Books Like Old Man's War: 10 Military Sci-Fi Reads to Try Next
A 75-year-old widower walks away from his wife's grave and into a recruiting office, and that is the least strange thing that happens to him. John Perry's decision is the hook of John Scalzi's Old Man's War, and it explains why finding books like Old Man's War is harder than it sounds. Readers come for two things, usually at once: a bargain that looks fair on paper and costs far more than the brochure admits, and a narrator who stays funny, quick, and good company while he finds out.
Those two appeals pull in different directions when you go shopping for a readalike. A book can match the first completely and miss the second, which is how a reader who wanted more of Perry's wit ends up with a very serious novel about war and loss. This list sorts ten military sci-fi reads by what hooked you, and each entry says how its tone compares with Scalzi's.
Every pick is military science fiction in the usual sense: the story stays close to the people serving and fighting. If you want war used mainly to expose empires and institutions, that is a neighboring shelf, and the site’s guide to military space opera covers it.
What Is Military Science Fiction?
Military science fiction is science fiction in which soldiers, military units, and the experience of combat drive the story.
The setting can be a starship fleet, a tank regiment, or an infantry platoon on an alien world. What defines the subgenre is the point of view: the story follows people inside a military structure and asks what that structure does to them. It overlaps with space opera, and the line between them is not absolute. One practical way I tell them apart is to ask where the narrative places its weight. Military science fiction tends to stay closest to the people serving and fighting. Military space opera more often widens the lens to governments, civilizations, and the political consequences of war. A rough check I use is to remove the war and see what is left. It is a reading aid, not a rule, and the space opera guide covers the broader genre boundary.
Why Old Man's War Works (and Why Most Readalikes Miss It)
Scalzi's debut began life online. He serialized it on his blog one chapter a day in December 2002, and Tor editor Patrick Nielsen Hayden noticed it there. Tor published it in January 2005. It was a finalist for the 2006 Hugo Award for Best Novel, Scalzi won the John W. Campbell Award for Best New Writer that same year, and in 2026 the whole Old Man's War series won the Hugo Award for Best Series.
Scalzi has said he was inspired by Robert Heinlein's Starship Troopers, and by his own account he picked military science fiction partly because he thought it would sell. That detail is more interesting than it sounds. It means Old Man's War was built on purpose as a conversation with a famous book.
The first appeal is the contract. Military science fiction is usually a young person's story: a recruit, a draftee, a cadet. Old Man's War inverts that. Its recruits are old, and what they carry into the barracks is grief and a lifetime of habits, not youthful ambition. The Colonial Defense Forces tell Perry the terms: leave Earth for good, serve your years, and receive a new body and a chance at a home. The tension is the distance between those terms and what the war actually asks.
The second appeal is the voice, and it is the one readalike lists skip. Perry narrates in the first person, with a dry sense of humor, brisk pacing, and real warmth between the characters. Big ideas arrive in plain language, which is why the book is so often recommended to people new to science fiction. Plenty of readers love it mainly for that reason. If you are one of them, the most serious books on this list will disappoint you, so read the tone notes before you commit.
10 Books Like Old Man's War, Sorted by What You Loved
A close thematic match is not always a close tonal match. The Forever War shares Scalzi's interest in what military service takes away, but it is colder and more melancholy, with little of Perry's humor. If you came for Perry's wit and the speed of the storytelling, begin with Bill, the Galactic Hero or The Ghost Brigades, or one of the more action-forward series further down. Each entry below says how it feels compared with Scalzi's novel, not only what it is about.
If You Loved the Bargain
1. The Forever War by Joe Haldeman (1974)
Haldeman was a draftee combat engineer in Vietnam, and his novel is often read as a counterpoint to Heinlein’s Starship Troopers, built on the alienation of his own war experience. It won the Nebula Award in 1975, then the Hugo and Locus Awards in 1976. The soldier, William Mandella, fights an interstellar war while relativity quietly steals his life. At speeds near light, time passes more slowly for the traveler than for the people left behind, so a few years of service can mean decades back home. The physics is the cruelty: the home you remember is gone before you return. Compared with Old Man’s War: colder, more melancholy, and far less funny. Best for: readers who want the bruised version of the premise.
2. Starship Troopers by Robert A. Heinlein (1959)
The book Scalzi was in conversation with, and the work most often treated as the founding text of the subgenre. It won the Hugo Award in 1960 and follows a recruit through training and war in a society the novel largely admires. Read it for the powered armor, the boot camp, and the arguments about service that later writers answered. Compared with Old Man's War: more political exposition and philosophy, and a very different politics from the other books here. Best for: readers who want to see where the argument started.
