[[quoteright:150:http://static.tvtropes.org/pmwiki/pub/images/wehikul_1287.png]]
[[caption-width-right:150:[-The series logo. [[VideoGame/{{Portal}} We know what you're thinking.]]-] ]]

If you're looking for the classic novel by H. G. Wells, see ''Literature/TheTimeMachine''.

'''''Time Machine''''' is a series of educational ChooseYourOwnAdventure books, published by Bantam Books in 1984-1989. Unlike many other works of this genre, the books only have one ending, reached usually by trial-and-error.

The premise is that the player is tasked by some unknown authority to travel to the past in order to unravel a historical mystery. Following a strict set of time-travel rules, the protagonist finds himself skipping back and forth through several centuries of history, braving dangers and somehow always coming across famous historical figures.
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!!The series as a whole displays examples of:

* CantTakeAnythingWithYou: Leaving items from a future epoch behind is one of the things forbidden by the "time travel rules".
* ChangedMyJumper: The protagonist is always careful to take clothes appropriate for his destination; when he time-travels into different eras entirely, some people may casually comment on his weird clothes.
* CoversAlwaysLie: At least in the Polish edition, the back covers sometimes feature a situation from the book and hint that you will have two choices in that situation (and that if you choose wrong, you'll end up stuck in a time loop). Most of the time, it turns out that when this part comes in the book, you don't actually have the choices presented by the cover.
** The Polish cover for ''Mystery of the Atlantis'' deserves a special mention: it claims that the Olympic games featured in the book are the ''first'' Olympic games (something that isn't in the book)... [[YouFailHistoryForever and this claim on the cover is accompanied by a huge headline stating "it's the year 400 BC", while Olympic games actually started at least two centuries earlier!]]
* GroundhogDayLoop: Supposedly, if you break the time travel rules, you risk being trapped in one of these. In practice, an easier way to end up in one is to [[UnwinnableByDesign take the wrong inventory item at the beginning]].
** Since bad choices make you re-read pages you've read already, the protagonist technically falls into a few short loops (with two or three iterations, tops) on his every adventure. (Since some of them involve arduous weeks- or even months-long trips, it's probably not pleasant...)
* HintSystem: The last page contains hints that help you in choosing the right path on some pages.
* InSpiteOfANail: On one hand, the rules forbid you from changing history; on the other hand, the protagonist tends to save random people's lives without a thought, even if they would die without his being there.
* InThePastEveryoneWillBeFamous: Your time machine apparently has a mind of its own and a thing for depositing you just at the right time and place.
* InventoryManagementPuzzle: So, you can take a tiny compass... a tiny lockpick... OR a huge unwieldy scary mask, but only ONE of these.
** Strangely, this is often broken by the fact that if you choose the WRONG one, you are stuck when it comes to that point in the book.
* KidHero: The protagonist. The exact age is unclear, but seems to be somewhere around 13. Which doesn't stop him from people occassionally [[ImprobableAge treating him as someone older for sake of the plot]]; for instance, he can end up becoming a full-fledged astronaut.
* PlotHole: Sometimes, if you take a specific path, the protagonist will end up knowing things he shouldn't.
* POVCam: All the illustrations are from the protagonist's point of view.
* PresentTenseNarrative: As usual in a gamebook.
* SecondPersonNarration: Also usual for a gamebook.
* TimeMachine: Gee, ya think?
* TimeTravel: Why, yes, it tends to come up.
* TimeTravelersAreSpies: Commonly happens to you, such as being accused of being a Mexican spy in the American-Mexican war when you fail to correctly name the American president and general.
* UnwinnableByDesign: Some books offer you a few items in the beginning, and you have to choose one to take. Usually, choosing the wrong one will get you [[GroundhogDayLoop stuck]] halfway through.
* WhatYearIsThis: Not only that, but the protagonist also tends to be surprisingly oblivious about pretty much everything about the era where he's going. Rarely does this get him anything worse than a weird look.
* TheXOfY: A lot of the titles.
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!!The individual books:

