John McTiernan on 35 years of Predator: 'We were like 14-year-old boys, turned loose in the fairytale shop'

McTiernan will revisit Predator as part of the inaugural London Action Festival, taking to the stage for a Q&A following a screening of the movie on Sunday 31st July at London's Picturehouse Central.

Legend has it that the film's concept originated as a joke pitch for a new Rocky movie – having vanquished all Earthly opponents, Sylvester Stallone's nemesis in the next sequel would have to be an aggressive extraterrestrial. Screenwriting duo Jim and John Thomas took the gag and ran with it, drafting a script – originally titled Hunter – that pitched a formidable alien huntsman against a human combat soldier.

For McTiernan, the outrageousness of the film's premise was part of its appeal – he once described Predator as "the movie that the-14 year-old boy wants to see".

"You had a 14-year-old boy making it – me!" he tells RadioTimes.com, grinning. "It was clear that was where the heart of the movie should be."

For the lead role of Dutch, the one man capable of facing down the Predator, producers Joel Silver and Lawrence Gordon approached Arnold Schwarzenegger, still in the early days of his action movie career with 1985's Commando and 1986's Raw Deal his most notable credits following breakthrough roles in 1982's Conan the Barbarian and 1984's The Terminator.

Schwarzenegger was then surrounded by an eclectic ensemble to play Dutch's military rescue team, including professional wrestler Jesse Ventura, character actor (and Schwarzenegger's Commando co-star) Bill Duke and Rocky series veteran Carl Weathers.

"Joel Silver had a wonderful casting director who came up with wild, crazy people like Jesse Ventura – my contribution was usually the more actor-ish people," McTiernan recalls. "I wanted Bill Duke because I thought he was a fabulous actor.

"I just tried to set a tone where there was enough good acting going on that Arnold would copy. And he did. Because Arnold has always been hugely competitive. I just tried to set a tone like that and he on his own, out of his own natural sense of competition, just joined in."

The casting of Weathers as Dillon – a CIA operative with a hidden agenda who shares a number of intense, close-quarters scenes with his former friend Dutch – was in particular designed "to give Arnold the chance to react to what was thrown to him – and to try to keep up with Carl."

McTiernan explains: "What normally happens when a star is not in a scene and somebody else is shooting, they disappear back in their trailer… when Carl was working, Arnold was at the edge of the set, watching, which was what I'd hoped for. And it worked."

One week before principal photography was scheduled to start, McTiernan had the cast travel to Mexico for a week of training with Gary Goldman, a former military officer and technical adviser on the film – though he insists this was more an exercise in male bonding than anything else. "Gary got all the guys in something like uniforms and staged hikes so that by the time they started shooting the movie they knew each other to some extent, because they'd spent a week walking in the jungle, getting sweaty and filthy and covered with insects.

"That was mostly what the military adviser did – it wasn't about how to make the thing accurate, because it was never going to be."

Even disregarding the film's extraterrestrial elements, the more grounded aspects of Predator's production – including its portrayal of military combat – were again shaped by the same 'teenage boy' ethos. "Guns were a giant part of it," McTiernan recalls. "We went to the armourer and they showed us all these guns and I started, like a 14-year-old, mixing and matching.

"We made up several guns, like Old Painless [the handheld M134 Minigun used by Ventura's tough-talking soldier Blain Cooper] – that's supposed to be mounted on a helicopter, it was never supposed to be carried by a man – and there was a thing with 40mm grenades and we had them build a giant revolver out of it… that sort of stuff was all very childish."

Perhaps the peak of the film's adolescent glee arrives halfway through, in a sequence that sees Schwarzenegger and his squad respond to the death of one of their number by unleashing their formidable arsenal of weapons, flattening a sizeable patch of jungle. The scene lasts a full minute.

"There was a studio executive who kept giving me s**t that I wasn't doing enough shots of the barrels of guns – he wanted gun pornography, it was terrible," McTiernan says. "Finally I got mad and I said, 'Alright, I will give you a gun scene that ends all gun scenes. I will give you so much gun pornography that you just don't need anymore.'

"So I invented that scene. 'Okay, guys, we're going to spend five minutes where we do nothing except blaze away with stupid guns.' So you can't possibly think of a movie that has more guns in it than that."

McTiernan got the last laugh, however, memorably undermining the mindless machismo by having Richard Chaves's character Poncho inspect the chaos and tell his team that they failed to fell a single opponent. "The first thing that happens immediately after is the character comes in and says, 'we hit nothing'."

Predator sees the titular monster pick off more and more of Dutch's team until only Schwarzenegger's character is left standing, building to a climactic showdown between man and beast. It's not until this point in the movie that the Predator's face is finally revealed – an iconic piece of creature design by legendary special make-up effects creator Stan Winston, who was recommended by Schwarzenegger (with whom he'd previously collaborated on The Terminator) after earlier attempts to realise the creature had failed to prove sufficiently scary.

The final product by Winston is still incredibly effective three-and-a-half decades on, with McTiernan a big proponent for the use of practical effects work over computer-generated VFX. "As soon as the audience knows that it's a computer-generated effect, you're in storybook land. It's not a movie anymore. It's no longer real to them. The audience drops out. So while I've always used some computer effects, I tried to hide them."

He references a sequence in 1995's Die Hard with a Vengeance, which used digital VFX to enhance a car crash sequence that was shot for real with an additional vehicle inserted to up the peril.

"90 per cent of the picture is real for the audience. But when you start out to make a whole thing that's completely fantastic, then you wind up with something that's completely fantastic – and unbelievable. But it’s dependable for the larger studios and that model of filmmaking where 70% of the investment in the film is marketing. It fits in that model. And it works just fine."

After a brutal bout in which he's physically outmatched, Dutch is – spoiler alert – able to use his wits rather than his brawn to vanquish the Predator. But it's a bittersweet victory; in the end, he stands alone, his entire team gone.

McTiernan felt this downbeat ending wasn't quite the right note on which to end such a rollercoaster ride of a movie, kicking off the end credits with a tongue-in-cheek montage which sees the various members of the cast break character to variously salute, wink and smile at the audience.

"It lifted the whole thing at the end of the movie," McTiernan says. "It was just a wonderful, old fashioned, theatrical, funny thing to do. We just did it because it was fun. We were a bunch of 14 year olds who got turned loose in the fairytale shop."

Predator's 35th anniversary screening with a Q&A from director John McTiernan takes place on Sunday, 31st July at 9:30am at Picturehouse Central, London, as part of The London Action Festival. Buy tickets now.

Check out more of our Film coverage or visit our TV Guide to see what's on tonight.

The latest issue of Radio Times magazine is on sale now – subscribe now and get the next 12 issues for only £1. For more from the biggest stars in TV, listen to the Radio Times podcast with Jane Garvey.