->''This is the Inner Sphere, thousands of planets colonized by humankind. Once it was united under the Star League, but for the last three hundred years it has been consumed by savage wars...''
-->-- '''Adam Steiner''', from the ''TabletopGame/BattleTech'' animated series.

A galaxy-wide conflict with GiantMecha spanning centuries is ripe for backstory, so [=FASA=] naturally encouraged filling out the TabletopGame/BattleTech universe. They licensed the creation of a series of ScienceFiction novels as the main medium for this. The continuity of these novels was incredibly well kept, mainly because the nature of the 'verse allowed for a very wide variety of characters and settings. Naturally, this led to an [[LoadsAndLoadsOfCharacters extremely large and diverse cast of characters]], which is probably the strongest point of the novels. Much of the setting's tone was (and continues to be) defined by Creator/MichaelStackpole, with other authors fitting their works in around his.

The novel series of the setting (which are far, ''far'' outnumbered by individual novels) include, in rough in-universe chronological order:

* The ''Saga of the Gray Death Legion'' trilogy (Creator/WilliamHKeithJr)
* The ''Warrior'' trilogy (Stackpole)
* The ''Blood of Kerensky'' trilogy (Stackpole)
* The ''Legend of the Jade Phoenix'' trilogy (Robert Thurston)
* The ''Twilight of the Clans'' series (multiple authors, including Stackpole and Thurston)
* The ''Capellan Solution'' duology (Loren L. Coleman)
* The ''Fortress Republic'' duology (Coleman)

In addition, [=FASA=] licensed a number of video game series based on the universe. These, especially the VideoGame/MechWarrior series, turned out to be widely popular, and drew more people into the franchise.

The video games include:

* The ''VideoGame/MechWarrior'' series
* The ''VideoGame/MechCommander'' series
* The ''VideoGame/MechAssault'' series
* ''[[http://mwomercs.com MechWarrior Online]]''
* ''[[http://mwtactics.com MechWarrior Tactics]]'' -- the first ''commercial'' implementation of the boardgame rules

On top of all of this, 1994 saw the release of the AnimatedAdaptation, [[NamesTheSame also called]] ''[=BattleTech=]''. Set during the war against the Clans, it focused on a military unit led by Adam Steiner. It was later {{RetCon}}ned as being a [[LiteraryAgentHypothesis propaganda account of events that actually happened]], with Adam Steiner and at least one other character showing up in the novels.

