The star will reprise his role as Luke Skywalker in The Force Awakens sequel, which is slated to hit theatres in 2017, and, like other releases in the franchise, he reveals he is contractually forbidden from divulging anything about the movie.

"It can be annoying and intrusive," he says. "You get call sheets, there's no names, everybody's got a number! You're number 11. You're 33. You're looking at the call sheets wondering who's working today, and it's like, 'Oh, I loved 22's work. She's twice as good as 11.'"

Hamill admits his advancing age has also made it more difficult to remember his lines as castmembers are banned from taking scripts home.

"I understand why they're doing it, but it can get really out of control with the pages that get shredded every day," he continues. "I'm in the elderly recluse stage of my career, I have to write cartoons in the margins to make me remember these lines. Need a script you can write on and take home and look and read! So they let me have one scene, and I keep it on my person."

Hamill's fellow franchise veteran Carrie Fisher and The Force Awaken stars Daisy Ridley and Oscar Isaac will also return for the highly-anticipated Episode VIII.