Half a century ago, Hollywood was at a crossroads. The major studios were in the doldrums, haemorrhaging money on bloated star vehicles such as Paint Your Wagon that were relics from a different era. Iconoclastic social critiques such as Bonnie and Clyde and Easy Rider were generating headlines and queues around the block. No one knew what the public wanted next. All bets were off. “There was a brief window where someone could go into a studio and propose any film,” explains Simon McBurney, the 59-year-old actor and artistic director of groundbreaking theatre company Complicite, when we meet in an east London cafe.

He sounds so excited by this notion that he would surely be rubbing his hands with glee if his right thumb were not swaddled in a cartoonishly large bandage, the sort that Tom might wear after Jerry has thwacked his paw with a mallet. It was an accident while cleaning the blender: “I didn’t realise it was plugged in. It took a piece out of my thumb the size of a sugar lump.” I wince in sympathy but he looks blankly at me from beneath the brim of his canvas cap. He is too caught up in thinking about that Hollywood revolution to worry about a sore thumb. One Flew Over the Cuckoo’s Nest was for him the clinching film from the American new wave of the late 1960s into the 1970s. “As an actor, that was the absolute explosion for me,” he says.

McBurney is steeped in the era and its social and cultural impact again now that he is directing an adaptation of The Kid Stays in the Picture, the scandalous, hard-boiled show-business memoir by producer Robert Evans, who transformed the industry when he became head of production at Paramount. In shepherding to the screen hits including Rosemary’s Baby, The Godfather and Chinatown, he took the studio from ninth place (of nine) to No 1.

Facebook Twitter Pinterest ‘In a moment you’ll ask me another question and I’ll tell you some other lie’ … Simon McBurney. Photograph: David Levene/The Guardian

The dynamic and silver-tongued Evans, who is 86 and still has an office on the Paramount lot, was a former actor who became a millionaire in his 20s after selling the women’s clothing business he had started with his brother. (He liked to say he was “in women’s pants”.) He described himself as a “half-assed” actor but what he knew about was story. In the second half of the 1960s he snapped up the rights to novels including The Detective and The Godfather (when it was still titled Mafia and amounted to a pile of “rumpled pages”), which he transformed into modestly budgeted mega-hits. He also mastered cross-platforming long before that term was coined: the publisher of Love Story didn’t have much faith in that tearjerker but Evans put $25,000 toward expanding its print run when he bought the film rights. He then nurtured relationships among media subsidiaries of Paramount’s parent company, Gulf+Western, to guarantee the success of the book, which in turn boosted the movie version.

He was a gambler, to be sure, and the gambles didn’t always pay off. Towards the end of the 1970s, he was deeply in debt and addicted to cocaine; in the 80s he was briefly a murder suspect after the death of a potential investor in his film The Cotton Club (a spectacular flop). But he was also a visionary. He changed the movies for ever, and for the better – it was he who ordered Francis Ford Coppola to add nearly an hour to The Godfather after the director turned in an initial cut that resembled, in Evans’s words, “a long, bad trailer for a really good film”.

“What he understood,” says McBurney, “was ‘fuck stars, fuck distribution’. What’s key is story. He worked out that if you get the right story, everybody will go. The more truthful that story is, the more not on the money but slightly ahead of the money, the more it will key into the zeitgeist. People had begun to understand through television that there were some shit things going on in the world and they wanted a degree of that reality.”

Facebook Twitter Pinterest Clint Dyer and Danny Huston in rehearsals for The Kid Stays in the Picture. Photograph: Sarah Ainslie/Royal Court

One of the elements that interests McBurney in Evans’s memoir is the overlap between art and life. The preface to The Kid Stays in the Picture memorably begins: “There are three sides to every story: yours … mine … and the truth. No one is lying.” McBurney smiles at that. “The whole question of what is and isn’t true is a fascinating one. People say, ‘But is it a real story?’ Well, all stories are real because they all really do something, they all really engage you. When I told you about my thumb you bought into it because it’s a good story. I can make it less good – ‘It’s fine, it’s just a little cut’ – but I choose to embellish because I enjoy telling stories.” This extends even to the nature of our conversation. “In a moment you’ll ask me another question and I’ll tell you some other lie.” He smiles faintly and takes a chomp on his sandwich.

The distinction between fact and fiction is particularly irrelevant in the case of Evans because of the bizarre hall-of-mirrors effect created by his films. After Love Story was released, the rate of impregnation suddenly shot up. When The Godfather opened, it became the favourite film of the mafia, who then began to dress like the characters in the film. “There is this extraordinary interplay in 20th-century American culture,” says McBurney, “between who people are and who they imagine they are. Look at America now. Everything is corrupt. Everything is done on the fly, with a degree of improvisation. There is the surface where you have the myth and the magic, but underneath it’s extremely murky. As Evans said to Henry Kissinger, politics is only second-rate show business. Which then of course becomes true with the election of Ronald Reagan. And Kissinger, coming out of The Godfather, says: “It’s just like Washington but with different faces.’”

No one familiar with Complicite’s work would expect a “straight” adaptation of the book. It seems McBurney is planning to use Evans’s story as a prism through which to view the US. “Kind of,” he says with a slight grimace. “I’m not hijacking the story. What interests me is the way that something is real and not real, happening and not happening. There’s a story about it and yet the story is the reality.”