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!!These works [[note]]tropes specific to the video games are listed on their pages[[/note]] provide examples of:
* AbsentAliens: A few novels (most notably ''Far Country'') actually do have aliens. The rest? None.
** For ''Far Country'', the aliens in question live in a system that's only been accessed by humans twice, both in jumpship mishaps that leave the humans stranded there. So they exist, but they can't interact with the rest of the TabletopGame/BattleTech universe.
* AdaptationDecay: The animated series was retconed as an in-universe, "poorly reviewed Anti-Clan propaganda holo-vid".
** A later sourcebook explains it as based on real in-universe events, but suffering among other things from AnachronicOrder due to drawing inspiration from events that hadn't happened ''yet'' in the timeframe depicted.
* AnyoneCanDie: The EU encompasses a time span of over a century; if combat, accidents, or assassinations fails to kill someone, old age will.
* AwesomeMcCoolname: Grayson Death Carlyle.
* BullyingADragon: Novel ''Close Quarters'' has the main character, Cassie, use a bolter on a battlemech to provoke it into chasing her. The metallic ping against the cockpit window is a [[BatmanGambit direct insult to the mechwarrior's arrogance]], which causes them to give chase. She runs through a few buildings before surprising the mech with an electrical attack to the knee joint. The electricity spot-welds the joint, and crashes the mech to on the ground. She repeats the same action later in the novel by attracting a mech into swampy terrain where it gets stuck and crashes onto the ground.
* CanonDiscontinuity: The [=BattleTech=] Animated Series, as described above. However, some characters, notably Adam Steiner, became {{Canon Immigrant}}s.
* CanonImmigrant: As mentioned above, some of the Animated Series characters obtained this status. Adam Steiner is easily the most visible of them. Also of note are Vandervahn Chistu (Nicolai Malthus' superior) and Franklin Sakamoto. Chistu would briefly become one of the Falcon clan Kahns, ultimately dying at Vlad Ward's hands during the Refusal War. Sakamoto, on the other hand, would survive until the early stages of the Jihad in 3070. (Worth noting that Sakamoto was captured by the Black Dragon forces, with his ultimate fate apparently remaining unknown.)
* CatchPhrase: From the cartoon: "Information is Ammunition." (Also featured in passing as a MythologyGag in the novels)
** Also from the game itself: "No Guts, No Galaxy"
* ChangelingFantasy: Subverted - Franklin Sakamoto renounced his claim to the throne.
* TheChessmaster: Subhash Indrahar, head of the Kuritas SecretPolice for ''60'' years.
* ConspicuousCG: The cartoon's very poorly done [=BattleMech=] rendering sequences. Though they at least got the ponderous weight of 'Mechs right. The animated 'Mech combat looks like anime-style movement.
* CriticalExistenceFailure: The concept of Combat Loss Grouping; stastistically, mechs of a similar weight class will continue to fight for long periods of time before becoming combat ineffective all at once.
* CutShort: The animated series ended on an unresolved CliffHanger. While the novels reveal that the main characters went their separate ways (for example Adam Steiner and Franklin Sakamoto returned to their home nations), the fate of Somerset's populace has remained a mystery.
* DefeatMeansFriendship: A common method for mercenary units looking to recruit people.
* DefectorFromDecadence: [[spoiler: Trent of Clan Smoke Jaguar. Having been a victim of politics several times (his sibmate changes the official report of the battle of Tukayyid, and then manages to steal his spot on the Trial of Bloodright), with the help of his bondsman (who is actually a deep-cover [=ComStar=] spy), he manages to escape his Clan, goes to [=ComStar=] and gives them the Exodus Road, the path to the Clan homeworlds.]] His defection seals the fate of the Clan whom mistreated him, as it leads to Operations Bulldog and Serpent, the annihilation of Clan Smoke Jaguar, and then the Great Refusal which repudiates the entire Clan Invasion.
* DysfunctionJunction: The Seventeenth Recon Regiment, aka "Camacho's Caballeros". Their top scout is a recovering sociopath, one of their best captains is a repeated rape victim, another is clinically insane (and proud of it), and their commander is grieving his deceased daughter while his surviving son suffers from WellDoneSonGuy.