!Secret of the Knights (1984)
!Search for Dinosaurs (1984)
The protagonist must take a picture of an Archaeopterix, the first bird. Most of the book consists of figuring out ''where'' and ''when'' the Archaeopterix lived, by hopping back and forwards through the Mesozoic and piecing together information.
* AlasPoorVillain: A T-rex slowly starving in the aftermath of the meteorite fall is a rather pitiful sight, even if it tried to eat you previously.
* ApocalypseHow: You get to witness the Cretaceous mass extinction, which is a class 4.
* BigCreepyCrawlies: You meet some impressively large dragonflies in the Triassic period.
* EverythingsBetterWithDinosaurs
* NeverSmileAtACrocodile: Especially 30-feet Cretaceous crocodiles.
!Sword of the Samurai (1984)
!Sail with Pirates (1984)
The protagonist accompanies Captain Phips in the seventeenth century in order to find the wreck of ''Concepcion'', a Spanish ship carrying colossal amounts of silver.
* FortuneTeller: Old, blind, but oddly knowledgeable black woman who gives you cryptic hints (and is one of the few persons to know about your time travel.)
* {{Futureshadowing}}: The very beginning of the book has you meet a man who [[HaveWeMetYet mentions meeting you before]], and is talking about things you'll do much later (from your perspective), while time-travelling into the past. [[TemporalParadox Strangely, it's possible to finish the adventure without ever actually doing the things the man mentions you doing...]]
* GoMadFromTheIsolation: The pilot from ''Concepcion'' after [[{{Robinsonade}} being alone for a]] ''long'' time.
* {{Jerkass}}: Jim Teal, a young sailor whose emnity you accidentally earn in the past... late in the book (damn time travel), and who subsequently bullies you the entire time you're his crewmate.
* TheLongitudeProblem: The reader gets stranded on a small island in the Caribbean with some sailors. There's an argument when the sailors try to determine their latitude and the reader suggests figuring out their longitude. This is immediately shot down as impossible. Which is decidedly odd, because figuring a longitude of a ''fixed place'', instead of moving ship, is relatively easy, if a somewhat long process. Of course, these are common sailors who may not have the math or astronomical skills necessary to carry out that process.
* {{Pirates}}: Gritty, realistic type. They aren't dashing and romantic.
!Civil War Secret Agent (1984)
!The Rings of Saturn (1985)
An OddballInTheSeries, as it sends the protagonist to TheFuture. This frees the writer from the shackles of historical accuracy, making the book essentially a {{Troperiffic}} showcase of pretty much every single ScienceFiction trope in the book. The protagonist's mission is finding out the source of mysterious signals coming from Saturn.
* AirVentPassageway: Used to escape from the nasty SpacePirates.
* {{Cyborg}}s: Quite a lot of them, and some consider themselves superior to mundane humans.
* DrillSergeantNasty: You run into one of these when you train to be an astronaut. If you screw up, you end up reassigned to train elsewhere under an [[UpliftedAnimal intelligent dolphin]]. Who's even ''nastier''.
* FantasticRacism: Humans fear cyborgs. It's meant to be shown as intolerance, but, interestingly, [[BrokenAesop pretty much all cyborgs you meet on your way are in fact evil]].
* MadScientist: Who transports you into AnotherDimension against your will.
* PsychicPowers: Several {{mutant}}s with a multitude of powers, living in a wildlife preserve. Their powers range from {{telepathy}} through future sight to {{teleportation}}.
* RobotDog: Protecting the mansion of an important senator. It can be switched from ferocious guard dog mode to a lovable, face-licking pooch mode.
* SapientCetaceans: Telepathic dolphin officers, to boot.
* SpacePirates: Their crew made up of cyborgs with a secret base on the Moon.
* {{Terraforming}}
* TrailersAlwaysSpoil: The cover depicts [[spoiler:the alien who's only revealed at the end]].
* UndeadTaxExemption: Very noticeable in this setting--your address is explicitly said to be years out of date, and you're probably long dead in that era anyway, yet you're able to be enrolled into an elite academy with no problems.
* UnitedNationsIsASuperpower: And an OneWorldOrder, though benevolent.
* {{Veganopia}}: No meat to be seen around, just vegan food.
!Ice Age Explorer (1985)
!The Mystery of Atlantis (1985)
Travelling through AncientGreece, the protagonist is trying to find out [[CaptainObvious the mystery of]]... [[{{Atlantis}} take a guess.]]
* {{Atlantis}}: [[spoiler:But not really. It's just Crete.]]
* ChangedMyJumper: {{Averted}} here; you can time-travel all over the world and all over history, and nobody ever notices you're a kid in an ancient Greek chiton.
* FutureImperfect: Though not with the future; it is stated that [[spoiler:the tale of Atlantis is an exaggeration of a tale about a destructive volcano explosion near Crete, which caused the downfall of Cretan civilization.]]
