[[StargateSG1/AToF Tropes A-F]] | '''Tropes G-L''' | [[StargateSG1/MToR Tropes M-R]] | [[StargateSG1/SToZ Tropes S-Z]] | [[YMMV/StargateSG1 YMMV]] | [[ShoutOut/StargateSG1 Shout Outs]]
----
!!!''Series/StargateSG1'' provides examples of the following tropes:

[[foldercontrol]]

[[folder:G]]
* GalacticConqueror:
** The Goa'uld as a whole already control most of the Milky Way Galaxy, but the most ambitious Goa'uld [[EvilOverlord System Lords]] usually try to conquer all of the galaxy by absorbing the territories of their rivals, assuming the BigBad mantle in the process. Successively, Apophis, Anubis, and Ba'al came the closest to actually succeeding.
** As well as the Ori, who have already conquered one galaxy. They're [[AscendToAHigherPlaneOfExistence ascended]] EnergyBeings who rule through a ReligionOfEvil called Origin, and build an armada to embark on a crusade to convert the Milky Way.
* GasLeakCoverup: Standard for secret government operations, and usually plausible. A notable exception was when the government used the actual "gas explosion" explanation for a building being teleported out of downtown Seattle, in one of the final seasons. The complete lack of any blast or debris was quickly called out.
* GenreSavvy: The series wouldn't be the same without it.
** Pretty much the whole team.
--->'''O'Neill:''' [[DisasterMovie I've seen]] [[Film/{{Armageddon}} this movie]]. [[DeathFromAbove It hits]] [[ThrowAwayCountry Paris]].
** Played for many laughs in "200".
--->'''Teal'c:''' I do not understand why everything in this script [[StuffBlowingUp must inevitably explode]].\\
'''Marty:''' Trust me. Explosions [[NeverTrustATrailer make great trailers]].
** Also...
--->'''Marty:''' I'm talking about... [[TwistEnding a twist]]! Something nobody's expecting!\\
'''Jack:''' (''enters after being {{put on a bus}} for many episodes'') You mean something like this?\\
'''Vala:''' Wow, [[DidntSeeThatComing I don't think anybody will see that coming.]]\\
'''Daniel:''' Nope, there'll be {{spoiler}}s.\\
'''Carter:''' Are you kidding? [[TrailersAlwaysSpoil It'll be in the commercial]].
** And it should be noted that both [[LampshadeHanging Jack]] and the [[EarthShatteringKaboom explosion scenes]] were included in the SciFiChannel commercials for said episode.
** From "Point of View":
--->'''Doctor Samantha Carter:''' Well if you're not gonna give us a second chance... I don't know any of you.\\
'''Jack:''' Well, exactly -- you don't know any of us. And we don't know you. For all we know, you could be her evil twin! But then we'd be dealing with clichés, and you know how I feel about those.\\
(''turns to Major Carter from his reality'')\\
'''Jack:''' No, actually ''you'' know how I feel about them.
* GetBackToTheFuture: The plot of "1969" and "Moebius".
* GettingCrapPastTheRadar:
** "Deadman Switch":
--->'''Aris Boch:''' And you, O'Neill, you're considered, well you're a pain in the ''[[PardonMyKlingon nik'tah]]''.\\
'''O'Neill:''' Neck?\\
'''Teal'c:''' No.
** Jack in "Absolute Power".
--->'''Shifu:''' A spark lights a flame, but the candle will burn only as long as the wick.\\
'''Jack:''' If I may sir, I think what he means is, the wick is the centre of the candle, and obstensively a great leader, like yourself, is essential to the whole ball of wax. Basically what it means is is that its better to have a ''big... long... wick'' right?
* GhostCity: In "Bane", "Ascension", "2001", and "Menace".
* GirlishPigtails: Worn by Vala on occasion.
* GiveMeLibertyOrGiveMeDeath: The Jaffa rebellion.
* GlowingEyesOfDoom: The Goa'uld (and Tok'ra) can make their host's eyes glow on command, which they often do [[RuleOfDrama at critical points in the story]]. They also tend to do it by reflex when just taking over a new host, or when dying.
* GoalOrientedEvolution: Averted in the initial seasons, where scientists find the idea of duplicate evolution of genetically compatible species to be completely unbelievable, and Ascension is a philosophical concept, unconnected to evolution in any way. However, towards the end of the series, and especially after the Ori are introduced in season nine, humans are explicitly described as evolving on "a path to Ascension," which has been repeated with at least ''four'' different branches of humanity that evolved independent of one another (the Ancients, humans of the Milky Way, humans of the Pegasus Galaxy, and the humans of the Ori Galaxy). Eventually, people can ''only'' Ascend at the conclusion of their "natural" evolution.
* AGodAmI:
** The Goa'uld take on the persona of gods of Earth's early mythologies. Some of the more deluded, such as Ra, Anubis, and Apophis, seem to buy into their own hype and actually believe themselves to be gods, while others, like Ba'al or Nerus, are aware that the Goa'uld are just parasitic snakes and only play the role of being divine to maintain their power.
** The Asgard use holograms to depict themselves as the gods of the Norse pantheon, but only to primitive peoples under their protection who would not understand the concept of "aliens". They include tests within their "religious" sites to let them know when the population is ready to hear the truth.
* GodEmperor / GodGuise: Standard Goa'uld PR theme. Sufficiently advanced technology makes it easy for them to pass as classical pantheonic gods, and thanks to their ridiculous egos and the mind-screwery of the sarcophagi some of them even believe it themselves.
* AGodIAmNot: The ascended Ancients refuse to be worshipped or thought of as gods. The Ori on the other hand...
* GodsNeedPrayerBadly: The Ori manage to sap power from their worshipers, which is why they foster the religion of Origin.
* GodTest: When Gerak becomes a Prior of the Ori and is asked to destroy Jaffa who refuse to believe, Teal'c asks him what makes him believe they are gods, citing various impressive miracles they could have performed. He then points out that the Goa'uld performed ''the exact same miracles'' and posits that the measure of a god is not how much power they have, but how they apply it. If they were gods, they would not need Gerak to kill anyone on their behalf, or even ask such a thing of him.
* GoingDownWithTheShip:
** [[spoiler:Colonel Lionel Pendergast aboard the ''Prometheus'', who stays aboard to make sure that his crew can evacuate down to the planet surface.]]
** General Hammond fully expects this to happen in "Fail Safe". He's evacuated the entire SGC to the Alpha Site, but opts to remain behind himself, as he's "not been relieved of this command".
* GoingNative: While it largely happened [[TheyWastedAPerfectlyGoodPlot offscreen]], later series show Teal'c had become very fond of Earth culture.
* GoMadFromTheRevelation: Pretty much the reason for keeping the program quiet. In ''almost'' every parallel universe they visit where the program has gone public [[PowderKegCrowd things go downhill fast]]. On the other hand, in many realities this wasn't so much because TheWorldIsNotReady, but more because Earth became a TerminallyDependentSociety on Stargate travel and using powerful alien allies for defence, at the expense of advancing their ''own'' technology to keep an edge.