* EntertaininglyWrong: When Anastasius Focht first receives the recordings of Phelan Kell's first battle with the Clans, he dismisses the popular (and correct) hypothesis that they are Aleksandr Kerensky's Star League Defense Force returning to the Inner Sphere, since their 'Mech designs bear no resemblance to Star League-era 'Mechs. Instead, he believes them to be aliens that can assimilate genetic material and self-evolve, first absorbing humans (the SLDF) then improving on the human form to better handle the rigors of 'Mech piloting. He believes that the aliens are invading because in assimilating humanity they have become human, and the Inner Sphere has the best worlds for supporting human life. . . or that they have come to harvest humanity for more raw genetic material to absorb. Some of his conclusions are actually fairly spot-on, though (see RightForTheWrongReasons, below).
* EverythingsLouderWithBagpipes: The Northwind Highlanders have their bagpipe band play the loudest song possible onto Clan Smoke Jaguar radio frequencies to jam up the Clan's communications, forcing the Clanners to use more troublesome line of sight based communications.
* ExactWords: When Hanse Davion and Theodore Kurita make an impromptu but very honorable promise to work together against the Clans. Neither one will send their force into the other's territory so long as the Clans remain a threat. [[spoiler: When the Smoke Jaguars and Nova Cats team up to try and take Luthien, the Draconis Combine homeworld, Hanse has visions of attacking the Combine from his border and finally taking down his nation's most hated enemy. But he promised he wouldn't send his troops into the Combine. On the eve of the attack, the three best mercenary companies in the Inner Sphere arrive at Luthien to shore up their defenses, paid for by Hanse Davion. He still didn't send ''his'' troops into Theodore's territory. . .]]
* {{Expy}}: Johnny Tchang is a straight one of both Creator/BruceLee ''and'' Creator/JackieChan. One of his films is even called ''[[Film/EnterTheDragon Exit The Dragon]]''.
* FakingTheDead: Galen Cox. [[spoiler:It's part of an elaborate scheme to expose Katherine Steiner-Davion's duplicity.]]
* FriendlyEnemy: Hanse Davion and Theodore Kurita get along much more swimmingly than their sons (initially) do at the 3051 Outreach Summit, since their historic family animosities have had time to simmer down with age (and because the [[EnemyMine gravity of the Clan threat]] is much more apparent to them due to their greater experience at statecraft). They're both also honorable (in their own way) and regard each other as [[WorthyOpponent worthy opponents]], and have respect for each other's military and political skills.
* GoodColorsEvilColors: Inverted in the animated series, under enhanced imaging Clanners look green while the Inner Sphere are red. Presumably because it's Clan tech that the "good guys" didn't have access to until halfway through the series. Plus, even with the simplifying of the setting's morality, it's not too hard to see that the Clans do see themselves as the "good guys".
* GoodIsNotNice: Again, too many to list. GrayAndGrayMorality is a big part of life in the Inner Sphere.
* TheGreatestStoryNeverTold: The fate of Clan Wolverine, as chronicled in ''Betrayal of Ideals''. Within Clan society, the story of their downfall, if it is discussed at all, is [[WrittenByTheWinners a heavily biased version]] in which blame for all atrocities is placed squarely on the Wolverines, and any hint that the clan may have survived beyond the level of individual escapees is heavily suppressed. From the Inner Sphere's perspective, the very existence of Clan Wolverine is known only in the context sudden appearance - and equally sudden disappearance - of the mysterious "Minnesota Tribe". Even on a meta level, what happened to the remnants of the Wolverines after their expulsion from Clan society remains unknown beyond the vaguest of hints at their survival until at least the late 3040s.
* GuileHero: Adam Steiner, who in the animated series, considers accurate intel to be the most powerful weapon around and isn't above manipulating rival clans into fighting each other while his crew quietly escape.
* HappilyMarried: Hanse might have married Melissa for political reasons, they did make it work and love each other.
* HeelFaceRevolvingDoor: Tormano Liao. Basically, he's on whatever side is against the Capellan Confederation at the moment.
* HonorBeforeReason:
