Science fiction films depend on world-building to transport their audiences to a place, time, and environment often far removed from what they see everyday. Their immersive quality is why they continue to be such great cinematic experiences, from large franchises like Star Wars to smaller franchises like Blade Runner. This means that action often drives the sci-fi story, so that enough of the fictional world can be seen.
To accomplish this, some actors need to rely on professional stunt performers to make their action sequences look realistic, though they may also prefer it to increase the available jobs on set. Some actors like to eschew the option and handle the stunts themselves, endeavoring to create the most authentic experience for their fans.
Did Their Own Stunts: Tom Cruise
Tom Cruise has made a name for himself in the action world for performing his own stunts in films like Mission Impossible: Fallout, where he suffered a broken ankle for his efforts and delayed the production for almost two months.
Many of those action films have been firmly in the science fiction genre, and he's given his own sweat and blood to titles like Minority Report, Oblivion, Edge of Tomorrow, and War of the Worlds. Whether it's sprinting down streets, participating in high speed chases, or hanging from buildings, he always gives it his all in his stuntwork.
Never Risk It: Will Smith
Will Smith has been a big name in Hollywood for well over two decades, and he's dabbled in every imaginable genre, from comedy and drama, to action and science fiction. Sci-fi is where he got his biggest breakout role in Independence Day, just as The Fresh Prince of Bel-Air was ending in 1996.
Since rocketing to stardom, Smith has shied away from performing his own stunts, especially after the births of his children Willow and Jaden. In films like I Am Legend, After Earth, and most recently Gemini Man, he's used stuntmen like frequent collaborator Travis Parker to make his action sequences look as believable as possible while keeping him safe.
Did Their Own Stunts: Sigourney Weaver
One of the biggest names in science fiction thanks to her appearances in films like Ghostbusters, Avatar, and most importantly Alien, Sigourney Weaver has been known to perform her own stunts even as she's matured.
Recently while filming Avatar 2, to show the world that she's "still got it", the 70-year old Weaver was determined to film all of her underwater sequences herself. She attached weights to herself at the waist and practiced holding her breath for up to six minutes underwater under the expertise of elite former military divers.
Never Risk It: Ryan Reynolds
After making action-packed films like Safe House and The Hitman's Bodyguard, Ryan Reynolds no longer does his own stunts. The Deadpool star, known for playing sci-fi characters who feature in elaborate fight scenes like Hal Jordan in The Green Lantern or Nick Walker in R.I.P.D., no longer takes the risk after suffering multiple injuries.
After making no secret in the press that he'd broken multiple vertebrae, the candor of his team of health professionals was what ultimately made him decide to accept the help of stuntmen.
Did Their Own Stunts: Arnold Schwarzenegger
One of the biggest stars in Hollywood in the '80s and '90s, Arnold Schwarzenegger built his career both before and after his breakout success in Conan the Barbarian by making his body do impressive things. The former Mr. Olympia honed his massive body into a perfect example of aesthetic perfection, and then put it to the test performing his own stunts.
Beginning with Terminator, the Austrian Oak performed his own stunts in all of his science fiction films, including Total Recall, Predator, The Running Man, Eraser, The Sixth Day, and all through the Terminator franchise up to the most recent Terminator: Dark Fate.
Never Risk It: Samuel L. Jackson
Though Samuel L. Jackson is most often associated with tough guy roles, he refrains from anything too physically demanding in his films. Even as Mace Windu in the Star Wars Prequel Trilogy, or as Nick Fury in the sci-fi focused MCU film Captain Marvel, he allowed stuntmen to tackle his more difficult scenes.
The simple reason is that he'd rather give the work to the talented stunt performers, and he knows that if he were to suffer an injury on the set of a film, it would shut down production and dozens of people would be out of jobs.
Did Their Own Stunts: Keanu Reeves
A pillar in the sci-fi community after appearing as Neo in The Matrix Trilogy, news of Keanu Reeves performing his own stunts has been widely circulated. The martial arts he mastered for the films such as ju-jitsu and kung-fu remain part of his daily regiment, and came in handy when he began work on the John Wick franchise.
Reeves has of course appeared in countless other titles in the genre, including Johnny Mnemonic, Replicas, The Day The Earth Stood Still, Chain Reaction, and A Scanner Darkly.
Never Risk It: Sandra Bullock
Sandra Bullock has appeared in a handful of high profile science fiction projects, most notably Gravity, in which she spent time training in zero-gravity simulations with real former astronauts, but declined to perform her own stunts.
Bullock, who learned to drive a bus for Speed and teamed up with Sylvester Stallone in the sci-fi action film Demolition Man has cited that once she became a mother, it wasn't important to do her own stunts. She wanted to be there for her two children, and didn't want to risk them growing up in a world without their mother.
Did Their Own Stunts: Charlize Theron
An actress of many talents, Charlize Theron has blazed a trail for herself by appearing in a variety of films, most notably with science fiction projects appearing on her filmography every few years. She first came to the attention of fans in Aeon Flux back in 2005, and has been gaining more ever since for performing her own stunt work.
In everything from Mad Max: Fury Road to The Old Guard and Prometheus, she proves that hard training, discipline, and the right mindset enables her to become badass characters at peak physical condition, and make her performance as authentic as possible.
Never Risk It: Dwayne Johnson
Though wrestler-turned-superstar Dwayne "The Rock" Johnson is an incredibly gifted athlete, he doesn't perform the majority of his stunts, even in sci-fi films like Doom and G.I. Joe: Retaliation. His reasons for bowing out of stuntwork won't lose him any fans though, because once again Johnson's good-natured approach to his work ethic is genuine.
He's been working with his cousin ever since the early 00's, who became his official stunt double after The Scorpion King. Tanoai Reed even looks like him due to their close family resemblance, which makes the stunts even more believable.