* GoodBadBug: An in-universe example, where when Replicator [[VisualPun bugs]] take over a Goa'uld ship, they cause a security breach that allows our heroes to escape a room they had been locked in.
* GoodOldWays: {{Inverted|Trope}}; Teal'c, Bra'tac and other recurring Jaffa characters spend much of their time struggling to get the Jaffa to abandon their old traditions, since most of them were fostered by the Goa'uld. These include [[NoWomansLand a lack of sexual equality]] and [[MightMakesRight a government based on military assets]].
* GoshDangItToHeck: When particularly annoyed, Mitchell will exclaim "Mary and Joseph!"
* GrammarNazi: Ironically, O'Neill does this often. Even while being tortured, he corrects the villain's grammar.
-->'''Her'ak:''' No matter what you have endured, you have never experienced the likes of what Anubis is capable of!\\
'''O'Neill:''' You ended that sentence with a ''preposition''... bastard!
* GrandTheftMe: This was Machello's motive for causing the aforementioned FreakyFridayFlip in "Holiday".
* GreenAesop: In "Revisions", the planet's atmosphere is completely unbreatheable due to industrial pollution.
* GreenSkinnedSpaceBabe: Anise/Freya of the Tok'ra is a sexy female alien with sexual tension with both Daniel Jackson ''and'' Jack O'Neill (Freya, the host, likes Jack, but Anise, the symbiote, likes Daniel).
* GroundhogDayLoop: The mostly-comedic "Window of Opportunity" episode, a fan favorite.
* TheGuardsMustBeCrazy: For once the bad guys do not hold a monopoly on this trope, as incompetence is the general order of guards in the SG-1 universe.
** When the Tok'ra are planning to surgically remove the Goa'uld Tanith from his host, he claims that he would rather die and take the host with him. He convulses and collapses to the ground and his two guards, with a third Tok'ra present, open his cell to check on him. Though they are armed, specifically with weapons that are non-fatal and can be used even against a human shield, Tanith is able to grab one by the throat and escape. Perhaps because the writers could not think of a way to show this without having the Tok'ra appear ''completely'' incompetent, the scene cut away after he grabbed the first guard. O'Neill subsequently lampshades just how incompetent they must have been to let him escape.
** When Teal'c has been brainwashed into once again serving Apophis, he captures O'Neill, Carter and Daniel and locks them in a room aboard a ha'tak, whereupon Selmak/Jacob breaks them out because there were no guards stationed there... [[SubvertedTrope which was the entire point, since Teal'c wanted to capture Selmak/Jacob, too, and needed an adequate lure]]. Apparently Teal'c is so badass that he actually ''is'' a competent guard.
* GunsAkimbo:
** In the Season 1 finale, to rescue Jack and Teal'c, Daniel takes Sam's sidearm and goes Akimbo while Sam uses the [=MP5=]. Later, he wields the Beretta M9 sidearm in one hand and the [=MP5=] in the other. Granted, at that point he was just spraying and praying.
** In "Seth", Jack, Sam, and Daniel do this with a pair each of zat'nik'tels.
** In "200", Mitchell pitches a ZombieApocalypse story that features him wielding two SMG's.
** Teal'c has, throughout the series, operated two staff weapons and even two P90's. While this is never his standard equipment, when things get desperate he'll routinely pick up a second weapon (in the case of staff weapons, from an enemy Jaffa he's just killed) and wield both with great effectiveness.
[[/folder]]

[[folder:H]]
* HalfHumanHybrid:
** Three episodes features humans with Goa'uld DNA. The first is a ''harcesis'', a child born of two Goa'uld hosts. The second is an experiment by Ex-NID operatives to gain access to the Goa'uld genetic memory. The third is a clone created by [[BigBad Anubis]], designed to evolve until it's capable of [[AscendToAHigherPlaneOfExistence ascension]]; he was a prototype of a new army Anubis was going to create to ''kill the Ancients''.
** The Serrakin -- a race capable of breeding with humans despite ''not'' being HumanAliens. They had liberated the humans of their system from the Goa'uld millennia ago and the two species now co-exist in a mixed society.
** Adria is a human with the knowledge of the Ori bred into her DNA. She is described as an Ori in human form, their way of getting one of their own into the Milky Way without technically violating the rules the Ancients have against directly interfering.
* HandBlast: The Goa'uld hand device, useful for energy pulse attacks and brain scrambling.
* HappilyAdopted: Dr. Fraiser took in Cassandra, a young girl whose planet had been wiped out by Nirrti in the first season, and raised her lovingly as a daughter. However, when Cassandra returns in the fifth season she is now a teenager and, like all teenagers, [[DeconstructedTrope is butting heads with her mother over dating, family dinners and other aspects of maturation]].
* HardLight: Merlin shows an extreme fondness for hard light constructs, using them as the guardians and tests of his various workshops. SG-1 has had to face two knights and a dragon in order to prove themselves worthy of his knowledge.
* HashHouseLingo: Oma Desala in "Threads".
* HeelFaceTurn:
** Teal'c, right in the first episode.
** Aris Boch seems to have a change of heart, realizing that SG-1's fight against the Goa'uld is a worthy venture.
** Harry Maybourne went from enemy to ''convicted US traitor'' to useful asset to grudging ally and friend. Eventually SG-1 even relocates Maybourne offworld to protect him from punishment for his original crimes.
** Richard Woolsey, first an agent of Senator/Vice President Kinsey and the [=NID=], then digs up information to incriminate Kinsey after getting a peek at his [[ManipulativeBastard true nature]]. Notable for ''remaining'' a committed bureaucrat (though a relatively less [[ObstructiveBureaucrat obstructive]] one) after his change of allegiance.
* HeelRaceTurn: The Jaffa are the prime example, although due to the [[Series/StarTrekTheOriginalSeries Kirk-like]] influence the team tends to have on certain worlds, there are certainly plenty of minor examples.
* HeelRealization:
** In "Bane", Dr. Timothy Harlow realizes ''mid-sentence'' that Colonel Maybourne is not just willing to take unscrupulous shortcuts, but is actually planning to ''let Teal'c be transformed'', and that by calling him in for assistance he has doomed Teal'c to a painful death.
** In "Inauguration", Mr. Woolsey begins to realize that his superiors might not be as honorable as he believed when his conversation with Vice President Kinsey seems to end with the implication that Kinsey is going to ''assassinate the president'' if he does not get his way.
** In "Holiday", when Daniel makes Machello realise that by [[BodySurf stealing his body]], he's [[HeWhoFightsMonsters become just as bad]] as the Goa'uld he's spent his entire life fighting.
--->'''Daniel:''' You're a ''[[NotSoDifferent Goa'uld]]'', Machello!
* HeroicResolve: Mitchell was badly beaten by Merlin's holographic knight in "Avalon", but was able to gain a new reserve of strength when he thought back to how he refused to give up after he was injured when his F-302 was shot down over Antarctica. Since the knight is more of a [[OnlyTheWorthyMayPass test]] than an actual enemy, he defeats it and gains access to the riches and technology of Merlin.
* HeroicSacrifice:
** During "In the Line of Duty", the Tok'ra infesting Sam decides to let itself die so that Sam wouldn't have to die with it.
