The newest film in the Star Wars saga presented many obstacles for the heroes of the Resistance, but it also presented offered challenges for the actors.
"Well I, like Mark [Hamill], had some reservations about the script," Ridley said. "I thought, 'Where is John [Boyega]? He's away from me, and I don't want to be away from him.'" Her response prompted laughs from the audience.
In The Force Awakens, fans were introduced to Rey and Finn who underwent an epic journey together, but after separating at the end of the film they don't reunite until the closing moments of The Last Jedi.
"Getting into something like this is pretty overwhelming, and John was my guy the whole way through filming and press stuff [on The Force Awakens], and it was scary. It was really scary thinking about the next chapter with us apart. And I expressed that to Rian.
"Luckily we had a couple weeks to rehearse and we talked everything through. And, obviously, it's an ongoing conversation as we went. But I found it quite difficult, I remember saying to Rian I felt much more neurotic this time."
Hamill also spoke about how he wasn't sure he nailed his character or performance when filming certain scenes, though Johnson would assure him that he had good takes when they would move on. Ridley also expressed similar experiences.
"There were times where I thought, I don't think I've done the right thing, but Rian, if you're happy, I'm happy. Because I think it's that thing of being pushed and going somewhere where you can't quite figure it out, and [Rey's] figuring it out at the same time. But you do sort of think, I don't know if I'm doing this justice."
Hamill chimed in that Johnson pushed the actors out of their comfort zones, prompting great performances from the cast of the film.
Star Wars: The Last Jedi is now playing in theaters.