** Common with the Clan warriors and the older-line Draconis Combine warriors and nobility.
** Also, this is why Myndo Waterly thinks that Anastasius Focht won't [[VillainBall just shoot her]]. [[spoiler:She's wrong.]]
* HypercompetentSidekick: Galen Cox for Victor Davion and Shin Yodama for Hohiro Kurita. Both Great House scions owe their lives more than a few times over to their aides, and consider them indispensible and close friends. In one example, during the Outreach Summit to educate the House Lords about the Clans, the House-Lord-Heirs-Trapped-With-A-Bomb scenario resulted in everyone except Galen and Shin degenerating into expressing centuries-old animosities, while those two worked together under the din to attempt to defuse it.
* ImpossiblyGracefulGiant: The first [=BattleTech=] novels had mechs doing rolls, going prone, and doing other silly maneuvers. Later novels makes them much more [[WalkingTank tank-y]] like in the boardgame.
* KillItWithFire: One of the most effective anti-Mech weapons an infantryman can carry is the Inferno rocket, which is loaded with a napalm substitute that overheats the Mech and cooks the pilot inside. As a result, fear of death by fire is common among [=MechWarriors=].
* KilledOffForReal: Takashi Kurita, Subhash Indrahar, [[spoiler:Omi Kurita]]
* LeftHanging: The final episode of the animated series ends on Adam Steiner and archenemy Nicolai Malthus of Clan Jade Falcon fighting it out for possession of planet Somerset. Steiner wins, [[ExactWords but because he only specifically named the planet itself as the stakes for their duel]], the Clan withdraws from Somerset while taking the locals with them as POW's. This set up a second season that never came.
* ManipulativeBitch: Katherine "Katrina" Steiner-Davion. [[spoiler:For example, she seizes control of an entire interstellar nation just by rigging their popularity polls.]]
* MechaShow: The animated cartoon.
* MediumBlending: The TV series did most scenes in traditional animation but th 'Mech fights were mostly rendered in CG, explained away in-show with it being the advanced targeting displays on Clan 'Mechs.
* MemeticBadass: In-universe, Kai Allard-Liao, especially to the Jade Falcons. First, on Twycross, he obliterated an entire cluster of frontline Falcon mechwarriors in a trap that nearly failed and only went off when he [[SelfDestructMechanism lights his own mech off to detonate the trap]]. Then, on Alyina, he singlehandedly extricates Victor Davion from a trap during a battle against the Falcons gone horribly wrong while his AceCustom mech was in a LimitBreak state. It got to the point where Star Captain Taman Malthus, a Clan Jade Falcon garrison commander, thinks sending fifty [[SuperSoldier Elementals]] in full [[PoweredArmor Battle Armor]] to hunt him down (while he's injured, without a 'Mech, and on the run behind enemy lines), is considered a "fair fight". Since, at the time, Malthus and [[WorthyOpponent Kai]] were ensnared in [=ComStar=]'s "[[LetNoCrisisGoToWaste Operation Scorpion]]" treachery, it made Malthus open to a [[EnemyMine temporary alliance]].
* NamesToRunAwayFromReallyFast: Ninyu Kerai. Subhash Indrahar apparently used to be one before old age caught up with him.
* NiceJobFixingItVillain: In ''Mercenary's Star'', [[spoiler: a Kurita assassination attempt on a Lyran ambassador is exactly what convinces said ambassador to send reinforcements to the Gray Death Legion]].
* OpeningNarration: The cartoon series had one before every episode to give the viewer a bit of a foot in to the extremely elaborate setting.
* ThePlan: Just like being a badass seems to be a requirement for surviving warfare, mastering gambits seems to be required for successfully holding any kind of political power.
* RightForTheWrongReasons: After Anastasius Focht comes to the conclusion [[EntertaininglyWrong that the Clans are actually aliens imitating humanity,]] he reasons that their only interaction with human culture would have been through the warriors of the Star League Defense Force, and they would have developed a society that venerates warfare to an almost religious degree, which is a pretty apt summation of the Clans as a whole. He also believes that gambling, carousing, and braggadocio would be held as nearly sacred arts. While Clansmen neither gamble nor carouse especially, they ''are'' quite boastful.
* RoyallyScrewedUp: Both the Liaos [[spoiler:until Sun-Tzu]] and the Kuritas [[spoiler:until Theodore]] are this.
* RuleOfCool: The actual rules of the original game frequently get tossed aside in favor of this. Hey, [[TropesAreTools whatever works...]]
