As a sub-genre of science fiction, sci-fi military books often imagine the future of war, relying heavily on speculative technology and, oftentimes, extraterrestrial combatants. Many authors rely on historical events, such as Hannibal or the Vietnam War, and transcribe them for the future. Instead of nations in conflict, authors present planets at war. The ethics of war and consequences of military action are on the front-lines of many sci-fi military books. When is war justified? What is the value of one life versus many? New moral dilemmas present themselves as science fiction concepts muddle the line between what is and is not permitted. Military science fiction is about the people engrossed by the carnage of war and the larger problems facing them.

Orson Scott Card's Ender's Game is a testament to the influence of military sci-fi novels, attracting both enthusiasts and non-fans of the science fiction genre. In the near future, humanity is threatened by an interstellar war with a mysterious insectoid alien species known as the "buggers." To ensure mankind's survival the military begins training children to mold them into tactical geniuses. Ender, who is considered by many to be one of the greatest sci-fi protagonists, must endure trials, exams, and relationships with fellow students while bearing the weight of humanities future. The novel is powerful for its depiction of an innocent child as he transforms into a ruthless commander. At its core, Ender's Game is a book about humanity and the balancing of survival versus innocence. Do the needs of the many outweigh the needs of one? Card's novel is by far one of the best sci-fi military books, is considered one of the greatest space opera books of all time by many, and the United States Marine Corps includes Ender's Game as part of its professional reading program.

Marko Kloos' Terms of Enlistment is a fast-paced action sci-fi military book about a hard-as-nails drill-sergeant that would find a home in Full Metal Jacket. A looming extraterrestrial menace threatens mankind while the majority of the population lives in poverty. The novel's world is frighteningly dark and its citizens have long lost hope along with all of their possessions. Decrepit conditions convince protagonist Andrew Grayson to enlist in the North American Commonwealth (NAC) military. Departing from the traditions of other classic military sci-fi novels, the militaries of the world in Terms of Enlistment are not united against the alien threat. The NAC is in constant conflict with the Sin-Russian Collective (SRC), who are busy expanding their might into space, as well. Through the eyes of Grayson, the reader learns about the expanding world and experiences brilliant action. Kloos' self-published novel carries on the tradition of classic sci-fi military books.

Author Joe Haldeman provides one of the best examples of the time dilation involved in interstellar travel in The Forever War. Often considered one of the best time travel books, the contemplative story recounting the never-ending conflict between humans and the barely understood Taurans is told by physics student William Mandella. As an elite recruit, Mandella fights on the front lines after competing in a deadly training on the fictional planet of Charon. Traveling light-years to fight the extraterrestrials has massive consequences due to relativity. Upon returning, decades and sometimes centuries have passed on Earth. The impressive novel captures the alienation of a soldier isolated from the rest of civilization by distance and time. The Forever War is often interpreted as an autobiographical account of Haldeman's time in Vietnam written through a space opera filter. The sci-fi military book is an excellent read and Robert Heinlein told Haldeman that it "may be the best future war story I've ever read!"

Old Man's War is John Scalzi's debut novel and is considered one of his best. Capturing the spirit of the grand masters of science fiction, Scalzi incorporates ethical concerns such as life extensions, morality, and identity wrapped in a military conflict. 75-year-old John Perry joins the Colonial Defense Forces (CDF) to use age-reversing technology. Rejuvenated, Perry is shot into space with fellow senior citizens turned young to fight in a bloody interstellar war. Humanity has numerous colonies among the stars. Equipped with enhanced DNA and nanotechnology Perry must fight multiple alien civilizations to secure scarce resources for humanity. Old Man's War is well-written, original, and entertaining literature, avoiding many of the major cliches of military science fiction. Scalzi's novel is consistently ranked as one of the fantasy sci-fi and military books by multiple polls.

The novel almost outright admits clear inspiration from Robert A. Heinlein’s Starship Troopers. Both books follow the process of an individual’s indoctrination to the horrors of war. In the same way, John Scalzi’s novel also draws similarities to The Forever War by John Haldeman. Yet, this is no reason to dismiss this novel as uninspired. While a clear homage to its inspirations, Scalzi’s voice and focus offer an entirely unique perspective in a genre that can often make repetition simple.

The Hugo-award winning Starship Troopers is one of Robert Heinlein's most memorable works, if not the most recognizable thanks to the film of the same name. Considered by many to be the grandfather of military science fiction, Starship Troopers places protagonist Juan "Johnnie" Rico on the front-lines of a war with the arachnoid species "the Bugs." Even though Rico wears high-tech powered armor to battle he is ill-prepared for the onslaught of the relentless bugs. Often considered a dramatization of the American military-industrial complex, Heinlein describes the world he lived in through Starship Troopers. In the middle of the 20th century, war heroes such as Eisenhower and Kennedy were elected President and remained immensely popular. Hence why Heinlein's novel purports that to be a dutiful citizen is to internalize military teachings and aid your country. Heinlein's novel, along with the film, is a must-read for any fan of science-fiction, especially fans of sci-fi military books.