* GalleySlave: You can temporarily become this.
* OutOfCharacterAlert: If you try and tell a suspicious city guard that you are a Scyth, he will promptly quiz you on a piece of Scythian culture (since he is a Scyth himself.) You fail, at which point he decides you're a runaway slave.
!Wild West Rider (1985)
!American Revolutionary (1985)
!Mission to World War II (1986)
!Search for the Nile (1986)
The protagonist heads to the late nineteenth century to accompany Henry Morton Stanley in order to find out what is the source of Nile.
* ArcWords: "Buala Matari". What's it mean, and why is Stanley called that on his tomb?
* GodGuise: Entirely by accident you end up scaring an African tribe, disguised as a panther-like supernatural being. The shaman isn't fooled though.
* GreatWhiteHunter: Sir Mortimer P. Quimby III. Subverted - this particular hunter is content merely to track down the animal and aim his rifle without actually shooting, solely for the satisfaction of outwitting the beast.
* InsistentTerminology: Do not call Henry Stanley "captain". Or else he will... well... chastise you mildly.
!Secret of the Royal Treasure (1986)
!Blade of the Guillotine (1986)
The protagonist finds himself in the times of FrenchRevolution, seeking a [[http://en.wikipedia.org/wiki/Affair_of_the_Diamond_Necklace priceless diamond necklace]]. The objective soon shifts from merely finding the treasure to using it to buy the life of an innocent French girl.
* BlindAlley: Used to escape an angry royalist blacksmith.
* KangarooCourt: Invoked; if you're not carrying [[InventoryManagementPuzzle the correct item]] at one point, your character is arrested as an enemy of the French Revolution. You demand a fair trial and your captors respond that [[BlatantLies you will get a fair one]]...and then you'll most likely be guillotined.
* MacGuffin: The necklace, natch.
* RiddleMeThis: Subverted. When given a cryptic answer about the necklace's location, you have to interpret the "riddle" literally. If you try to be smart and go for the metaphorical meaning, you'll just end up in trouble.
!Flame of the Inquisition (1986)
* ChangedMyJumper: Deconstructed. One possible decision has you jump to New England around the time of the Salem Witch Trials. Since you're dressed in clothing from around the time of the Spanish Inquisition, you not only stick out like a sore thumb; you also get accused of being a witch.
* TrespassingHero: If you made a wrong choice, you were arrested by knights during your travels for unknowingly trespassing on their duke's land.
!Quest for the Cities of Gold (1987)
The protagonist heads to America in the sixteenth century in order to investigate the rumors of the supposed "cities of gold" searched for by the conquistadors.
* GoLookAtTheDistraction: Used to escape an Aztec guard to avoid fate of a HumanSacrifice, by persuading him to look outside at a supposed earthquake so that you can time-travel out of your prison. [[UnwinnableByDesign Not that it will help you if you've ended up in that paragraph.]]
* HumanSacrifice: Almost done to you by Aztec priests (who else in that era and location?)
* NeverSmileAtACrocodile: The protagonist ends up in the Florida swamps at one point, and while exploring along with an Indian boy they end up attacked by alligators. The boy escapes, while the protagonist time-travels his way out of there.
!Scotland Yard Detective (1987)
The mission is to help Scotland Yard solve a major case with political implications. An Indian prince vanishes, straining tense relations between the British Empire and India.
* KidDetective: The protagonist becomes one of these as it is the mission to help Scotland Yard solve the aformentioned case. Later on, you meet another Scotland Yard operative, revealed to be a female and not much older than the protagonist!
* ShownTheirWork: The text makes mention of new crime solving tools coming into use around that time such as photography and fingerprinting.
!Sword of Caesar (1987)
!Death Mask of Pancho Villa (1987)
!Bound for Australia (1987)
!Caravan to China (1987)
!Last of the Dinosaurs (1988)
The protagonist must find the very last of the dinosaurs prior to their extinction and as proof, bring back a dinosaur tooth.
* BittersweetEnding: [[spoiler: The solution has you fulfilling the mission by finding a dinosaur tooth from a nearby carcass. However, you see a freshly hatched baby dinosaur nearby poking around its dead mother; the text tells you that [[TearJerker it will not survive long]].]]
!Quest for King Arthur (1988)
The protagonist travels through ancient Britain, attempting to find the original inspiration for the KingArthur tales.
* HumanSacrifice: Almost done to you by some druids at one point.
* MadeASlave: You become a Saxon's farmhand.
!World War I Flying Ace (1988)
!Special Edition: World War II Code Breaker (1989)
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