Star Wars: The Force Awakens director JJ Abrams said that it had been his intention from the start that a woman should be at the centre of the film.

Speaking to journalists at a press conference following The Force Awakens’ European premiere, Abrams said: “From the beginning of discussions [with writer Lawrence Kasdan]. the notion of a woman at the centre of the story was always something that was compelling and exciting to me. And not just at the centre. We knew that, in addition to Leia who was a critical piece of this puzzle, we wanted to have other women – not necessarily human, but female – characters in the story.”

The Guardian film show special: Star Wars: The Force Awakens Guardian

“We have Lupita [Nyong’o] playing Maz Kanata, who is the voice of Force wisdom in the story and Phasma leading the evil side of the stormtroopers; we wanted to have female stormtroopers, and pilots, which we did. We just wanted to make thing this thing not feel like it was not inclusive.”

“We always wanted to write Rey as the central character, but it was just one of the things we knew we wanted to do: to make the film look and feel more like the way the world looks and feels.”

Lupita Nyong’o plays Maz Kanata, ‘the voice of Force wisdom’ in Star Wars: The Force Awakens. Photograph: Facundo Arrizabalaga/EPA

As to the vexed issue of “spoiler jihad” and Philadelphia police’s suggestion that spoilers should me made illegal, Abrams said it was “no surprise” that some internet users had been giving away key plot details, but Harrison Ford thanked the media for adhering to the film-maker’s requests that as little as possible should be revealed. Ford said: “I am amazed by the way the press has respected their readership in this regard, and has not spilled the beans. We are all very grateful.”

However, as has been the case at previous promotional events, the presence of Carrie Fisher has considerably enlivened proceedings. When asked what advice she had given the younger actors who were newcomers to the Star Wars franchise she replied: “Don’t go through the crew like wildfire.” Another questioner asked what were the strangest Star Wars merchandising items they had seen, and Fisher said: “Shampoo bottle, because you can twist off your head” – before pointing out a Princess Leia strain of marijuana was available. “Not from me – but I have friends!” More comedy was provided by the late arrival of actor John Boyega, who apologised for oversleeping and blamed a “very busy night”.

Star Wars fans geek out at London premiere of The Force Awakens Guardian

Fisher also positively contrasted the experience of working with Abrams with that of the original’s director George Lucas. She said: “George was wonderful but he never spoke. I mean, he just said ‘Faster’ and ‘More intense’. But [JJ] talks a lot ... and he has a lot of energy. We didn’t have any energy on the first film. It was sad. Right?” Ford, in emphatic tones, agreed: “Exactly right.” Fisher raised another laugh by saying Abrams “really loved making the movie, except with me”.

Ford continued with his implied criticism of Lucas’ creative skills – of which he has well-documented disdain – by saying: “I have actually relished this entire experience in a way I had not anticipated.” He continued: “A lot of the credit goes to JJ and Larry [Kasdan] – this is a rare experience in my old life.”

Ford also said that he had no involvement whatsoever in the projected Star Wars spin-off featuring a young Han Solo. “I don’t know what to think about that. I am glad someone else will have the burden of being young, it’s well beyond my understanding or control, and I of course want nothing to do with it, in the nicest possible way.”

The closest the session got to any remotely controversial topic was about the film production’s presence on the remote Irish islet of Skellig Michael, which had aroused considerable protest over its protected status as a Unesco world heritage site. Saying he “couldn’t believe they let us shoot there”, Abrams added that on the first day of their three-day shoot there were huge numbers of puffins on the islet, but that they had all disappeared the next day. “It was very strange; apparently it was the last day before they all fly away.”