Spoilers ahead for Star Wars: The Last Jedi. Rose Tico is not only the Resistance's newest hero in The Last Jedi — she's also the Resistance's winner of Best Accessories. Not only does she have a super powerful electrical tool/stun gun (and she's not afraid to use it), she also has a meaningful family necklace and a very important ring. In fact, Rose's Rebel rebel ring in The Last Jedi is crucial to the Resistance.
Rose's ring is pretty innocuous at first glance, but it ends up saving Rose and Finn on their mission to Canto Bight, the casino for the rich elite of the Galaxy far far away — aka weapons manufacturers — introduced in The Last Jedi. After getting caught infiltrating the casino, Finn and Rose escape from the underground prison area and into the stables where the Fathiers are being held. (Fathiers are basically like space horses, bred in captivity by the rich on Canto Bight and forced to race.) Rose takes an instant liking to the large animals — Finn is undecided — and, in an attempt to get away from the guards searching for them, she opens one of the stalls only to find a little kid with the Fathier. Clearly a slave or indentured servant, the child is fearful of strangers and unsure of what to do. He's just about to press an alarm button in the stall and summon the guards when Rose stops him. "We're with the Resistance," she tells him as she reaches for her ring. With one flick of a switch, the innocent design on the ring is replaced by the Rebel symbol.
The history of the ring, namely how Rose acquired it, is never detailed in the film, but fans can find more information in Star Wars: The Last Jedi: The Visual Dictionary, a new book Pablo Hidalgo. As reported by Screen Rant, the Visual Dictionary states that the ring was passed down for generations and over decades before it made its way to Rose. It was originally an accessory used by members of the Imperial Senate during the Galactic Civil War so they could secretly declare their Rebel allegiance. This is exactly how Rose uses the ring in The Last Jedi, but with every new generation, the meaning of the Rebel symbol and the form of the Resistance changes.
At the end of The Last Jedi, Rose's Rebel ring takes on a slightly new meaning. Instead of identifying existing members of the Resistance, it symbolizes the hope of a new generation that will eventually join. The audience is taken back to Canto Bight, where three of the young children working the stables are huddled on a dirty floor, playing with handmaid action figures, telling the story of Luke Skywalker and Darth Vader. They are quickly ordered back to work, and as the little boy who helped Rose goes outside to sweep the runway leading out to the race track, he appears to summon the broom into his hands using the Force. He steps outside to look up into the night sky, the ring sitting proudly on his hand.
Not only could this boy be a sign of a new generation of Jedi outside of the Skywalker bloodline, he is also a symbol of the growing Resistance. Throughout The Last Jedi, the Resistance takes many hits, losing an entire fleet of bombers and countless ships and personnel. There are only a handful left in the main team, with few allies scattered across the galaxy. But thanks to Rose and her ring, it looks like the Resistance is about to get an entire generation of new recruits.