Narratively, Han Solo’s carbon-freezing makes sense for multiple reasons. In addition to the carbonite making it easier for Boba Fett to deliver him to Jabba the Hutt, it gives Darth Vader a chance to test the carbon-freezing chamber before Luke Skywalker (Mark Hamill) arrives. This way Vader can bring him to the Emperor (Ian McDiarmid) with ease. However, outside of the “Star Wars” canon, there’s a much bigger reason for Solo being turned into a carbonite block that boils down to Harrison Ford’s contract.
Back when the original “Star Wars” hit theaters in 1977, Ford’s contract stated he only had to appear in a single sequel. Thus, when “Star Wars: Episode V – The Empire Strikes Back” premiered, the actor was free of his obligations to the franchise and his character. Still, the folks behind “Empire” were hopeful Ford would return to play Solo one last time, so they chose to put him on ice. This way, if Ford chose not to return for “Star Wars: Episode VI – Return of the Jedi,” the character could be easily written out of the story without being killed.
Whether it’s helping Jedi infiltrate a maximum security prison or giving storytellers an out should their big-name star not return, carbonite has proven incredibly useful.