The first book in David Weber’s Honor Harrington series marks the start of a multilayered and action packed story. We follow Commander Harrington, one of the strongest female leads in sci-fi books, and her crew’s expedition around the ever-darkening planet of Medusa, an uncontrolled refuge for criminals and rejects from across the galaxy. But when the crew is made aware of a threat that will destroy Medusa, Commander Harrington finds herself pitted in a conflict between two different ideals in the pursuit of one duty. This series is considered by many to be an essential part of any science fiction library.

The Honor Harrington books are recognized collectively as one of the most successful series in the genre. In a 2011 interview with MilSciFi.com, David Weber was asked about his inspiration behind the series. Weber answered that the initial idea for the book arose out of a conversation with his friend, Jim Baen. Baen asked Weber to propose a series to him, causing him to pitch several different ideas before finally landing on the Honor Harrington universe. In reference to the book’s story and setting, Weber said, "I wanted a framework which would give me a conflict between the kind of open, individualistic political system I admired and the collectivist, state-centered political system I despised, and one which would let me put sympathetic characters into both. I actually started out thinking about using Rome and Carthage for my historical template, but in the end, I decided that the decades of conflict between England and France in the Napoleonic era offered a better one, even though the political systems I'd envisioned weren't perfect fits for either side in the Napoleonic Wars."

Released in 2014, the first book in Pierce Brown’s series has been applauded by many critics as the latest to revolutionize the genre. Placed 700 years after mankind has begun colonization on other planets, the story follows Darrow through a plot of mystery and deception. After being delivered a crushing blow to his personal life, Darrow finds himself fighting for the hearts of minds of humanity against the corrupt upper class. Weaving twists throughout and upsetting the standard structure for science fiction, this series is one that shouldn’t be dismissed as merely up and coming.

Drawing comparisons to Ender’s Game and The Hunger Games, Pierce Brown’s Red Rising series are the newest science fiction books to take the marketplace by storm. Yet, it may come as a surprise that the inspirations for this futuristic story are rooted in writings from the past. In an interview with Goodreads, Pierce Brown spoke about his inspiration for the franchise when he said, "It was really organic. I was hiking in the Cascade Mountain Range, and I'd been rereading the Greek play Antigone. I was struck by the contrast in the story, the dichotomy of the forces represented, a young disenfranchised girl who stands up to cold power, and I thought what a beautiful thing it was that such a fragile character could be a seed of destruction. Then I wondered, What did Antigone leave behind? What if there was a person who was in love with Antigone? How [could] her actions transform not only him but the world? The story started to unravel before me. Eo was conceived far, far ahead of Darrow. She was the first character. It was always about that sacrifice." In the same interview, Pierce Brown added that he was not only inspired by the ancient Greek writings but also was influenced by Alexander Dumas’ classic Count of Monte Cristo and Frank Herbert’s science fiction novel, Dune.

When commanding officer John Geary awakens from a frozen escape pod, he finds himself searching for his place in a war that’s gone one hundred years without him. But after he is given charge over a fleet of ships trapped behind enemy lines, Geary must come to terms with the new ways of war if he wants to take his crew home. The first book in The Lost Fleet series plunges the reader into a six novel saga that examines the dynamics of war’s ever-changing nature. It stands as a modern classic in science fiction that no fan of the genre should allow to slip past the radar.

In an interview with Jean Marie Ward, from Buzzy Mag, Campbell said that his inspiration for this sci-fi military book came when a friend asked him whether it was possible to do a long retreat scenario in Star Trek. He answered no, but Campbell said it got him thinking. "The Anabasis is classic on retreat scenarios, so could I make a situation that fit that? And then I combined that with another thing that I wanted to write about for some time, which was a legend, which exists in many cultures, of a sleeping hero who will someday return when needed." The Lost Fleet was gradually born out of this conversation and Campbell’s interest in the age-old myths of heroes.

Upon its initial release in 1969, critics and readers alike were unable to categorize this satirical novel. Yet, today that remains part of the book’s charm. While mainly centered around the firebombings of Dresden during WWII, the reader follows Billy Pilgrim as he travels through time in a groundbreaking analysis of memory, space, and the wars that have persisted throughout human history. Deemed a monumental achievement in both the science fiction genre as well as classic literature, this sci-fi military book erases and rewrites the standard lines for military science fiction and its personal connection to each of our lives.

This semi-biographical novel takes much of its inspiration from Vonnegut’s service during WWII. In fact, his documentation of the Dresden fire bombings, a central event in the novel, comes almost entirely from his personal experience. While being held in Dresden as a prisoner of war, he survived the Allied bombings by taking refuge in an underground meat locker, an experience referenced in the book’s title, Slaughterhouse Five. After the city’s destruction, Vonnegut and his fellow POW’s spent weeks piling and burning the dead remains, an event that only further ingrained Vonnegut’s ideas on pacifism. Yet, the decision to write the novel only came years after he had returned home. As more information was released on Dresden’s non-militarization as well as the 60,000 civilian casualties that resulted from the bombings, Vonnegut was inspired to create the classic novel we know and love today. The fact that it is rooted in so much truth and realism is what continues to make this book an unforgettable read.