** Subverted at the climax of "Lost City". The ''Prometheus'' and her fighters are out of ammunition and her shields are failing, so Hammond orders the ship onto a collision course with Anubis' flagship, saying [[TakingYouWithMe "We go, they go."]] [[spoiler:The Ancient outpost's drones get there first and Hammond breaks off.]]
** [[spoiler:Gerak]] knew that turning against the Ori would mean his immediate death, but still chose to help cure the Prior plague that was ravaging the Earth.
--->'''[[spoiler:Gerak]]:''' If I do this, I will die. But [[IDieFree I will die free!]]
** In "Lockdown", Colonel Vaselov forces Anubis to take his (dying) body through the Stargate, saving O'Neill in the process.
* HeroOfAnotherStory:
** Colonel Makepeace, formerly the TropeNamer.
** Colonel Reynolds after Makepeace is [[spoiler:revealed to be TheMole]].
** Cameron Mitchell before joining the main cast, where flashback's reveal he was part of Hammond's defence force at the Battle of Antartica and spent the next year in traction, undergoing physical therapy, due to injuries received when his F-302 crashed.
* HeroWorshipper:
** Felger to SG-1, [[IrritationIsTheSincerestFormOfFlattery much to Col. O'Neill's chagrin.]]
** Lieutenant Colonel Cameron Mitchell starts season nine almost ''obsessed'' with working with SG-1. When he learns that he is actually going to be in command of the unit since all its prior members have been reassigned, he [[PuttingTheBandBackTogether gets the band back together]] because he specifically wants to work with those three people.
%% HeyItsThatGuy is trivia and go in the Trivia tab.
* HideYourPregnancy:
** Amanda Tapping was pregnant throughout the end of Season Eight, with her stomach hidden with the traditional practices of obstructing objects and dark, black clothing. She was on maternity leave when filming began for Season 9, leading to Carter being temporarily assigned to Area 51.
** Lexa Doig became pregnant with her and husband Michael Shanks' second child during filming for Season 10, resulting in her character of Dr. Carolyn Lam having a greatly reduced presence and all but disappearing from the show.
* HijackedByGanon: In season 8, [[spoiler:Ba'al takes control of Anubis's remaining forces after the destruction of Anubis's fleet during the invasion of Earth, and uses his superior [[SuperSoldier Kull Warriors]] to successfully wage war on all the other Goa'uld combined. Anubis reappears on Earth, but gets stuck on a frozen planet in a host body. At the end of the first part of "Reckoning", Ba'al reveals to O'Neill that Anubis is back in command of the largest Goa'uld faction, and that he was serving him for a while now.]]
* HippieBus: In episode "1969" the SG 1 team accidentally travels back to the year 1969. They have to find the Stargate and end up hitchhiking with a hippie couple (on their way to a concert in Woodstock) driving a hippie painted school bus.
* HistoryRepeats:
** "Spirits" revolves around a plan by the US Government to surreptitiously mine trinium from a planet inhabited by descendants of the North American Salish. When they learn of this, SG-1 is ''very'' upset over the repetition of the early history of the United States, and explicitly points out that we were supposed to have learned from our mistakes.
** "Enemy Mine" has a similar plot, with the Unas in stead of the Native Americans on a planet sporting a naquadah mine. Daniel's diplomatic skills manage to save the day, quite luckily -- because otherwise, the history repeat would have been of ''Little Big Horn''.
* HolodeckMalfunction: The episode "Avatar".
* HologramProjectionImperfection: Asgard holograms look incredibly realistic most of the time, but occasionally wobble or fritz just enough to let us know it's a hologram.
* HonorBeforeReason: The Ascended Ancients have as their primary philosophy a policy of non-interference amongst the lower planes of existence. They believe in this so strongly that they will not interfere when the Ori, their hated enemies who are planning their destruction, manipulate the lower planes in order to increase their own power, nor even when the inhabitants of the lower planes gain a weapon ''to kill Ascended beings''. As Morgan Le Fay explains, if they interfere then they will be no better than the Ori and most of them would rather ''die'' than interfere.
* HostageSituation: In "Bad Guys", SG-1 is mistaken for a group of rebels on an alien planet and wind up taking a museum hostage. They realize that if they just let all the hostages go the military that surrounded the museum will storm in and kill them all, so they decide to hold on to the hostages until they can get the Stargate working and gate off the planet. Unfortunately, the people in charge of the besieging forces seem to have no clue how to run a hostage negotiation, Daniel seems to have no clue how to play a hostage-taking terrorist, and there's a security guard who thinks he's [[Film/DieHard John McClane]], so HilarityEnsues.
* HostileTerraforming: "Scorched Earth" features an alien {{terraform}}ing ship that is replacing the ecology of an Earthlike planet with a sulfur-based biosphere. Only trouble is, the SGC has just relocated some HumanAliens onto the planet who need its thicker-than-usual ozone layer. [[spoiler:The trouble is resolved when the Daniel discovers that the ship knows where the HumanAliens' original homeworld is.]]
* HotScientist: Sam Carter
* HowDareYouDieOnMe:
** When O'Neill is fading away at the end of "Lost City", Carter says that he cannot die ''now'', they just won.
** Also in "Holiday" with Sam and Daniel:
--->'''Sam:''' Come on, Daniel. They've found the guy, they're bringing him in. You have to wake up. (''she moves over to hold his hand'') Daniel. You can't die on me now.\\
'''Daniel:''' (''weakly'') It's nice to know you don't just like me for my looks.
* HumanAliens:
** TransplantedHumans for the most part, except for the Ancients, [[{{Panspermia}} who came first and arranged for the Tau'ri to look like them after they left.]]
** The Nox are woodland creatures that appear human with leaves and twigs in their hair. The reason why they look almost human is never explained.
** The Jaffa are a genetic offshoot of humanity created by the Goa'uld. They are biologically human in most respects, except they have an abdominal pouch which is used to incubate larval Goa'ld; the Goa'uld larva in turn grants the Jaffa immunity from disease and an increased lifespan, but cannot be removed without condemning the Jaffa, as they lack an immune system of their own.
* HumansAreSpecial: Humans (specifically, the Tau'ri) are not shown to be particularly smarter, stronger, faster or more "imaginative" than other species, but the Asgard point out that they have great ''potential''.
* HumansByAnyOtherName:
** "Tau'ri", meaning "those from the first world", refers to humans from Earth to distinguish them from [[TransplantedHumans all the other humans of the galaxy]].
** The correct way to refer to people from Earth is humourously pondered in "Cure";
--->'''Zenna:''' Earthans?\\
'''Jonas:''' ''Earthlings''... sort of? [...] Well, we're not ''originally'' from there.\\
'''Teal'c:''' But we have dedicated ourselves to the cause of the Tau'ri. (''{{beat}}'') Earth.
** "This form" is (rarely) used to refer to the general human species, to distinguish them from alien species. When the issue of the evolution of the Ancients and the subsequent ''identical'' evolution of humanity is raised, the term "this form" is used to refer to both Ancients and humans, since the technical issue of species classification is somewhat tricky.
* HumanSubspecies: The Jaffa were genetically engineered from mainline humans to serve as incubators for Goa'uld larvae.