3. Bill, the Galactic Hero by Harry Harrison (1965)
The funniest book on this list. Bill is a farm boy who wants nothing more than to work the land, and he is tricked into joining the Space Troopers, then dragged through a brutal boot camp and a series of cynical misadventures. It is often read as a satire of Starship Troopers and of military science fiction clichés more broadly. Compared with Old Man's War: the comedy is broader, more absurd, and more biting than Scalzi's wit, but it shares the premise of a recruit who learns that the deal was not what he was sold. Best for: readers who loved the humor most.
If You Loved the Body
4. Armor by John Steakley (1984)
On the hostile planet Banshee, a scout named Felix survives mission after mission against an insectoid horde, protected by nuclear-powered armor and a cold fighting instinct he calls the Engine. The title also points at the emotional armor soldiers build to stay alive. A second storyline follows a space pirate who finds Felix's armor years later. Reviewers often place the novel alongside Starship Troopers and The Forever War. Compared with Old Man's War: much darker and more intense, with a psychological focus on trauma and almost none of Perry's lightness. Best for: readers who loved what the new body does to a mind.
5. The Ghost Brigades by John Scalzi (2006)
The obvious next step. It is a direct sequel to Old Man's War, but it moves away from John Perry and onto the special forces units, whose recruits are built for war from the start. That change of perspective turns the book's questions toward identity: what does it mean to be made for a purpose you did not choose? Compared with Old Man's War: you lose Perry's voice, but you keep Scalzi's pace and storytelling. Best for: readers who want more of the same universe without repeating the same character.
If You Loved the Training and the Lie
6. Ender’s Game by Orson Scott Card (1985). A child is recruited into a battle school where games are designed to break and sharpen him at once. It won the Nebula Award in 1985 and the Hugo Award in 1986. It sits on the border of the subgenre: the site’s guide to military space opera argues it leans toward that shelf, because what survives without the war is a government’s moral debt. For the revolution-and-academy version of the same pressure chamber, see books like Red Rising. Compared with Old Man’s War: a child’s point of view, with none of Perry’s adult perspective or wry humor, and a colder reading of institutional manipulation. Best for: readers who loved the lie underneath the war.
7. War Girls by Tochi Onyebuchi (2019)
Nigeria and Biafra are at war again in 2172, and two sisters raised in a camp for child soldiers end up on opposite sides of it. Published as young adult science fiction, it uses mechs and bionic limbs to make the cost of child soldiering visible. It is one of the few books here written from the point of view of the people a war is fought over. More titles in this vein are in the guide to Black military science fiction. Compared with Old Man’s War: emotionally heavier and more urgent, with little comic relief. Best for: readers who want the question “who is this war for?” asked bluntly.
If You Loved the War Itself
8. Hammer's Slammers by David Drake (1979)
A collection of stories about a future mercenary tank regiment led by Colonel Alois Hammer. Drake based the Slammers on his own service with the 11th Armored Cavalry Regiment in Vietnam and Cambodia, and chose to move that experience into a far-future setting instead of writing about Vietnam directly. Compared with Old Man's War: hard, episodic, and unsentimental, focused on the line soldier and not on a single wry narrator. Best for: readers who want combat written by someone who has seen it.
9. The Lost Fleet: Dauntless by Jack Campbell (2006)
Captain John "Black Jack" Geary wakes after a century in cryogenic sleep to find his side losing a long war and himself turned into a legend. It starts a six-book main series about fleet command under pressure. Compared with Old Man's War: the view shifts from one infantry soldier's experience to fleet-level strategy, and the book leans closer to space opera than most of this list, though the daily problem is still command. Best for: readers who liked Perry's rise through the ranks and want to command a fleet.
10. Legionnaire by Jason Anspach and Nick Cole (2017)
Book one of the Galaxy's Edge series. An elite fighting force is ambushed and stranded behind enemy lines on an alien world, and a sergeant has to lead the survivors out against insurgents. Compared with Old Man's War: faster, pulpier, and more action-forward, with a squad-level focus and a long series ahead. Best for: readers who want speed and a series to commit to.
Military Sci-Fi vs. Military Space Opera
Some books people often recommend after Old Man’s War are missing from this list on purpose. Dune, Red Rising, and Ninefox Gambit all feature war, but they widen the lens to empires, caste systems, and institutions, and a political story survives without the fighting. That is the military space opera shelf, and the site’s list of the best military space opera books is the place to browse it. For the broader genre boundary, space opera vs. hard sci-fi explains how the labels overlap.
