Mark Hamill and Rian Johnson revealed at a BAFTA screening that Hamill asked to play a CG character in addition to his role as Luke Skywalker, saying that he had done it before (he had previously done CGI work for the computer game Squadron 42 (2026) (which is the separate solo campaign of Star Citizen)). In the film he plays Dobbu Scay, the character who puts money inside BB-8 in the Casino scenes.
After reading the script for the first time, Mark Hamill told writer/director Rian Johnson, "I pretty much fundamentally disagree with every choice you've made for this character. Now having said that, I have gotten it off my chest, and my job now is to take what you've created and do my best to realize your vision". He was surprised by the changes that Johnson made to Luke Skywalker. In order to get into the mindset of an old and weary Luke, Hamill wrote a personal backstory for the character.
After first completing the arduous 600-foot climb on Ireland's Skellig Michael island, Mark Hamill had hoped that he could avoid having to repeat the trek for additional scenes if he could somehow remain on the summit overnight, thus forfeiting the luxury of room service at his hotel. He suggested sleeping in a tent and 'staying in character.' However, after some inquiries were made with the Irish authorities, he was told by producer Kathleen Kennedy that he was not permitted to pitch a tent because the location is a protected UNESCO World Heritage Site.
With the passing of Kenny Baker, Anthony Daniels is now the only remaining actor to appear in all the official Star Wars films.
Prince William of Wales: On a visit to Pinewood Studios with his brother Harry, both Star Wars fans, the British prince was given a cameo as a Storm Trooper.
Gary Barlow: One of the extras in the trenches on Crait was the lead singer of the 1990s pop group Take That.
Prince Harry: On a visit to Pinewood Studios with his brother William, both Star Wars fans, the British prince was given a cameo as a Storm Trooper.
Nathan Johnson: One of the two men in the cell behind Finn and Rose is Rian Johnson's cousin, a film composer.
Rian Johnson: The voice of the alien on the Canto Bight yacht. His hand is also used as an insert when Luke Skywalker pulls the dice off the Millennium Falcon.