* HumorlessAliens:
** O'Neill is distrustful of the Aschen for precisely this reason.
** Also, Teal'c tends to miss the point of O'Neill's jokes. Funnily enough, the trope is also inverted in one episode; Teal'c, with prompting, tells a Jaffa joke that obviously amuses him, but falls flat on its face with the rest of SG-1.
* HurricaneOfPuns:
** The System Lord Yu has been punned so often that characters have actually put a moratorium on further punning, explicitly stopping others and explaining that it has all been done before.
** When Ba'al begins cloning himself, Ba'al-related puns become quite common:
--->'''Cam:''' We've got a full count, sir. Two strikes, three Ba'als.
* HypocriticalHumor:
** In "Cor-ai" Hammond says to Jack: "The US military is not in the habit of interfering with the affairs of other peoples." Jack just sort of looks at him and then at Carter and says, "Since when?"
** In "Disclosure" the Chinese representative says that "The government of China does not believe in keeping secrets from its people." The look Russian representative Col. Chekhov gives him sells it.
[[/folder]]

[[folder:I]]
* IAlwaysWantedToSayThat: Mitchell uses the term "[[TwoOfYourEarthMinutes Earth minutes]]" in "Beachhead", then explains to Daniel that he always wanted to say that.
* ICanSeeMyHouseFromHere: Although in this case it is not to emphasize how high they are, but how relatively ''low'' they are getting.
* ICantBelieveImSayingThis: One of the funniest parts of this series is watching the Very Serious Military Personnel describing or giving orders in absurd situations.
-->'''Hammond:''' What am I supposed to ''say''? (''pulls out microphone'') A glowing energy being is headed for Level 28. Lower your weapons and do not attempt to intercept it.\\\
'''Hammond:''' Okay, people. Let me remind you. This mission is recon only. Do not engage the enemy. I'm allowing the use of this ship because of the obvious tactical advantage it provides you. Under no circumstances is it to be used to travel through time. (''beat'') Never in my life did I imagine ever giving that order.
* IComeInPeace:
-->'''Jack O'Neill:''' We came in peace. We hope to leave in one... piece.
* IdentityAmnesia: The entirety of the planet Vyus suffered this about a year prior to "Past and Present" [[spoiler:due to a MadScientist from a previous episode]].
* IDidWhatIHadToDo: After [[spoiler:Teal'c kills Sha're]] he is sad, but he points out that it was a choice between her life or Daniel's, and if he was in the situation again he would make the same decision.
* IDieFree: TropeCodifier. Rebel Jaffa are frequently heard saying this when threatened by one of the Goa'uld or their followers, or in any other case where they're about to make an act of suicidal defiance.
* IDontLikeTheSoundOfThatPlace: [=P3X=]-[[NumberOfTheBeast 666]]. Notable as the planet where [[spoiler:Dr. Fraiser was killed.]]
* IfIHadANickel: Jack says it in "It's Good to Be King" about hearing, "Surrender your weapons, or die where you stand."
* IfYouDieICallYourStuff: Played for heartwarming. In "The Enemy Within", when they're prepping Kawalsky for surgery to try and remove the Goa'uld larva in his head, Jack asks him, "If you don't make it ... can I have your stereo?" Jack is quite obviously being deliberately silly to try and cheer Kawalsky up.
* IfYouKillHimYouWillBeJustLikeHim:
** In "Cor-ai", Hanno is prepared to kill Teal'c as soon as he sees him, but one of the other villagers convinces him not to go through with it and take Teal'c prisoner for cor-ai (trial). He explains that if Hanno kills him in vengeance, then they will be no better than the Jaffa.
** Subverted in "Bloodlines". After stealing an immature Goa'uld symbiote for the scientists to work on (it ends up replacing Teal'c's symbiote that he gave to his son), Daniel and Carter start to walk away. Daniel stops and takes aim at the tank of symbiotes since he's still raw about Apophis' kidnapping Sha're. Carter says this to Daniel, who seems to be convinced. They start away again, then Daniel suddenly turns around and machine-guns the tank anyway.
* IGaveMyWord: In "Spirits", T'akaya agrees to hear out Daniel and Jack if they show her where Xe'ls is. When Xe'ls awakes he orders T'akaya to destroy the SGC, but she refuses until she has at least heard them out; Xe'ls points out that they have already learned of plans by the SGC to deceive them and that their word is worthless, but T'akaya ''still'' refuses to act, pointing out that her word would be worthless, too, if she broke her own promise.
* IHaveNothingToSayToThat: O'Neill being led into kicking [[{{Mook}} Jaffa]] butt.
* IKnowYoureInThereSomewhereFight: Often when talking to a loved one who has been taken as a host. A recurring question in early episodes was if there ''is'' any part of the host's mind/soul that survives. [[spoiler:There is, and the Goa'uld just suppresses it. At least in the case of a young symbiote with a strong-willed host, it is even possible for the Goa'uld to momentarilly lose control.]]
* IllTakeTwoBeersToo: When the team is under the influence of appetite-increasing phlebotinum.
* IMadeCopies: When General Hammond gives Mr. Woolsey a computer disk with evidence to incriminate Vice-President Kinsey in a conspiracy of blackmail and murder to gain control of the Stargate, he points out that it is not the only copy before Woolsey even asks.
* IMinoredInTropology: When Mitchell has to SwordFight an armored knight, he reassures the rest of SG-1 that he studied fencing in college. When he gets his ass kicked by the knight [[DeconstructedTrope he explains that he]] ''[[DeconstructedTrope failed]]'' [[DeconstructedTrope fencing]]. Luckily, [[OnlyTheWorthyMayPass the knight was more of a test than an enemy]] and he was able to defeat it [[HeroicResolve after he gained a second wind]].
* ImmortalityInducer: The sarcophogi, which can extend the human lifespan to over 1,000 years provided the person has regular access to its healing properties.
* ImMrFuturePopCultureReference: In "1969", while messing with the 1960s interrogator, O'Neill claims that he's [[Franchise/StarTrek Captain James T. Kirk]]. He then later switches to [[Film/StarWars Luke Skywalker]], probably after realizing that Star Trek already existed in 1969.
* ImNotADoctorButIPlayOneOnTV: Parodied in "Fallen":
-->'''Khordib:''' He [Teal'c] is Jaffa.\\
'''O'Neill:''' No. But he plays one on TV.
* ImpaledPalm: O'Neill inflicts this on Heru'ur in "Secrets".
* ImpaledWithExtremePrejudice: [=RepliCarter=]'s preferred method of execution.
* ImperialStormtrooperMarksmanshipAcademy: The Jaffa, although simultaneously justified and {{lampshade}}d in later episodes when Jack explains that the staff weapons are designed to intimidate, while human weapons are designed to kill. Essentially, its really hard to "aim" by pointing a six-foot staff at things. (See KineticWeaponsAreJustBetter below.)
* ImplacableMan: Special note goes to the Kull Warriors, especially the first time SG-1 tries to catch one.