Where a book's weight falls is a matter of degree, and plenty of titles, including Ender's Game and The Lost Fleet, sit on the line. Two books featuring interstellar battles can feel completely different depending on whether the story stays with the soldier or pulls back to the government that sent him. If Old Man's War hooked you through Perry, you probably want the first kind.
What I Look for in a War Story
I read and write science fiction, and the war itself is rarely what stays with me. The battles and the hardware are a big part of why I pick these books up, and I enjoy them. But the story lives in the characters. Why are they fighting? What do they stand to lose besides their lives? Is it hatred of the enemy, love of country, a sense of duty, or something waiting back home? Real wars have always held all of those motives at once. The people who went to fight the Nazis in World War II did not all go for the same reason, and the best fiction lets different characters carry different ones.
What interests me most is the stretch just before a battle and just after it. What does the character do with the fear, and what does it cost them? How do violence and loss change them, and what do they carry into the next fight? John Geary in The Lost Fleet is a good example. As I read Dauntless, much of it happens inside his head: the pain he feels over every ship he loses, the way he blames himself, and his reluctance to lead the fleet at the start, which tells you more about him as a leader than any tactical decision. That inner pressure is what turns fleet maneuvers into a story, and it is the same quality that makes Perry's grief matter in Old Man's War.
What These Stories Have in Common
Read the earliest of these books in order and a conversation starts to show. Heinlein's 1959 novel treats military service as the price of citizenship. Harrison, in 1965, turned that premise into satire. Haldeman, drafted into Vietnam, wrote a book often read as its counterpoint. Drake, back from the same war, moved his experience into a tank regiment on a distant world. Steakley turned the armored suit into a psychological question. Scalzi, writing in 2005, joined the argument with a 75-year-old narrator, a sense of humor, and a sharp eye for the fine print.
Military science fiction keeps circling one question: what is a soldier owed? The best books in it do not settle the answer. They make you feel the gap between what was promised and what was paid, in whatever tone suits the writer, from satire to grief.
Reading List: Where to Start
- Want more of Scalzi himself: The Ghost Brigades, then The Last Colony.
- Want the funniest option: Bill, the Galactic Hero.
- Want the argument that shaped the book: Starship Troopers, then The Forever War.
- Want the body-and-mind angle, and can handle darker: Armor.
- Want combat from a veteran’s pen: Hammer’s Slammers.
- Want speed and a long series to commit to: Legionnaire, or The Lost Fleet for fleet command.
- Want to branch into war used to test empires: the best space opera series is the next stop.
Frequently Asked Questions
What are the best books like Old Man's War?
The closest matches by theme are The Forever War by Joe Haldeman, Starship Troopers by Robert A. Heinlein, and Armor by John Steakley. For more of Scalzi's own voice, read The Ghost Brigades. For humor, try Bill, the Galactic Hero by Harry Harrison. For combat and series length, add Hammer's Slammers by David Drake and The Lost Fleet: Dauntless by Jack Campbell.
Is Old Man's War military sci-fi or space opera?
It is usually classified as military science fiction. The story stays close to a soldier’s experience inside a military structure, and the political world behind the war stays largely in the background. Space opera tends to widen the lens to governments and civilizations. The categories overlap, but Old Man’s War sits on the military science fiction side. See the military space opera guide for more on the boundary.
Is Old Man's War similar to Starship Troopers?
Yes, deliberately. Scalzi has said Heinlein's novel inspired his debut, and both follow a recruit through training and war against alien enemies. The differences are the narrator, a grieving 75-year-old placed in a new body, and the tone, which is funnier and more skeptical than Heinlein's.
Is The Forever War as funny as Old Man's War?
No. The Forever War shares Old Man's War's interest in what military service takes from a person, but it is colder and more melancholy, with little humor. For funnier readalikes, try Bill, the Galactic Hero, a satire of military science fiction, or stay with Scalzi's own sequels, beginning with The Ghost Brigades.
In what order should I read the Old Man's War series?
Start with Old Man's War (2005), then The Ghost Brigades (2006) and The Last Colony (2007). Zoe's Tale (2008) retells events from The Last Colony from a different point of view, so it works well after it. The Human Division (2013) and The End of All Things (2015) continue the story.
Sig Watkins is the author of The Last Marshal, a cinematic science fiction novel published in 2026 and set in a future of stealth ships, deep space, and political conspiracy. The prequel short story, Cell Seven, is available free at SigWatkins.com.