The Four Worlds: Similar series
Old Man's War
by John Scalzi
4.02 · 552 ratings
sci-fi · space-opera · fiction · space · audiobook · book · military · violent-conflict · adult · aliens · war · colonization · space-travel · action-adventure · humor · soldiers · exploration · genetic-engineering · galactic-empire · politics
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Renegade Star
by J.N. Chaney
4.32 · 237 ratings
book · first-contact · space · steampunk · industrial-era · exploration · fiction · space-travel · sci-fi · historical · genetic-engineering · space-opera · violent-conflict · adult · military · audiobook · cyberpunk · galactic-empire · colonization · action-adventure
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Merkiaari Wars
by Mark E. Cooper
4.05 · 72 ratings
galactic-empire · space-travel · space-opera · soldiers · space-fleet · adult · genetic-engineering · space · violent-conflict · first-contact · audiobook · military · war · sci-fi · book · invasion · aliens · exploration · fiction · action-adventure
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The Terran Fleet Command Saga
by Tori L. Harris
4.29 · 69 ratings
aliens · exploration · colonization · fiction · book · technothriller · invasion · post-apocalyptic · genetic-engineering · space · space-fleet · adult · audiobook · military · violent-conflict · first-contact · space-travel · space-opera · galactic-empire · soldiers
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NeoG
by K.B. Wagers
4.01 · 33 ratings
action-adventure · galactic-empire · audiobook · space · genetic-engineering · book · colonization · sci-fi · space-opera · military · adult · space-fleet · lgbtq · fiction · mystery · found-family · post-apocalyptic · female-author · violent-conflict · war
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Invaders
by Vaughn Heppner
4.13 · 30 ratings
colonization · galactic-empire · action-adventure · aliens · exploration · fiction · invasion · book · drama · military · audiobook · space · genetic-engineering · adult · space-fleet · soldiers · violent-conflict · sci-fi · space-opera · space-travel
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Aurora Rhapsody
by G.S. Jennsen
4.27 · 113 ratings
space-opera · space-travel · sci-fi · military · fiction · action-adventure · cyberpunk · colonization · space-fleet · violent-conflict · first-contact · exploration · galactic-empire · space · adult · aliens · book · soldiers · ai · invasion
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Baldwin's Legacy
by Nathan Hystad
4.26 · 23 ratings
aliens · fiction · sci-fi · space-opera · military · space · adult · invasion · violent-conflict · book · soldiers · space-travel · galactic-empire · first-contact · genetic-engineering · space-fleet · colonization · action-adventure · exploration · audiobook
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Starcaster
by J.N. Chaney
4.39 · 38 ratings
space-travel · space-opera · galactic-empire · genetic-engineering · violent-conflict · historical · adult · military · first-contact · book · steampunk · industrial-era · action-adventure · exploration · fiction · audiobook · fantasy · sci-fi · space · invasion
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Justice of the Covenant
by M.R. Forbes
4.50 · 22 ratings
space-opera · soldiers · sci-fi · adult · space-fleet · space · genetic-engineering · first-contact · violent-conflict · military · audiobook · shapeshifters · book · futuristic · invasion · aliens · fiction · galactic-empire · dystopia · female-mc
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Broken Worlds
by Jasper T. Scott
4.05 · 22 ratings
galactic-empire · cyberpunk · dystopia · genetic-engineering · space · invasion · soldiers · historical · adult · space-fleet · violent-conflict · sci-fi · first-contact · military · industrial-era · steampunk · aliens · fiction · book · supernatural
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Star Crusades Uprising
by Michael G. Thomas
3.73 · 58 ratings
galactic-empire · action-adventure · aliens · fiction · invasion · book · military · space · adult · space-fleet · soldiers · violent-conflict · sci-fi · space-opera · genetic-engineering · war · box-set · first-contact
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Aurora Renegades
by G.S. Jennsen
4.46 · 28 ratings
action-adventure · aliens · exploration · fiction · military · first-contact · violent-conflict · space-fleet · adult · soldiers · sci-fi · space-travel · space-opera · colonization · invasion · book · audiobook · space · cyberpunk · utopia
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Legacy War
by John Walker
4.24 · 34 ratings
aliens · exploration · fiction · colonization · book · invasion · genetic-engineering · space · space-fleet · adult · violent-conflict · military · first-contact · space-travel · space-opera · galactic-empire · sci-fi · audiobook
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The Movement Trilogy
by Jason Gurley
3.67 · 25 ratings
adult · book · fiction · sci-fi · post-apocalyptic · aliens · dystopia · invasion · futuristic · cyberpunk · apocalyptic · space-fleet · colonization · supernatural · violent-conflict · exploration · soldiers · space-opera · space-travel · galactic-empire
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Project: Adapt
by Jade Waltz
4.14 · 29 ratings
adult · romance · polyamory · space-opera · sci-fi · fiction · aliens · royalty · reverse-harem · book · fated-mates · genetic-engineering · paranormal · action-adventure · poc-mc · female-mc · colonization · first-contact · assassins · epic
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Angel 6.0
by Travis Luedke
3.84 · 25 ratings
space-opera · romance · book · steamy · space · paranormal · aliens · fiction · futuristic · adult · dark · sci-fi · cyberpunk · genetic-engineering · galactic-empire · kidnapping · captivity · audiobook · alpha-mc · action-adventure
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Lone Wolf Squadron
by Jamie Davis
4.70 · 23 ratings
space-travel · galactic-empire · soldiers · sci-fi · space · genetic-engineering · violent-conflict · space-fleet · military · first-contact · book · invasion · humor · aliens · exploration · fiction · adult · space-opera · supernatural · young-adult
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Spectras Arise Trilogy
by Tammy Salyer
3.94 · 18 ratings
action-adventure · fiction · book · military · violent-conflict · space · genetic-engineering · adult · space-fleet · soldiers · sci-fi · space-opera · galactic-empire · war · female-mc · mystery · female-author
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Central Galactic Concordance
by Carol Van Natta
4.11 · 37 ratings
genetic-engineering · fiction · space-opera · adult · romance · book · space · action-adventure · sci-fi · military · paranormal · suspense · galactic-empire · aliens · audiobook · futuristic · psychics · soldiers · space-travel · violent-conflict
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Here Comes Earth
by William Lee Gordon
3.73 · 11 ratings
adult · invasion · violent-conflict · book · aliens · fiction · sci-fi · first-contact · hard-sci-fi · exploration · space-travel · space-opera · galactic-empire · genetic-engineering · space · time-travel · action-adventure · audiobook · military · space-fleet
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The Chronicles of Nuala
by Katharine Eliska Kimbriel
4.00 · 8 ratings
colonization · galactic-empire · space-opera · sci-fi · adult · genetic-engineering · space · book · romance · fiction · action-adventure · political-intrigue · survival · hard-sci-fi · dystopia · female-author · audiobook · fish-out-of-water · high-fantasy · mystery
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Riven Worlds
by G.S. Jennsen
4.70 · 10 ratings
sci-fi · soldiers · space-opera · space-travel · first-contact · military · adult · space-fleet · violent-conflict · aliens · exploration · fiction · action-adventure · galactic-empire · cyberpunk · space · genetic-engineering · invasion · book · technothriller
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Mindspace
by A.K. DuBoff
4.44 · 9 ratings
galactic-empire · supernatural · space-opera · soldiers · sci-fi · adult · genetic-engineering · space · military · book · aliens · fiction · action-adventure · violent-conflict · colonization · first-contact
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