* ImpossiblyMundaneExplanation: In "Window of Opportunity" Jack has prior knowledge of a briefing Carter is giving and claims that he is remembering things from the future. Carter suggests, "Maybe he read my report?" Daniel gives her a skeptical look and repeats, "Maybe he ''read your report''?" as if it was the most ludicrous suggestion. Everyone else (O'Neill included) seems to agree.
* ImpostorExposingTest: In "Foothold", Maybourne cuts himself in front of Carter to prove he's human after an alien impostor is shown to have purple blood.
* ImStandingRightHere:
** Dr. Felger is unsure if O'Neill knows he is there when he calls him a "brown-nosing little weasel". His tone makes it clear that he does not know which answer he would prefer: that O'Neill is talking about him behind his back, or that O'Neill is directly insulting him to his face.
** Vala continuously refers to the SGC's attempts to understand the Goa'uld bracelet bond as pointless, to which Dr. Lee, who is running the tests, points out that he is actually touching her face at the time.
* IncomingHam: "Urgo", featuring Creator/DomDeLuise. Just watch the background characters trying desperately to keep a straight face.
* InconvenientSummons:
** The Asgard love getting a hold of O'Neill this way. Frequently in mid-sentence. The first time, Jack was in the middle of giving a speech when he was teleported; the second time he was in the middle of inviting Carter to go fishing with him.
** The Ori arc made a running gag of this, with one of Earth's ships beaming Daniel Jackson on board from a planet's surface, usually right in the middle of him trying to explain to some villagers that there was no magic, he was not a god, etc.
--->'''Dr. Jackson:''' You are making a mistake. There is no curse. The black knight is a security feature created by Merlin through the use of science and advanced technology. There is no magic-- (''the ''Odyssey'' beams up SG-1'')\\
(''later'')\\
'''Dr. Jackson:''' Once and for all: There was no curse. This is a device. There is no magic-- (''the ''Korolev'' beams him up'')\\
'''Dr. Jackson:''' Boy, my timing's off today...
* IncrediblyLameFun: When Jonas Quinn arrives on Earth, he becomes fascinated by [[MundaneObjectAmazement the Weather Channel]] and watches it for hours, to which Carter responds that here are ''at least'' five hundred other channels.
* InfiniteSupplies: Averted. The inability of the rebel Jaffa to even feed themselves is a recurring problem, as is their lack of weapons and supplies to wage their war. The Hak'tyl, a group of [[AmazonBrigade female Jaffa]] from the domain of Moloch, seek out an alliance with the SGC and offer their services as soldiers, scouts and spies in return for food and support.
* InHarmsWay: Carter is a real adrenaline junkie, and volunteers to take part in a dangerous alien competitive spaceship race in "Space Race". She's also seen tuning up a motorcycle in her spare time, so one can assume she rides it for fun (or regularly).
* InkblotTest: When Vala is being examined for suitability to formally join the SGC, the reviewing doctor has her look at blots, but stops when she tries to game the system by saying that she sees abstract concepts, like "courage", in the blots.
* InnBetweenTheWorlds: The "Astral Diner" of the episode "Threads". The place is a midway point between the mortal dimension and the higher realms where the Ascended live. Played with in that it's actually an example of AFormYouAreComfortableWith, as it was modelled after Daniel Jackson's memories.
* InscrutableAliens: In "Grace", the ''Prometheus'' encounters an alien warship that refuses to respond to hails and opens fire on them. It pursues them into a nebula and abducts all the crew save Sam before they're both trapped by the nebula. [[spoiler:Sam manages to trade a way to get out of the nebula for the crew]], but nothing resembling them is ever encountered again.
* InsectoidAliens: The Reetou, which are invisible to the human eye but can be sensed by a Goa'uld symbiote.
* InSeriesNickname: In the [[ParodyEpisode 200th episode]], Jack's calling the Stargate "old orifice"!
* InsignificantLittleBluePlanet: It turns out Earth played an integral role in the history of the universe, but for the present day and the past few millennia it has been little more than a backwater planet forgotten by the more advanced races.
-->'''Aris Boch:''' Contrary to popular {{human|sAreSpecial}} belief, the Earth is ''[[InsignificantLittleBluePlanet not]]'' [[EarthIsTheCenterOfTheUniverse the center of the galaxy]].
* InsistentTerminology: Robert Kinsey never seems to get the titles of aliens corect.
** In the season six episode "Disclosure" he refers to Thor as "Commander", only to be corrected (with an upraised finger) to ''Supreme'' Commander.
** In the season seven episode "Lost City" he refers to Bra'tac as "Mister Bra'tac", only for O'Neill to point out that it is ''Master'' Bra'tac.
* InSpiteOfANail: We see several {{Alternate Universe}}s, some created by TimeTravel and others reached in other ways. In almost every one, Earth and modern America are indistinguishable from the universe of the Franchise/StargateVerse [[PlausibleDeniability from the point of view of the public]], despite the deviation point occuring decades or even thousands of years ago.
* InstantAwesomeJustAddDragons: One of Merlin's tests.
* InstantSedation: Averted more often than it is played straight.
** In "In the Line of Duty", when Sam/Jolinar gets tranqued twice, the first case with "enough to knock out an elephant," it takes a minute before she is disabled.
** "Spirits" is the one episode where it is played straight; SG-1 is incapacitated by small darts towards the beginning of the episode and collapse almost immediately after being shot.
** In "Redemption, Part 1", Captain Hagman (the 9th temporary replacement for Daniel Jackson) gets hit in the leg by a tranq dart while SG-1 is ChasedByAngryNatives. He has the time to cross the Stargate before falling down, though.
** Osiris is twice shot by a Goa'uld-specific sedative, and in both cases it takes several minutes before it takes effect. In "The Curse" s/he even managed to make good his/her escape before succumbing to the drug.
** In "Memento Mori", Vala is injected with a sedative directly into her carotid artery, and she ''still' does not lose conciousness right away. She becomes unsteady on her feet and unable to talk, and is rushed into a vehicle by her kidnappers.
* InterdimensionalTravelDevice: The Quantum Mirror, which makes a few appearances in early episodes before being destroyed offscreen. In one episode, Daniel accidentally uses it to travel to another universe; in a later episode, alternate-universe versions of Carter and Kowalski come back through it, looking for refuge from the Go'a'uld invasion fleet that just arrived on Earth in their universe.
* IntergenerationalFriendship:
** Teal'c seems to bond with children very readily (not in a creepy way).
*** In "Bane", Ally Martin discovers and helps hide the poisoned Teal'c after he escapes from NID custody. Once he is healed, he returns and gifts her a new super soaker.
*** In "Learning Curve", Teal'c gives Tomin knowledge of the Goa'uld to help defend his society, and becomes almost violent when he is told that Tomin cannot return and suspects that he has been mistreated.
** Also appears with Daniel. In "Birthright", he befriends Nesa, a young Jaffa girl of the Hak'tyl who needs a symbiote. Their friendship goes a long way in finalizing the alliance between the SGC and the Hak'tyl.
* InterserviceRivalry: Between the SG-3 Marines (Jarheads) and the SG-1 Air Force (Flyboys) after the former's introduction in "The Broca Divide". It is [[DownplayedTrope brief]] and does not appear in subsequent episodes.
