During the final moments of Star Wars: The Last Jedi, Han Solo’s dice appear and disappear from the Resistance base on Crait, though it’s never fully explained how or why they vanish to begin with. In an effort to protect the Resistance from the First Order, Luke Skywalker Force projects himself onto Crait to stand against Kylo Ren. Before he duels with his nephew, Luke reunites with Leia in the base where she and the surviving fighters are stationed. There, he gives her Han Solo’s pair of gold dice.
While Han's dice have a storied past in Star Wars lore, the ability to Force project across space is a relatively new addition to the films. It existed in the now non-canon Star Wars Legends stories as a Jedi mind trick called Dopplegänger or Similfuturus. The Jedi creates a second version of themselves that they can manifest to interact verbally and physically with other people and droids. In this way, the Jedi can manipulate others’ impression of their second self. This explains how Luke projects a more youthful image of himself to Leia and C-3PO and creates a dice illusion that feels real and can be handled by multiple people. This ability requires intense concentration, effort, and control on behalf of the Jedi, so Luke can physically touch Leia while remaining impervious to blaster bolts from the First Order and Kylo's lightsaber.
After Kylo Ren’s unsuccessful battle with Luke, he and his troops storm the newly-abandoned base and find the dice. It’s interesting to note that while Luke ends his body’s projection and becomes one with the Force, the projection of the dice remains long enough for Kylo to pick them up and feel their impact. Han's gold dice don’t vanish right away because Luke is still exerting the rest of his energy to project them, even as he dies to merge with the Force. This is his last chance to connect with Kylo and bring him back to the light by showing him tangible evidence of his father. The dice projection vanishes because Luke is no longer there to manifest them.
The disappearance of Han's dice also serves as a reminder to Leia and Kylo that Han is still with them. Even though Luke, Leia, and Han do not make an appearance all together in the sequel trilogy, the dice represent their spiritual connection. It’s a beautiful little moment for the siblings, since this is the last time they are together honoring Han’s memory. For Kylo, the dice are Kylo’s personal reminder of happier, innocent days of his childhood as Ben Solo, and of the father he killed. Jason Frye’s Star Wars: The Last Jedi Expanded Edition novel touches upon Kylo’s involvement with Han’s dice. As a young boy, he was Han’s shadow, “carrying the dice from the Millennium Falcon…and promising anyone who’d listen that one day he would be a pilot, too, like his daddy.” The dice are the catalyst for Kylo to work through his past resentments towards his father.
The dice’s disappearance is so significant in Star Wars: The Last Jedi because it symbolizes that Han is still with Leia, Luke, and Kylo in spirit. It also signals new and exciting developments in Force abilities that film audiences have not encountered before. Whether Force projections will feature in new Star Wars movies and shows remains to be seen.