Amazon's original pitch for the television rights to J.R.R. Tolkien's 'The Hobbit' and 'The Lord of the Rings' novels was to make the series a new adaptation of the latter (effectively a retelling of The Lord of the Rings: The Fellowship of the Ring (2001), The Lord of the Rings: The Two Towers (2002) and The Lord of the Rings: The Return of the King (2003)), but the Tolkien estate rejected this proposal. Amazon finally obtained the rights under the conditions that the series be distinct from Peter Jackson's earlier adaptations, and that they couldn't contradict anything that Tolkien had previously written. Early ideas that were proposed included prequel stories featuring characters such as Aragorn, Gimli and Gandalf, but the showrunners preferred to focus on important untold events from the novels' lore rather than simple side stories, so they settled with the studio that the series would take place during the books' Second Age. Since they didn't have the rights to Tolkien's 'The Silmarillion', 'Unfinished Tales' and 'The History of Middle-earth' (which explore the First and Second Ages), they checked the Lord of the Rings novels and appendices for passages about any references to the Second Age in which they could set their story. They consulted with the estate and several Tolkien lore experts (including grandson and novelist Simon Tolkien) about the inclusion of new characters and plot elements.
In J.R.R. Tolkien's "Concerning Hobbits," there are three different breeds of Hobbits: Harfoots, Stoors, and Fallohides. Harfoots are the breed depicted in The Rings of Power. Like the Hobbits seen in the Third Age stories, these Second Age Harfoots share the same love of song, dance, and light-hearted humor. One way they differ is that Harfoots lead a more nomadic and migratory lifestyle, and they prefer to hide away from people and creatures they don't know.
The series is expected to be the most expensive TV show in history, with Amazon expected to spend at least $1 billion on its production.
The forging of the series title in the trailer was done by pouring an alloy mixture of bronze and aluminum into molds of compressed sand. The pouring was filmed at 5000 frames-per-second with a Phantom Flex4K camera so it could be shown in ultra-slow motion.
Morfydd Clark, who stars in the lead role as Galadriel, is a native Welsh-speaker (alongside her series co-stars Owain Arthur and Trystan Gravelle). Late in the first season, her character can be seen shouting the command "cer" to her horse - the Welsh word for "go". The elves of Tolkien's world are often associated with Welsh and vice-versa, so it's no surprise that Morfydd slipped in a piece of her mother-tongue into the show. Galadriel is a bilingual elf, like Morfydd herself, so she felt connected to the character. She has previously spoken both how the Welsh language informed her preparation for the role and the bond she formed with her horse, Titan, on set. She told Looper in an interview: "What my Tolkien-obsessed mother was really proud of and passed on to us was that Tolkien was inspired by the Welsh." The Elvish languages of Sindarin and Quenya were influenced by Tolkien's interests in Finnish and Welsh. Tolkien was inspired more by the sounds of the Welsh language than any individual words. His influence has continued in the fantasy genre, particularly on character names.