* InTheBack: [[spoiler:Colonel Simmons]] shoots O'Neill in the back in the climax of "Desperate Measures".
* InTheHood: The standard disguise for SG teams when they want to stay incognito on low-tech planets.
* {{Invisibility}}: In the episode 200, the team reveals that at some point Jack O'Neill was turned invisible. He used it to, among other things, spy on Carter in the shower. Apparently he didn't want to give it up.
* InvisibilityCloak: Various species have devices, mostly working like the natural ability of the Re'tu, by putting the wearer somewhat out of phase with reality. Thus the Transphase Eradication Rod (anti-Re'tu weapon) reveals them.
** Some Goa'uld use them (but not all, as they don't share technology), namely Nirrti, Athor, and an Ashrak assassin (in "Allegiance").
** The Asgard have them too, notably one found on a protected planet in "Shade of Grey".
** The Sodan warriors have their own variant, issued from Ancient technology, which they put to good use. This model have the problem of emitting a radiation that is harmful for humans on the long term (although Jaffa can endure it thanks to their symbiotes). [[spoiler:It is however a necessarily protection measure against some interdimensional parasites otherwise attracted by the users.]]
* InvisibleJerkass: Mocked, as was ''everything'' else, in the infamous episode "200". In a flashback (not seen in the previous episodes), O'Neill becomes invisible due to an alien device. His subsequent pranks include leaving the room so that Carter is left talking to an empty chair, falling asleep and snoring in a room where Daniel is having a meeting, driving up to the base entrance and placing his dog behind the wheel to confuse the soldiers, and spying on Carter when she takes a shower.
* InvisibleMonsters: The series has featured the Re'tu, big spider aliens which are invisible because they are "180 degrees out of phase from normal space-time".
* InvisiblePresident: The President of the United States during the show's first seven seasons, stretching from 1997-2004, was unidentified either by name, image [[NoPartyGiven or party]].
* IResembleThatRemark: Carter's response to being told that she seems tense is to, very tensely, reply that she is not tense.
* ISayWhatISay: The cloned O'Neill in "Fragile Balance".
* IsThisThingOn: In season 8 episode "New Order, Part 2", O'Neill does this while merged with the computer of Thor's spaceship, and talking through its comms.
-->'''Jack's voice:''' Hello. Testing, testing. One, two. One, two, one, two, testing. Helloooo? Is this thing on?
* ITakeOffenseToThatLastOne: In "Citizen Joe":
-->'''Joe Spencer:''' You're Brigadier General Jack O'Neill. Head of Stargate Command at Cheyenne Mountain. You used to command SG-1, which is now led by Lt. Colonel Samantha Carter. You once visited a planet called Argos, and the nanites in your blood caused you to age artificially. You've had the entire repository of the Ancients' knowledge downloaded into your brain. Twice! You have a thing for ''WesternAnimation/TheSimpsons'', fishing, Mary Steenburgen, the color peridot, and you're a terrible ping pong player.\\
[...]\\
'''Jack O'Neill:''' Well, first of all, Joe, I'm ''not'' a terrible ping pong player.
* ItsAllAboutMe: In "2001", Senator Kinsey genuinely believes that O'Neill is willing to sabotage Earth's alliance with the Aschen, which could potentially save the planet from the Goa'uld, all in order to prevent Kinsey from becoming President of the United States.
* ItsAllMyFault: Averted. Daniel's grandfather tries to comfort him over the loss of his parents years ago, telling him it wasn't his fault. Daniel's reply? "Of ''course'' it wasn't my fault!"
* ItsPersonal:
** Daniel Jackson joined SG-1 because his wife, Sha're, and brother-in-law, Skaara, had been taken as Goa'uld hosts. Throughout the series numerous other loved ones are killed or implanted by the Goa'uld.
** Teal'c worked so hard to become First Prime of Apophis because Cronos, ''enemy'' of Apophis, had killed his father and he wanted to be in a position to exact vengeance. He later swore a "Jaffa revenge thing" against Tanith, the Goa'uld that lied to, betrayed and killed Shau'nac, his childhood love interest.
* ItsWhatIDo:
** When O'Neill gets upset at Felger's statement that there are "only" a dozen Jaffa for SG-1 to fight their way through, Felger points out that this is what SG-1 ''does''. The whole team pauses for a few seconds before apparently agreeing and moving on.
** In "Zero Hour", when O'Neill mocks Ba'al as he always does, his new aide asks if it is necessary to actually ''provoke'' him. O'Neill simply turns to him and says, "It's what I do."
[[/folder]]

[[folder:J]]
* JackBauerInterrogationTechnique: Teal'c in "Talion".
-->'''Teal'c:''' You underestimate the satisfaction I will get from your suffering.
* JacobMarleyWarning: Ernest to Daniel in "The Torment of Tantalus".
* JailbaitWait: When Orlin descends for a second time, he is forced by circumstance to take the form of a young boy [[TheNthDoctor instead of the grown man he was in season five]]. He explains that he knew this would cause problems for his relationship with Carter, since he was aware that human societal mores disapproved of a relationship between a grown woman and a child, and hopes that they will be able to resume their relationship in a few years. Carter is unnerved by the entire discussion.
* JurisdictionFriction: Often comes up when SG-1 does an operation on Earth.
** [[AvertedTrope Averted]] in "Touchstone", where Hammond explicitly points out that, since the NID facility officially does not exist, there is no jurisdiction conflict to prevent SG-1 from apprehending its personnel.
** In "Seth", SG-1 believes that the title Goa'uld has been hiding on Earth since the Stargate was buried in ancient Egypt and investigate a cult led by Seth Fargough to see if he is the Goa'uld in hiding. They bump into the Bureau of Alcohol, Tobacco and Firearms which has been monitoring the cult due to its traditionally illegal cult activities (including possession of illegal firearms, rumors of killing dissenting members, etc.) and the ATF refuses to allow the USAF to participate. [[ScrewTheRulesIHaveConnections O'Neill calls the president and has him appoint SG-1 to the operation]].
** In "Wormhole X-Treme!", Carter and Daniel are led to an NID staging ground by their target, who hopes to [[LetsYouAndHimFight delay both organizations]]. Once they have figured out who is who, Carter states that she plans to accompany the NID, but Agent Barrett explains that the NID has been given complete authority in this investigation and will not share it with the USAF.
** In "Uninvited", the Air Force takes over an investigation from the local sheriff when they determine that the bear that has been killing local hunters is actually a dangerous creature [[NiceJobBreakingItHero that they inadvertantly created.]] They stick with the "bear" story, of which the sheriff is understandably skeptic since they explain that it is a matter of national security [[spoiler:but he never gets a chance to dig deeper since the creature kills him at the end of the scene]].
* JustFriends: Jack and Sam maintain a façade of simple friendship, [[AvertedTrope but they have both admitted their feelings and decided not to act them due to their responsibilities and regulations]].
* JustifiedTitle: The two-hundredth episode of the series was titled simply "200", with Mitchell explaining in the episode that this is his two-hundredth trip through the Stargate. However, [[LampshadeHanging the other characters realize that he has not been with the program long enough to have been on anywhere near two hundred missions]], and he explains that he means it has been two hundred times that he has travelled through a wormhole, including coming back to Earth from missions, going back and forth from one alien planet to another, etc.
