Keith Laumer (1925 - 1993) was an American science fiction writer. He is particularly known for the UsefulNotes/NebulaAward-nominated novel ''A Plague of Demons'', and for two series:

* Literature/{{Bolo}}. The bolos are automated battle-tanks, originally developed to reduce the number of human crew required; later models are able to perform programmed tasks without any crew at all, and still later models are self-aware artificial intelligences in armor-plated bodies equipped with enough firepower to conquer an entire planet single-handed. The series is a set of mostly self-contained stories sampling events across the history of bolo development; in the later stages, the sometimes-tense relationship between the bolos and the humans they serve is inevitably a feature. This has become a SharedUniverse, with authors like Creator/DavidWeber and Creator/JohnRingo being the most recent contributors.
* Literature/{{Retief}}. Satirical series of stories about the travails of Jame Retief, a junior member of Earth's interstellar diplomatic corps. Inspired by Laumer's career in the United States Foreign Service.

His humorous AlienInvasion thriller, ''The Monitors'', was made into a fairly faithful low-budget movie in 1969, and his humorous HardboiledDetective story ''Deadfall'' was made into the 1976 movie ''Peeper'' starring Creator/MichaelCaine and Creator/NatalieWood.
!!Works by Keith Laumer with their own trope pages include:
* ''Literature/{{Bolo}}'' series
* ''Literature/{{Retief}}'' series
* ''[[Literature/DangerousVisions "Test to Destruction"]]''
!!Other works by Keith Laumer provide examples of:

* AlternateHistory: The ''Worlds of the Imperium'' series includes one where WWI and the Russian Revolution never happened, one where Neanderthals ruled, one where Napoleon beat the British, and one where rats became the dominant sentient species.
* AlternateTimeline: ''Worlds of the Imperium'' more or less deconstructs this. Decision points spawn alternate universes, but the vast majority of them are barren and devoid of life because the direction of technological experimentation which can eventually lead to an interdimensional travel machine turns out to be ''millions'' of time more likely to to lead accidentally to an apocalyptic weapon. Hence, only a bare few timelines with advanced technology actually survive.
* BenevolentAlienInvasion: ''The Monitors'' has benevolent aliens ruling the Earth, "opposed" by various misfit rebels.
* BrainInAJar: In ''A Plague of Demons'', human brains are installed in alien war machines.
* CuckooNest: ''Knight of Delusions'' (also published, confusingly, as ''Night of Delusions'') puts its hero through an insane number of alternate realities. Every time it becomes entirely unbelievable, he gets put into yet another one and is back at square one, trying to figure out if he's completely out or if he's stuck in yet another false reality.
* DoorstopBaby: One story featured a huge insect- or crustacean-looking thing that took the army with lots of artillery to kill it -- and then they decoded the message which read, "Please take good care of my little girl."
** ''[[ Doorstep]]''.
* EasilyThwartedAlienInvasion: A short story in which aliens invade a dying civilization -- only to discover that the locals were in fact immortals whose metabolisms shut down if they didn't get enough of a certain gas in their air. Guess what the invaders exhaled. And the locals who were still up and about were the ''weakest'' of their species; the invasion revived all of their brawny badasses.
* GenocideDilemma: In ''The Glory Game'', after the warlike alien Hukk are defeated, the Terran Hardliners want to wipe them out to keep them from threatening Earth again.
* InstantExpert: In ''Galactic Odyssey'', the protagonist is put to work sorting indistinguishable glorm-bulbs... which turns out to give him the ability to learn essentially anything with a single run-through.
* RepetitiveName: Chester W. Chester IV in ''The Great Time Machine Hoax''.
* SocietyMarchesOn: "[[ Cocoon]]" has everyone living in virtual reality tanks a couple hundred years in the future. The husband "goes" to a virtual office and does virtual paperwork, while the wife sits at "home", does virtual housework and watches virtual soap operas all day. When the husband comes "home", he complains because the wife hasn't gotten around to punching the selector buttons for the evening nutripaste meal yet.
* VichyEarth: ''The Monitors''