
The space marine, an archetype of military science fiction, is a kind of soldier who operates in outer space or on alien worlds. Historical marines fulfill multiple roles: ship defence, boarding actions, landing parties, and general-purpose high-mobility land deployments that operate within a fixed distance of shore or ship. By analogy, hypothetical space marines would defend allied spaceships, board enemy ships, land on planets and moons, and satisfy rapid-deployment needs throughout space.

Alien, a science-fiction action horror franchise, tells the story of humanity's ongoing encounters with Aliens: a hostile, endoparasitoid, extraterrestrial species. Set between the 21st and 24th centuries over several generations, the film series centers around a character ensemble's struggle for survival against the Aliens and against the greedy, unscrupulous megacorporation Weyland-Yutani.

Clone troopers are fictional characters in the Star Wars franchise created by George Lucas. They have been featured in a number of Star Wars media, including Episode II: Attack of the Clones (2002), Episode III: Revenge of the Sith (2005), The Clone Wars animated film (2008), the related television series of the same name (2008–2020), and the Rebels television series (2014–2018), as well as comics, novels, and video games of the Star Wars Legends expanded universe.

Commander Shepard is the player character in the Mass Effect video game series by BioWare.

Doomguy, also referred to as the Doom Marine and the Doom Slayer is a fictional character from the Doom video game franchise of first-person shooters created by id Software. Introduced as the player character in the 1993 video game Doom, Doomguy is the protagonist of several Doom video games, novelizations, and other media.

Alien, a science-fiction action horror franchise, tells the story of humanity's ongoing encounters with Aliens: a hostile, endoparasitoid, extraterrestrial species. Set between the 21st and 24th centuries over several generations, the film series centers around a character ensemble's struggle for survival against the Aliens and against the greedy, unscrupulous megacorporation Weyland-Yutani.

Corporal Dwayne Hicks is a fictional character in the Alien franchise. First appearing in the film Aliens, who was portrayed by actor Michael Biehn. The character is a Senior Corporal of the United States Colonial Marine Corps aboard the USS Sulaco and is one of the only 4 survivors of the Sulaco crew's expedition to LV-426, along with Ellen Ripley, Rebecca "Newt" Jorden and the android Bishop. Hicks is killed during the introduction of the film's sequel Alien 3, a decision that garnered negative backlash from fans of the franchise. Hicks later returns as the main protagonist of the "Stasis Interrupted" DLC in the videogame Aliens: Colonial Marines., and as a side character in the game's main story.

Private First Class William L. Hudson is a fictional character in the 1986 science fiction movie Aliens, played by actor Bill Paxton. Hudson is a member of the United States Colonial Marines deployed to the planet LV-426 to investigate the loss of communication with a terraforming colony, only to discover that the colony has been overcome with Xenomorphs. The character has become a fan favourite in the Alien franchise, and has been noted as one of Bill Paxton's most iconic and notable roles. The character's quote "Game over man!" has been referenced numerous times in popular culture, and the character has been paid tribute to following Paxton's death in 2017.

Master Chief Petty Officer John-117, or "Master Chief", is a fictional character and the protagonist in the Halo multimedia franchise. Master Chief is a playable character in the series of military science fiction first-person shooter video games Halo: Combat Evolved, Halo 2, Halo 3, Halo 4, Halo 5: Guardians and Halo Infinite. The character also appears in Halo books and graphic novels – including Halo: The Fall of Reach, Halo: The Flood, Halo: First Strike, and Halo: Uprising – and has minor appearances or cameos in other Halo media.

James Eugene Raynor is a fictional character and a major protagonist in Blizzard Entertainment's science fiction StarCraft series. Raynor is a predominant character in the science fiction real-time strategy video games StarCraft and Brood War, and is a player character in StarCraft II: Wings of Liberty. He also appears as a playable character in the crossover multiplayer online battle arena game Heroes of the Storm. Outside video games, Raynor appears in the novels Liberty's Crusade and Queen of Blades, while his backstory is explored in the novels Heaven's Devils and Devil's Due. Robert Clotworthy voices the character in all video game appearances.

Semper Mars: Book One of the Heritage Trilogy is a military science fiction novel by American writer Ian Douglas. It is the first novel in the Heritage Trilogy.

In the fictional universe of Warhammer 40,000, the Space Marines, also known as the Adeptus Astartes, are superhuman warrior-monks who fight for the Imperium of Man. They wear mechanised suits of armor and have modified genomes that grant them superhuman strength and endurance. Some Space Marines have betrayed the Imperium and serve the Gods of Chaos, and are thus known as Chaos Space Marines.

A stormtrooper is a fictional soldier in the Star Wars franchise created by George Lucas. Introduced in Star Wars (1977), the stormtroopers are the elite shock troops/space marines of the Galactic Empire, under the leadership of Emperor Palpatine and his commanders, most notably Darth Vader and Grand Moff Tarkin, during the original film trilogy (1977–1983). The prequel trilogy (1999–2005) establishes their origin as the Galactic Republic's clone troopers, clones of the bounty hunter Jango Fett, used by Supreme Chancellor Palpatine to "win" the Clone Wars and later to take over the government and exterminate the Jedi. Despite this, later stormtroopers are established as recruits; at the time of the original trilogy, only a few stormtroopers are clones, with the only known legion to still contain a significant number of clones being the 501st Legion, aka "Vader's Fist". In the sequel trilogy (2015–2019), the upgraded stormtroopers serve the First Order under the leadership of Supreme Leader Snoke and his commanders, most notably Kylo Ren, General Hux, and Captain Phasma. The final film of the trilogy, The Rise of Skywalker (2019), introduces Sith Troopers, an upgraded variant of the First Order stormtroopers that sport red armor and serve the Sith Eternal, led by a resurrected Emperor Palpatine.

Uchu Sentai Kyuranger is a Japanese tokusatsu drama and the 41st entry of Toei's long-running Super Sentai metaseries, following Doubutsu Sentai Zyuohger. The show premiered on February 12, 2017, joining Kamen Rider Ex-Aid and later Kamen Rider Build in the Super Hero Time line-up on TV Asahi affiliate stations before concluding on February 4, 2018. Kyuranger's primary motifs are constellations and Greco-Roman mythology, and it is also the first Super Sentai series to introduce nine regular members in the beginning instead of five or fewer like previous installments.

Alien, a science-fiction action horror franchise, tells the story of humanity's ongoing encounters with Aliens: a hostile, endoparasitoid, extraterrestrial species. Set between the 21st and 24th centuries over several generations, the film series centers around a character ensemble's struggle for survival against the Aliens and against the greedy, unscrupulous megacorporation Weyland-Yutani.