Released in 1965, this science fiction epic was years ahead of its time. Spawning numerous film adaptations, the series remains a massive contribution to the genre. The story chronicles the dangerous struggle over the planet Arrakis, home to one of the most coveted resources in the galaxy. Set within a ruthlessly pragmatic society, where noble households control planets, it seamlessly blends the topics of war, religion, politics, and human nature into an unforgettable masterpiece.

Herbert was initially inspired to write the book after his visit to the Oregon Dunes, but the specific themes developed in the book were greatly inspired by Frank’s experimentation with psychedelic mushrooms. In his book, Mycelium Running: How Mushrooms Can Change the World, Paul Stamets writes, "Frank went on to tell me that much of the premise of Dune—the magic spice (spores) that allowed the bending of space (tripping), the giant worms (maggots digesting mushrooms), the eyes of the Freman (the cerulean blue of Psilocybe mushrooms), the mysticism of the female spiritual warriors, the Bene Gesserits (influenced by tales of Maria Sabina and the sacred mushroom cults of Mexico) —came from his perception of the fungal life cycle, and his imagination was stimulated by his experiences with the use of magic mushrooms."

Steakley’s series chronicles the story of mankind’s war against an alien race and a research colony on the outskirts of civilization. The novel masterfully fuses these two subplots into an unforgettable story that serves as a psychological and moral examination of man under the horrors of war. Published in 1984, the sci-fi military book draws similarities to Robert A. Heinlein’s classic novel, Starship Troopers, but still dives headfirst into a unique take on its predecessors and the science fiction genre as whole.

Titled after Rudyard Kipling’s poem Hymn Before Action, the first book in John Ringo’s Legacy of the Aldenata series is heralded as a crowning achievement in sci-fi military books. After Earth is warned by an alien race, The Galactics, of an oncoming invasion by other extraterrestrials, mankind is caught up in a whirlwind to save Earth. But after The Galactics outline their controversial demands in return for assisting Earth, it is difficult to know who is the real enemy.

Robert A. Heinlein, the famous author of Starship Troopers, described The Mote in God’s Eye as, "Possibly the finest science fiction novel I have ever read." Decades after its original publication in 1974, those words still resound clear and true in the minds of science fiction readers across the genre. Set in the year AD 3017, the book tells the story of mankind’s first contact with an alien species in the aftermath of an interstellar civil war. Analyzing humanity’s place in the future and the greatest threats to its ideals, the book remains a classic in every right. This is an essential piece to any reader’s collection.

First serialized in 1897, the novel has acted as an inspirational foundation to dozens of writers in the genre. Stylistically, the novel is presented by the unnamed narrator as a factual account of the Martian invasion. This technique immerses the reader into a startlingly real struggle between mankind and extraterrestrials. With anything but a straightforward interpretation, H.G. Well’s work has been heralded as not only a classic invasion story, but also a social commentary upon British imperialism and evolutionary theory.

There were two events that served as the inspiration for Wells’ science fiction classic War of the Worlds. Both of them come as a result of Britain’s advancement and power within those years. 1894 served as the year of exploration. The first groundbreaking observations of Mars were influential to Wells and other writers of the time, but one instance, in particular, is referenced as sparking the idea for the novel’s plot. Italian astronomer Giovanni Schiaparelli, had reported seeing "channels" on the red planet, but his writing was misinterpreted as "canals." This slightly humorous mistake sent the public into a frenzy, but for Wells, this possibility of life on Mars planted the idea for War of the Worlds. The second inspiration was Wells’ famous criticism of British Imperialism. Part of the novel’s purpose is to paint a hypothetical for the British people: what if Britain was invaded? Wells was inspired by the possibilities of alien life and his book testifies to the fact that he didn’t wish to keep those big questions to himself.

Keji Kiriya, a new recruit, is deployed on his first mission in the war against the mysterious Mimics. But after dying at the hands of the Mimics, Keji is caught in a time loop, forever reliving his fateful battle. Exploring the themes of destiny and honor, the story follows this new recruit as he fights to grow his skills and change this seemingly endless cycle. The novel is considered a breakthrough in the sci-fi military book genre, heralded as a classic by a number of names in science fiction. This gripping analysis of death and resurrection is an unforgettable reading experience.

This 1979 collection of short stories has been an innovative and integral part of the genre’s progression. Documenting the struggles and triumphs of a mercenary tank regime called Hammer’s Slammers. Author David Drake intermixes realism and legend by founding the novels on his past service with the 11th Armored Cavalry Regiment in Vietnam and Cambodia, as well as paralleling Homer’s Odyssey in one story. By outlining an entirely immersive universe and introducing an array of characters, audiences have been captivated into reading these timeless short stories one after the other.

Considered one of the "Big Three" for science fiction writers along with Arthur C. Clarke and Isaac Asimov, Robert A. Heinlein paints a unique and compelling story that fans of the genre would be wrong to ignore. The story follows the lunar colony’s revolt against its rule from Earth and the expected struggle of these two forces. The book was nominated for the Nebula award in 1966 and skillfully handles themes of libertarianism, colonization, and its place in the future. Robert A. Heinlein and his books hold a permanent place in the military science fiction genre for their timeless storytelling.