** Some of these incidents, such as an Atlas throwing the much smaller Locust around like a rag doll (often alluded to in fluff) were [[AscendedFanon finally canonized as game rules to get players to stop complaining about not being able to do what was in the fiction.]]
** Also subverted; the climatic action sequence of '''Grave Covenant''' and most of the 'Mech combat sequences that don't involve Morgan Kell or Yorinaga Kurita in the Warrior Trilogy appear to have been actually gamed out under the tabletop rules. The '''Grave Covenant''' scene with Victor's ''Daishi'' and Renny Sanderlin's ''Penetrator'' is even in one of the scenario books.
* SirSwearsalot: Clan pilots. Expect Clan character's dialogue to be about 20% cussing (in the Clan's vocabulary, which means loads and loads of "FREEBIRTH" and "STRAVAG" being yelled). There's a fair bit of this in the animated series too, since the insults and cusses weren't real words and thus censors had nothing to complain about.
** The Clans consider Natasha Kerensky to be this because of her frequent use of contractions.
* StarCrossedLovers: Justin Allard and Candace Liao (who end up HappilyMarried and produced the aforementioned MemeticBadass Kai), and later Victor Steiner-Davion and Omi Kurita ([[spoiler:which doesn't end nearly as well]]).
* StockholmSyndrome: [=POWs=] of the Clans start out as bondsmen, but are given the chance to regain their warrior status if they pass a TrialByCombat, upon which they become a fully fledged member of the capturing Clan. The most extreme example would be [[http://www.sarna.net/wiki/Phelan_Kell Phelan Kell]] a captured Inner Sphere mercenary (the Clans viewed these as the lowest form of scum) who not only earned his own bloodname (and by that, I mean he had a bloodname ''named after him''), but would go on to become the leader an entire Clan subfaction. Not terribly surprising, given who his father was.
* StoryArc: Done by the animated series, which was noteworthy for American animation of the time.
* TheReasonYouSuckSpeech: Several from various characters at various times.
** Kai Allard-Liao, of all people, drops quite the humdinger on Hohiro Kurita when all the Great Houses are gathered on Outreach to discuss the Clan Invasion. Hohiro is upset because he's noticed Victor Steiner-Davion, his archrival, and Omi, his sister, noticing each other, and can't find either of them. Kai spells out for Hohiro that first of all, he doesn't have to worry about Victor behaving in an "ungentlemanly" fashion with Omi, and that they should be allowed to be friends since it just might help curb the endless warfare the Inner Sphere has lived in for the last 300 years, and moreover if Hohiro and Victor would deign to give each other the time of day, they might actually be able to become friends, to say nothing of actual allies against the Clans instead of constantly trying to one-up each other in the training exercises. All Hohiro can do in reply is to gracefully and politely apologize to Kai for essentially being a shithead.
* TheReveal: The history of the Clans, and the nature of Wolf's Dragoons.
* UnclePennybags: Chandrasekhar Kurita, a lesser known eccentric member of House Kurita, the ruling family of the Draconis Combine. He comes complete with an "Uncle" Honorific in his nickname, "Uncle Chandy". Whereas most men of the Kurita family were austere and militaristic, Chandrasekhar opted for a more hedonistic lifestyle. He still has a strong political and business acumen, as he is one of the wealthiest men in the Draconis Combine. Uncle Chandy's contribution to the Combine's well-being is acting as a sort of independent spymaster, with particular interest in opposing the [[EvilReactionary Black Dragon Society]] (which is to his favorite "nephew" Theodore's benefit since Teddy is quite progressive).
* UnresolvedSexualTension: Kai Allard-Liao and Deirdre Lear. [[spoiler: That would be until they got married. Or possibly earlier.]]
** [[spoiler: Their son, David Lear, was born shortly after they separated on Alyina, long before they got married. Kai was ''unaware he had a son'' for a while. So definitely earlier.]]
** Also a very "star-crossed lovers" example in Victor Steiner-Davion and Omi Kurita. They fall in love with each other at just about first sight when meeting on Outreach, but he's the heir to the Federated Commonwealth and she's the daughter of the Coordinator of the Draconis Combine and they're both too conscientious to just shirk their responsibilities in the name of romance... [[spoiler:They do get together in the end, although eventually an assassin sees to it that it doesn't last forever. One legacy of their romance remains: their son [[MeaningfulName Kitsune]] [[LukeYouAreMyFather Kurita]].]]
* YamatoNadeshiko: Basically Omi Kurita's job description, as she's intended to be Keeper of the House Honor. She fits the role to perfection and then some.

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