usage against dragons is still within recent historyFrom the Books.... This same principle is also likely what motivated Qyburn to reconstruct them for Cersei Lannister during her brief time as Queen.
- In Episode 4, the three hounds that Daemon sees in Harrenhal are a call forward to the occupation of Harrenhal by Gregor Clegane in season 2 of Game of Thrones.
- In Episode 6, just like in "The Old Gods and the New", a crowd at King's Landing erupts into a riot against the royal family over a famine brought on by the ongoing war.
- Also in Episode 6, Aemond's refusal to recognize any authority of Alicent over the Small Council is reminiscent of Kevan Lannister's similar dismissal of Cersei: "You are the Queen Mother, nothing more." Given that Alicent is gentler than Cersei, Aemond is also more polite about it, addressing her privately.
- In the Season Finale, Admiral Sharako Lohar keeps messing with Tyland Lannister, notably by saying his name wrong on purpose. At one point she calls him "Tywin", the same as the descendant of his brother Jason who will be the head of the Lannister family by the time of Game of Thrones.
- Daemon has a vision of several important future plot developments when touching the Weirwood Tree of Harrenhal as it "bleeds", such as:
- A young Brynden "Bloodraven" Rivers (his great-grandson) as he becomes the oracle known as the Three-Eyed Raven.
- The invasion of the White Walkers.
- The hatching of Daenerys's three dragons.
- The final shot of Rhaenyra through the lattice of library shelves directly mirrors a shot of Joffrey and Margaery looking at her remains through a grate in the Sept of Baelor.
- The musical themes for the Starks and Lannisters from Game of Thrones play when their respective armies are shown marching in the final sequence. The latter, of course, is also the melody of "The Rains of Castamere", a song about Tywin Lannister's extermination of Houses Reyne and Tarbeck, which hasn't been written yet In-Universe.