* JustifiedTrope: The show actually bothers to explain why almost every planet with a gate is suspiciously Earth-like [[PlanetOfHats with a single culture]], why the [[BigBad Goa'uld]] are so [[LargeHam cartoonishly over-the-top]] and [[EvilOverlordList take so long to wise up]], why the [[NeglectfulPrecursors precursors were so neglectful]], and more. And if it does not get justified, it probably gets [[LampshadeHanging lampshaded at some point]]. Including [[PlayingWithATrope Lampshade Hanging itself]]...
[[/folder]]

[[folder:K]]
* KangarooCourt: "Cor-ai" features Teal'c being put [[TrialOfTheMysticalJury put on trial]] for killing a man while he was still serving Apophis. The twist was that his prosecutor was the son of the man he killed, and was also the judge and jury. Jack greatly complains about this, only for Daniel to say that this has historical precedent. Which just pisses Jack off.
* KickedUpstairs: After General Landry settled in at the SGC he realized that most of the meetings he had to go to were basically pointless and orders Sergeant Walter "Chevron Guy" Harriman to go in his stead. When Walter protests, Landry threatens to promote him if that is what it takes.
* KilledOffForReal: [[spoiler:Major Kawalsky, Sha're, Martouf, Apophis (eventually), Narim (and the rest of the Tollan), Janet Frasier, Jacob Carter, Colonel Pendergast and the ''Prometheus'', Col. Chekov and the ''Korolev'', and ''the entire Asgard race''. Abydos is destroyed and everyone on it is killed, but they are AscendedToAHigherPlaneOfExistence.]]
* KilledToUpholdTheMasquerade: Maybe. A reporter with information on the Stargate Program is killed in a car accident mere seconds after O'Neill fails to convince him not to run the story, but O'Neill claims (and is assured by General Hammond) that the Air Force had nothing to do with it. (The NID, on the other hand...) The truth is never revealed to the audience one way or another.
* KineticWeaponsAreJustBetter: Played straight; most characters use [=SMGs=] or handguns for the whole series and even Teal'c trades in his staff weapon for a P90 (or [[GunsAkimbo two]]) in the last three seasons.
* KingArthur: Seasons nine and ten delve deeply into Arthurian legend, with the revelation that {{Merlin}} was an Ascended Ancient who retook human form in order to build a weapon to fight the Ori. Though Arthur himself never appears, SG-1 does visit Camelot and follows in his footsteps to look for the ''sangraal'', the HolyGrail, which they believe to be the weapon that Merlin built.
* TheKirk: More often than not, Samantha or Daniel.
* KissingUnderTheInfluence: In the first season episode "The Broca Divide", ''before'' the heavy ShipTease began between O'Neill and Carter, Carter attempted to force herself on O'Neill when she began to regress into a primitive being. [[PlayedForDrama It was not a funny scene]].
* KlingonPromotion:
** The Jaffa rite of "''joma secu''", where a Jaffa commander is challenged to a duel to the death for his position. Played straight in "The Warrior" (Teal'c versus K'tano[[spoiler:/Imhotep]]; Teal'c wins) and subverted in "Birthright" (Ishta versus Neith; Ishta wins but spares Neith when she learns the tretonin didn't work on Mala and she died).
** In "Bounty", SG-1 points out that Netan's position in the Lucian Alliance is extremely tenuous and that if somebody managed to kill him they could probably take over the entire organization.
* {{Knighting}}: In "Theads", Teal'c and Bra'tac are dubbed "blood-kin to all Jaffa" in recognition of their work in the overthrow of the Goa'uld, tapped once on each shoulder by a staff weapon.
* KnightsTemplar: Plenty, but particularly the rogue NID, which became the Trust.
[[/folder]]

[[folder:L]]
* LamePunReaction:
** The System Lord Yu's name is frequently punned by the humans due to its similarity to the English word "you". When Dr. Elizabeth Weir, who was only learning of Yu for the first time, began to make her own pun, Daniel explained to her that every possible variation had been done to death, and it was no longer funny.
** When the team first figures out that Ba'al has been cloning himself in "Insiders", they end up having to capture the whole lot and bring them back to the SGC. At one point Cam Mitchell drops this one:
--->'''Mitchell:''' (''to [=CMSgt.=] Harriman'') Chief, we got a full count. Two strikes, three Ba'als.\\
'''Harriman:''' (''chuckles'') Oh. That's clever, sir.\\
'''Carter:''' (''eye roll'') He was thinking that one up the whole way home.\\
'''Mitchell:''' Yeah, the whole three seconds.
* LampshadeHanging: Frequently, often pairing up with GenreSavvy (see above), and forms the basis for much of the series' humour, particularly when Colonel Mitchell (Ben Browder) joins the cast. The episode "200" lampshades tons of tropes from sci-fi and movies in general to the show itself, including the act of Lampshading!
* LargeHam: The Goa'uld have a habit of this [[JustifiedTrope for various reasons]].
** Rodney [=McKay=] lampshades it in "Redemption, Part 2" after Anubis tells the SGC they're all going to die at the end of Part 1:
--->'''[=McKay=]:''' Hello, Anubis, this is your agent. You're playing it way over the top; could you please tone it down?
** O'Neill also mocks the Goa'uld hamminess repeatedly. Again, from "Redemption, Part 2":
--->'''Anubis:''' [ResistanceIsFutile speech]\\
'''O'Neill:''' Come on. Who talks like that?
** President Henry Hayes has shades of this in his conversation with Anubis In "Lost City", complete with LampshadeHanging.
--->'''Henry Hayes:''' Never going to happen. (''Anubis' hologram vanishes, Hayes turns to his onlookers'') Too much?
* LaserGuidedAmnesia: "Fire and Water"; "Beneath the Surface"; "Fallen"; "Revisions"; "Collateral Damage"; "Memento Mori"
* LawOfInverseFertility: In the alternate timeline of "2010", Carter and her husband Ambassador Joseph Faxon are trying very hard to have a child, but so far are unsuccessful [[spoiler:thanks to the Aschen]].
* LaymansTerms: Frequent. ''Especially'' whenever Daniel or Sam try to explain something to O'Neill. Whenever [[InvertedTrope O'Neill uses a technical term himself]] it is usually cause for a double take from the other characters.
* LeaningOnTheFourthWall: The episodes "Wormhole X-Treme!" and "200". Also, this gem of an O'Neill quote:
-->'''Local:''' (''about Teal'c'') He is Jaffa!\\
'''O'Neill:''' No, but he plays one on TV.
* LearntEnglishFromWatchingTelevision: Orlin learned to speak English, and how to dress, by watching TV in Carter's house overnight.
* LeaveHimToMe: At the conclusion of "Talion", Teal'c has been shot at least twice by a staff weapon and is brought before Arkad, who tosses him a wooden staff and orders his men to leave them alone. He then fights Teal'c one-on-one, explaining how [[WorthyOpponent he has always admired the fierce warrior Teal'c, and that he wants to kill him himself]]. [[spoiler:Teal'c, though viciously beaten, kills Arkad.]]