Facebook Twitter Pinterest Marlon Brando in The Godfather (1972). Photograph: Allstar/Paramount

The creative process behind any McBurney production can appear precarious to outsiders: A Disappearing Number, Complicite’s show about the mathematician Srinivasa Ramanujan, was first staged in 2007 in an incomplete form, and there was still no script for The Encounter 10 days before its premiere in 2015. I can vouch that a script exists for The Kid Stays in the Picture – it occupies the seat beside its author while we talk – but the details are still up in the air. There are unlikely to be any clips from Evans’s movies. “That would just make you want to see the rest of the film.” McBurney will admit that there is currently a live camera feed in the show. “Whether there will be finally I don’t know.” The actor Danny Huston (whose father, John, was unforgettably sinister as Noah Cross in Chinatown) has been cast in the show but there is a rumour that the role of Evans will be divided among multiple performers, à la Todd Haynes’s Dylan film I’m Not There – or, indeed, Beware of Pity, Complicite’s recent Stefan Zweig adaptation.

I’ve been incredibly lonely there. It’s so nebulous and yet it’s easy, in spite of its vastness, to feel closed-in Simon McBurney on Los Angeles

Of course, there is only one Robert Evans. When I call him at his home in Los Angeles, he is in good spirits. His words sometimes come haltingly – he suffered a series of strokes in the late 1990s – but the charm is intact and impressive. As is that deep, rich voice, both gravelly and sweet. I ask what makes a good producer and he gives a wheezing laugh. “That’s a good question. Every success I’ve had has been for a different reason and every failure for the same one – I said ‘yes’ when I meant ‘no’. With very few exceptions, that’s been the story of my life. Darryl Zanuck told me, ‘If you can introduce your movie in a paragraph you’ll make it a hit. If you can do it in a sentence, you’ve got yourself a blockbuster.’ He was 5ft 4.” Height is clearly an important factor here, so I ask Evans how tall he is. “5ft 10!” he says with relish. He has the knack of making well-worn stories sound as though they’ve just popped into his head. The next moment, he will ambush you with a poignant reflection. “I’m still alive. A little battered. But I like myself. For not selling out. There are people who have bigger homes, bigger boats. I don’t care about that. No one has bigger dreams.”

I wonder what he sees when he looks around Hollywood today. “Young people,” he shoots back without missing a beat. “However. I’m not into machines. I’m not into Mars. I like feelings. How does it feel? That, to me, is the turn-on. And story. If it ain’t on the page, it ain’t on the screen, or anywhere else.” McBurney concurs: “The studios now will only fund something if they know it’s going to make money – if it’s superhero X, Y or Z, and it did well the first time, then they’ll make a second or third.” Or, for that matter, a fifth. After all, McBurney himself starred in the most recent instalment of – but no, he’s already beaten me to the punch. “I know, I did Mission: Impossible,” he says, turning away from me. “I don’t know whether to say ‘Shame on me’ or not. The fact is I have a family, and every now and then I go, ‘Well, I’d better pay for some trousers now.’”

His own brushes with Hollywood have been few and far between but he did briefly approach Coppola’s orbit in the early 1990s, when he was flown out to audition to play Renfield in the director’s adaptation of Dracula. “I spent two weeks in Los Angeles drifting in and out of castings and meetings. Coppola at that point was very heavily protected by his own coterie of people at Zoetrope and reportedly never got to see my tape – but, hey, I lost out to Tom Waits.”

Facebook Twitter Pinterest Robert Evans with his former wife Ali MacGraw. Photograph: Allstar/USA films

His experience of LA and the film industry is largely typical. “I stayed in the house of a producer friend who then gave me keys to someone else’s house where the Beatles had stayed. All very bizarre. We were let in, no one was there. My girlfriend and I swam up and down in the swimming pool, wandered around stark naked, drove up to Big Sur. It was kind of crazy. The sense of impermanence, the lack of specificity can, if you are in the least bit sensitive or emotionally unstable, be disturbing. I’ve been incredibly lonely there. It’s so nebulous and yet it’s easy, in spite of its vastness, to feel closed-in.”

McBurney has often said he makes things so that he can understand them, and The Kid Stays in the Picture is no exception. “I don’t know about Hollywood and this world and I find a lot of it distasteful. And yet meeting Robert and reading the book there is something fascinating and human about this story of a man who goes right to the top, which in that profession means right to the top of America.”

McBurney and Evans seem like unlikely bedfellows but both men emphasise their points of overlap. When no one could fathom Robert Towne’s Chinatown screenplay, McBurney points out, “Evans made it, in a sense, in order to understand it.” The producer chuckles at the memory: “Everyone thought it was written in Chinese!” Though he has met McBurney only once, he thinks they might be kindred spirits. “His reputation precedes him,” he says admiringly. “I’ve been told by many people he’s a genius. He is an actor and a writer and he’s been around a long time. He’s his own man.” Sounds familiar, I say. He lets out a laugh like a bowling ball rolling down an alley. “That’s my type o’ guy.”

• The Kid Stays in the Picture is at the Royal Court, London SW1, from 7 March to 8 April.