He received lifetime achievement awards from the World Science Fiction Society (which runs the Hugo Award), the Science Fiction and Fantasy Writers of America (which run the Nebula Award), and the organisers of the Sidewise Award for Alternate History.
Works by L. Sprague de Camp with their own trope pages include:
- Conan the Barbarian series
- Harold Shea series
- Lest Darkness Fall
- The Pusadian Series
- Viagens Interplanetarias series
Other works by L. Sprague de Camp provide examples of:
- Agony of the Feet: The educational book Energy and Power includes a discussion of the difference between the potential energy of a one-pound weight sitting on a three-foot-high table and the kinetic energy if the weight falls off the table, and adds, "You will understand this if the weight falls on your toe."
- All Cavemen Were Neanderthals: The caveman protagonist of "The Gnarly Man" is a Neanderthal.
- Alternate Self: The premise of the short story "The Wheels of If" is that, as part of a ploy to discredit a political rival, someone in an Alternate Universe comes up with a way to cycle the consciousnesses/souls of seven people in seven universes who happen to be similar enough to count as Alternate Selves. The rival is one of these, ending up with the mind of a man from our timeline.
- Animal Athlete Loophole: In the short story "Nothing in the Rules", one team at a girls' swimming competition contains a mermaid, who wins every race she enters. (To avoid disqualification for not using the proper swimming form, the mermaid only competes in the freestyle events.) In response to the opposition's outrage, the team coach points out that the rules only specify that all entrants must be female; nothing is said about species. The officials are reluctantly forced to admit that he's right. Whereupon the opposing coach visits the city zoo and borrows a female seal, who (properly incentivized with a bucket of fish) outswims the mermaid.
- Butterfly of Doom: In "Aristotle and the Gun" an arrogant time traveler tries to change history, and achieves the exact opposite of what he intends.
- Contemporary Caveman: "The Gnarly Man" is about a Neanderthal named Shining Hawk whose aging process was frozen when he was struck by lightning early in his life. He has survived by his wits on the periphery of human society since the extinction of his own kind, using a succession of false identities and getting by as a blacksmith or in menial professions like his present one; appearing as as an 'ape man' in a travelling freak show. He has been a witness to much of history from the margins, making little personal impact on it. He's also frustrating as hell to the scientists trying to get information from him, both cause he's deliberately tried to be low-key and stay away from important/influential people (he mentions at one point the only King he ever even personally saw was Charlemagne, from a distance when he was addressing a crowd) and because every conversation about history goes like "Yeah, that was in the 13th century. No, wait, maybe it was the 11th. I remember all the bystanders had beards, so it wasn't the 12th..."
- Conveniently-Placed Sharp Thing: Lampshaded in The Goblin Tower, part of the Reluctant King series. Fugitive king Jorian, the wizard Karadur, and the woman Vanora have been tied up in Jorian's bedroom by a couple of other wizards. Jorian's sword is hanging by its baldrick on his hatrack, and though Jorian has his ankles and wrists bound, he manages to worm himself to his feet, knock the hatrack over, and (with the help of Vanora's feet) cut through his bonds. Prompting this exchange after he releases the others:Jorian: These knaves were tyros after all, or they'd never have left aught sharp where we could come upon it.
Karadur: Remember, my son, that they are accustomed to coping with foes, not by such crude devices as swords and cords, but by spirits, spells, and the transcendental wisdom of magic.
Jorian: So much the worse for them.
- Dream Land: Solomon's Stone takes place in a world populated by figures from daydreams.
- Dumb Dinos: In "A Gun for Dinosaur", the dinosaurs' stupidity makes hunting them difficult due to the small size of their brains, preventing easy headshots. Because they have no memory, though, it's easy to escape their attention by hiding - they'll simply forget about you.
- Eternal English: Deconstructed in "Language for Time Travelers".
- Finders Rulers: In the Reluctant King series, the kingdom of Xylar chooses its next king by throwing the head of the previous king into a crowd — the catcher gets the throne. The downside is that in five years, the process is repeated... which is why Jorian, who had no idea about all this, is very much the titular Reluctant King, and spends the trilogy running away from Xylarians who want to drag him back so they can perform the ceremony.
- Inn Between the Worlds: The setting of Tales From Gavagan's Bar.
- Intelligence Equals Isolation: In the story "Judgment Day", a scientific genius has discovered a principle that will make weapons on the scale of A-bombs (which hadn't been fully invented yet when the story was written) possible. Most of the story is a flashback to his unhappy life of being unpopular and bullied and lonely, with him trying to argue himself into not publishing despite this out of what remains of his conscience. The straw that breaks the camel's back is returning to his home to find local teens have vandalized his home in an over-the-top prank. He decides to publish his discovery, expecting it to lead to humanity destroying itself.That decided me. There is one way I can be happy during my remaining years, and that is by the knowledge that all these bastards will get theirs someday. I hate them. I hate them. I hate everybody. I want to kill mankind. I'd kill them by slow torture if I could. If I can't, blowing up the earth will do. I shall write my report.