* LeftItIn: In the "documentary" made about ''Wormhole X-Treme!'' at the end of "200", Martin Lloyd stops his interview to take a phone call, during which he is quite profane, and then goes back to talking about how much of a family the crew is after checking to make sure that they had not recorded his previous comments.
* LensmanArmsRace: The SGC goes from a platoon-sized group of special forces going through a star gate they barely know how to operate, to a small fleet of interstellar star ships, in about eight years.
* LetsSplitUpGang: Daniel lampshades it when the Russian Major he is trapped in a Goa'uld ziggurat with leaves to explore the hallways and tells Daniel to wait there; commenting that both of them will be alone in a dark and dangerous maze.
* LetUsNeverSpeakOfThisAgain: The season one episode "Hathor" was heavily disliked by both fans ''and'' the producers, and in following episodes the characters mention that they have agreed to never talk about it again. True to that, [[CanonDiscontinuity the specific events of the episode are never revisited]], with characters only talking about the "Hathor incident" without saying what actually happened, and the details of how Goa'uld queens produce offspring being {{retcon}}ned to asexual. Even Hathor's reappearance in "Out of Mind" and "Into the Fire" doesn't go into many details, only that the team, particularly Daniel and Jack, have developed an intense loathing of her.
* LieDetector:
** The Toka'ra have a lie detector which works via mind reading. Instead of actually reading if a character is being truthful or lying, it reads their conscious and unconscious thoughts and compares them, to see if their recollections match what they are saying. It is used to detect a ''zatarc'', a person that the Goa'uld have brainwashed into an assassin and then covered up their brainwashing with false memories.
** Vala is given a polygraph when she is being reviewed for suitability to formally join the SGC. Its use is in line with most flawed depictions of the polygraph, indicating that Vala is lying when she tries to compliment the doctor [[DiggingYourselfDeeper and noting each successive lie when she tries to cover herself]].
* LikeAnOldMarriedCouple:
** Most of the interaction between Vala and Daniel.
** In "Past and Present", an entire planet has suffered chemically-induced amnesia. Two of the inhabitants, Orner and Mayris, constantly argue LikeAnOldMarriedCouple. [[spoiler:Turns out they actually ''were'' married before they lost their memories.]]
* LikeASonToMe: In "Talion", Bra'tac explains to Teal'c that he is like a son to him, and that he is [[SoProudOfYou so proud of him]].
* LikeRealityUnlessNoted: Unless the show outright says so, what's happening outside of the Stargate program is the year that particular season was produced.
* LiteralMetaphor: How did General Landry manage to have BigEater Goa'uld Nerus leave the SGC with a subspace tracker? It was a piece of cake....
* LivingForeverIsAwesome: Harlan, a human [[BrainUploading whose brain was uploaded into a robot body]] and refers to this process as a "gift". He is shocked that SG-1 does not share his opinion, though he does admit that others of his kind also had trouble accepting their state of existence.
* LockingMacGyverInTheStoreCupboard: In "Ripple Effect", when the Alternate SG-1 lock them in the brig of the ''Prometheus'', Sam is able to break out almost immediately by rerouting a power cable running through the wall. When asked how she knows it will work, her response:
-->'''Sam:''' Because I helped build it.
* LongevityTreatment: Several examples, all with severe side effects:
** The sarcophagus can extend the life of a human without a [[PuppeteerParasite Goa'uld]] for 700 years or so, hosts for millennia. Unfortunately it makes the user megalomaniacal.
** In the episode ''2010'' the Aschen give Earth a life-extension drug that serves to explain why SG-1 hadn't aged at all in ten years. It also turned out to cause sterility, as part of an Aschen plot to depopulate Earth so they could turn it into an agricultural colony, necessitating TimeTravel to prevent the Earth-Aschen alliance.
* LongGame:
** The Aschen as a whole are a very patient race, and conquer other planets over the course of centuries. Their standard operating procedure seems to be forming an alliance with the current government and granting them superior technology in order to gain their trust, but slowly reducing their population by [[SterilityPlague inducing wide-spread infertility through their medical treatments.]] After several centuries the planets inhabitants will be too few to prevent the Aschen from assuming complete control.
** This is also how the Tok'ra planned their fighting of the Goa'uld, until SG-1 started wiping out system lords.
* LongRunners: ''Stargate SG-1'' ran for ten seasons and a total of 214 episodes, with two additional DVD movies, and was followed by [[Series/StargateAtlantis two]] [[Series/StargateUniverse spinoffs]]. ''Series/{{Smallville}}'' rivals it as an North American series for equivalent seasons and episodes, while only ''Series/DoctorWho'' tops it worldwide.
* LookBothWays: The female bounty hunter after Daniel Jackson in "Bounty" is killed by a bus as she stalks across a street. [[JustifiedTrope She probably should have researched the planet and learned our traffic patterns]].
* LoopholeAbuse:
** Daniel gets away with helping the Tollan escape because, as a civilian, he cannot be court martialled, and he could not be tried in civilian court without revealing the Stargate Program.
** In "Pretense", one of the Nox helps the Tollan defend themselves by hiding one of their planetary defense turrets so it is not destroyed by the Goa'uld. When Carter calls her out on doing this despite her people's dedicated pacifism, she remarks that she only ''hid'' the weapon -- she did not fire it. Carter remarks that that is a pretty fine line she did not cross.
** In "Lockdown", O'Neill is complaining about his recent promotion to general, particularly about the pressure he is under to appoint a new member to SG-1. When he explains that he wants to keep it like it is, as a three-person team, Carter points out that there is no rule that says SG-teams ''have'' to have four members, and O'Neill latches on to that rationale as a way to avoid making the decision.
** Subverted in "Fair Game". After hearing the System Lords demand for the Earth's Stargate, Jack clearly seems to be thinking that they can swindle them, only for Yu to then clarify that they meant ''both'' of them!
* LostSuperweapon: When Earth is under the threat of a massive alien invasion and if the usual tricks and weapons do not work, there is the ancient outpost in [[MysteriousAntarctica Antarctica]], whose chair can control and launch thousands of powerful drones, only requiring a humongous amount of power. [[SuperweaponSurprise Surprise!]]
* LostTechnology: Lampshaded by Colonel O'Neill in a Season 6 episode where the HumanAliens have no artifacts from the Goa'uld.
-->'''O'Neill:''' That's weird. The Goa'uld are damn litter bugs, they leave all kinds of crap lying around.
* [[LoveAtFirstSight Love at First Mind-Meld]]: Orlin falls in love with Carter the very instant he meets her, but he tries to justify it by explaining that Ascended beings can join their essences to another person and understand them on a fundamental level right away. Carter is skeptical and, even though she warms up to him eventually, never does fall in love with him in return.
* LowCultureHighTech:
** The slave races to the Goa'uld and Ori.
** Earth, after the SGC begins truly piling up the alien tech.
* LowerDeckEpisode
* LuddWasRight
* LukeIAmYourFather: Wonderfully played with and torn to shreds during the 200th episode. For a moment, you almost believe...!
[[/folder]]

----