The Hobbit was originally published in 1937, and the first Lord of the Rings book wouldn't be published until 17 years later, in 1954. During this time gap, J.R.R. Tolkien began to rethink the nature of his ring. It became the center of the plot of his new series, which would see Bilbo's nephew battle against the terrible temptation and power that was the One Ring. From here, an entire universe and fantastic lore was born. The Lord of the Rings described the Dark Lord Sauron, and his evil intention centered around Rings of Power—but this didn't fit with the part Gollum had played in The Hobbit.

If the One Ring was a source of power and terrible temptation, then Gollum shouldn't have been able to offer it as a prize for Bilbo so willingly. The Lord of the Rings changed the ring from a useful trinket to a source of great power. This, in turn, retconned Gollum's character. He no longer seemed like a whimsical creature who enjoyed living in a cave and catching fish. He was a victim of the One Ring—something the established version of The Hobbit just didn't communicate.