- In the Past, Everyone Will Be Famous: Averted in the short story "The Gnarly Man". The title character is a 50,000 year-old Neanderthal who has managed to live a quiet, normal life over the millenia. The only famous person he ever encountered was Charlemagne, who he saw giving a speech in Paris.
- Invented Individual: In "The Wheels of If" Allister Park, a New York lawyer from our world, is transported into the body of his counterpart in an Alternate History world, a bishop named Ib Scoglund. He concocts a plan to get himself home and manipulates the political opposition by infiltrating them using an invented identity... under the name "Allister Park".
- Just Like Robin Hood: In The Fallible Fiend, the leader of a bandit gang announces that they rob from the rich and give to the poor and since they themselves are the poorest people they can find...
- Literal Ass-Kicking: The Dragon of the Ishtar Gate has a scene in which the hero, realizing that he nearly jeopardized their mission (and his mother's life) by drunken, arrogant stupidity, asks his closest friend to give him a good swift kick in the arse. When the friend obliges, the hero sighs and says he feels better now.
- Lost Colony: The Great Fetish is set on the distant planet Kforri (K-40), a world in the Mesozoic stage of evolution colonized by humans generations before, their technology lost as the result of a mutiny before landing (or crashing). The established religions of the roughly Bronze Age-technology, Medieval European-culture nations that have developed all embrace the doctrine of Evolution, which states that mankind arose from lesser native forms, while the emergent scientists have brought forth the heretical concept of Descensionism, maintaining that the lack of creatures similar to humanity indicates their ancestors came from elsewhere.
- Mermaid Problem: In a folk tale recounted in The Unbeheaded King, a mermaid and a human attempt to have sex. Since the mermaid is dolphin-based, finding the opening isn't a problem. However, almost drowning is.
- No Woman's Land: In The Honorable Barbarian, princess Nogiri of Salimor comments that Kerin of Novaria, with whom she has just entered into a Citizenship Marriage, is an incredible man and husband and wonders why all Salimorese women don't go to Novaria to find such wonderful men. The primary reason she says this is that Kerin doesn't beat her when she argues with him.
- The Nudifier: In the short story "The Exalted", the Mad Scientist prankster builds a device that nullifies friction and makes woven fabrics crumble to threads.
- Odd Job Gods: The short story "The Hardwood Pile" features Aceria, the one of the Tree Nymphs of Norway Maples. After all the Norway Maples in the area are cut down she becomes the Nymph of Piles of Wooden Boards that Used to Be Norway Maples. At the end of the story she becomes the Nymph of Nightclub Dance Floors Made of Wood From Norway Maples.
- Our Mermaids Are Different: Mermaids appear in several of de Camp's fantasy stories. In all of them (even ones in different continuities) the mermaids are part dolphin, rather than part fish. They are also streamlined for swimming, so the females breasts are generally smaller than those typically portrayed in mermaid art.
- Our Nudity Is Different: The Wheels of If has a scene on an alternate Earth where belly buttons are considered obscene...but nothing else is, resulting in Barely-There Swimwear of an unusual sort. The protagonist (who is from our Earth) doesn't realize this at first, he just notices that everyone seems to be walking around what he considers to be nude, so he takes his clothes off to fit in ... and is promptly arrested for "Shameful Outputting" of his navel (the person explaining exactly what he's being charged with can barely bring himself to say it).
- Prestige Peril: In the Reluctant King series, the kingdom of Xylar chooses its next king by throwing the head of the previous king into a crowd — the catcher gets the throne. The catch is that in five years, the process is repeated... which is why Jorian, who had no idea about all this, is very much the titular Reluctant King, and spends the trilogy running away from Xylarians who want to drag him back so they can perform the ceremony.
- Schizo Tech: Divide and Rule features trains pulled by elephants, knights with armor made of chrome steel and plexiglass, cavalry battles with radio correspondents, and castles that use canned food to outlast sieges, among many other things. This is because Earth has been conquered by aliens who give humans a fair degree of autonomy, but don't allow them certain technologies, such as explosives and motor vehicles.
- Sesquipedalian Smith: In Solomon's Stone, the hero finds himself in a world populated by the figures people daydream of being. Everyone has a Sesquipedalian Smith name, indicating first the daydream and then the mundane reality.
- Stock Dinosaurs: "A Gun for Dinosaur" (about time-traveling big game hunters) features Tyrannosaurus trionyches, a fictional cousin of "the famous rex."
- Temporal Paradox: In "A Gun for Dinosaur", one of the characters tries to change the past, and discovers the hard way that history protects itself against paradoxes.
- Uplifted Animal: "Johnny Black", a black bear given human-level intelligence by an experimental process that increased the efficiency of his synapses, was the protagonist of a series of short stories beginning with "The Command".