Science fiction is often a medium concerned with taking concepts from other genres of fiction and shifting them into a new location to see what changes. One of the favorite topics of sci-fi authors is the future of combat. Since guns are the weapons of the modern day, it stands to reason that they'll be the mainstay of the future as well.
The weapon of choice in a work of fiction informs its unique action. Dune wouldn't be what it is today without its stellar knife combat scenes. Star Wars is packed with laser weaponry, but the lightsaber is its favorite armament. Other sci-fi stories take a grittier route and choose the gun.
The Lobby - The Matrix (1999)
Realism is a fun tool when it comes to shootout scenes. It's not a binary, it's a slider with a million different points. The Wachowskis' seminal work of cyberpunk fiction features some of the most influential action scenes in cinematic history. It's one of those films that's weird to watch in the modern era because everything that's come out since its release has taken ideas from it. There are plenty of kung fu battles and unique fight scenes that make up the film's iconic action tapestry, but none more gripping than the lobby shootout. Neo and Trinity making their way through the metal detectors, only to reveal their hip-mounted arsenal and waste a room of cops is one of the best opening beats of an action scene, and it just builds from there. It's one of the best scenes in sci-fi history, and it makes great use of the film's unique dream-like world.
The Assault on the MNU - District 9 (2009)
Neil Blomkamp's directorial debut received praise for a number of well-executed aspects, landing it among the best-received sci-fi films of the modern era. Its grim social commentary, brilliant technical detail, and emotionally gutting storyline made it a stellar work of grounded science fiction. Its action scenes weren't the first point of praise for any of its fans, but they were still excellent. The film takes place in Johannesburg which acts as an apartheid state with a newfound alien species. Sharlto Copley's Wikus is a Multinational United operative who finds himself unexpectedly granted an alien mutation. Suddenly able to wield alien weaponry, Wikus joins well-meaning alien Christopher Johnson for an attack on his former employers' base. It's a tense and powerful action scene, made all the more unnerving for what Wikus and Chris find within.
Breaking the code - The Mandalorian (2019)
Though the Star Wars franchise usually prefers to deliver its central action scenes through the medium of saber duels, The Mandalorian features some of the best blaster combat in sci-fi history. There are too many great shootouts to choose from, but one of the earliest entries in its ongoing tale features a perfect escalating combat scene. This comes in Chapter 3: "The Sin", in which Mando decides to break the rules of the Bounty Hunter's Guild in favor of protecting The Child. This puts him in conflict with Greef Karga and his army of bounty hunters. He's forced to shoot his way out against countless enemy shooters. He makes use of a hovering cart as a hiding place, reduces enemies to dust with his powerful rifle, and sprays his flamethrower wildly. It's a desperate struggle against impossible odds until an army of fellow Mandalorians appear to turn the tides. It even ends with a quick draw duel against Karga. It's one of the best battles of this excellent show, and it remains to be seen if the upcoming third season will top it.
Starting a Revolution - Equilibrium (2002)
This underrated dystopian sci-fi action film features some of the most unique gunplay on the silver screen. The film takes place in a world that's under the heel of a dictatorial regime that keeps the populace in line with an emotion-suppressing drug. Christian Bale stars as John Preston, an enforcer who, through a twist of fate, finds himself turning against his ideology. As a result, he uses his incredible combat skills against his former peers. Near the final scene, Preston is captured by his fellow warriors and must shoot his way out of capture and into close quarters with the dictator. It's a strange and powerful shootout that makes full use of the underrated film's gimmicks.
"Human Casualties: 0.0" - Terminator 2: Judgement Day (1991)
As everyone knows, T2 is one of the strongest sci-fi action movies ever made. Though the opening scene depicting the nightmarish future war between man and machine is often highly praised, there are plenty of great gunfights packed in. During the scene in which Miles Dyson and John Connor attempt to change the future, the T-800 busies himself dealing with the massive police army that waits outside. The T-800 has been explicitly ordered never to take another human life, but he still takes to the window with a minigun and a grenade launcher. Watching him unleash his potential against a massive army and defeat the entire police force without a single casualty is a gripping showcase of what the T-800 is truly capable of. Sometimes, all fans need is a great set and some heavy munitions.