The pilot had a (extremely brief) moment of confusion with regards to Carter. When General Hammond mentioned that their foremost expert on the stargate, Sam Carter, would be arriving soon, O'Neill asked where he was transferring from, only for Carter to walk in at that point and say that she is transferring from the Pentagon.
Val Mal Doran was introduced in "Prometheus Unbound" in the armor of a Kull Warrior with an artificially-deepened voice. She had already taken the Prometheus and flirted with Daniel Jackson before the helmet was removed to reveal that she was a woman. Which Daniel found extremely disturbing when he thought she was an actual Kull Warrior.
Sanity Has Advantages: The Goa'uld as a whole. Sure, they have an enormous technological advantage thanks to their genetic memory, but said memories as well as abuse of the sarcophagi mean they are all megalomaniacal cliché villains. Furthermore, most of them believe in their own propaganda about being gods, and act with the expected supreme arrogance. The System Lords spend most of their time and ressources fighting each other rather than dealing with their common enemies, which both Tok'ra and Tau'ri gladly take advantage of. They also waste their soldiers by slaying them for the slightest failure or insisting they always fight to the death, even against disastrous odds, rather than withdraw to win another day. The Goa'uld were the dominant species of the Milky Way till season 8, but they would have been infinitely more powerful if only they had co-operated from the start, rather than being forced to by Anubis or the Replicators. Notably, the few System Lords that don't buy fully the godlike nonsense (like Ba'al, or Yu before he went senile) are portrayed as much smarter and dangerous than their brethren.
Saving The World With Art: In "Learning Curve", the team discovers a planet where certain children soak up knowledge and then have it all removed from their minds in order to distribute to the entire population, after which they are reduced to an infant-like state. Since the society has lost the ability to teach through traditional means, these children are put into care homes for the remainder of their lives. Appalled by this practice, but unable to do anything about it, O'Neill makes one girl spend her last day "acting like a kid" by playing games with other children and learning how to paint before giving up her knowledge. Next time SG-1 visits, it is completely transformed with children playing games and adults drawing pictures. The previously neglected children are now being cared for and reeducated, allowing them to have a new life where previously they had none.
Saw "Star Wars" Twenty-Seven Times: Teal'c and O'Neill drop by Carter's place with pizza and Star Wars, which O'Neill assumes must be be an okay movie because T's watched it nine times. Carter, however, thinks O'Neill is the weird one.
After being indoctrinated by the Goa'uld over the millennia, the Jaffa look like this, especially the Free Jaffa Nation. Teal'c frequently shows irritation that they're stuck in the "old ways" even after they gained their freedom in Season 8.
The Bedrosians from "New Ground". Unlike the Optricans, their rivals from another continent, they refuse to believe their people were once slaves brought through a gateway by an alien being, posing as a god. It just had to be this world the SGC happened to cold-dial, just as one of their scientists uncovered the Stargate....
Sci-Fi Name Buzzwords: When Vala pitches a story idea based onThe Wizard of Oz, she tries to disguise it by renaming the primary events characters with Stargate-themed titles. The house caught in a tornado becomes a cargo ship that crashes on a planet, the Wicked Witch of the East is the local ruling Goa'uld, Glinda the Good Witch is "a lovely, fair-haired Tok'ra" and Oz is a wise Ascended being. Martin Lloyd sees right through the whole thing.
Sci-Fi Writers Have No Sense of Scale: Averted. Traveling between different stellar systems, even at faster than light speeds, takes months or years (the fastest Goa'uld ship encountered can travel at 32,000 times the speed of light, which would take three years to cross the diameter of the Milky Way Galaxy), which is why the Stargate Network is still vital to the Goa'uld economy and military complex. The concept of conquering a planet requires millions of soldiers and defending a planet, even with technologically-advanced weaponry, requires numerous weapons placed all around the planet, not just at vital areas. Multiple characters point out the flawed thinking of other people when they fall into the traditional pitfalls of discounting the sheer size of the universe.
Screw the Rules, I Have Connections!: After they have saved the world numerous times SG-1 is able to place direct calls to the President of the United States when they need a favor.
In the pilot episode, O'Neil(l) admits, in his roundabout way, that his report on the first trip was not completely accurate because a) genocide against the Abydonian slaves would not be right and b) technically, they did nuke Ra, who was the actual threat.
In the first season episode "Enigma", Daniel Jackson goes against orders to help the Tollan get to their stargateless new world. Not being a member of the formal command structure and a vital asset, he gets away with it.
In the first season finale "Within the Serpent's Grasp", the whole of SG-1 disobeys orders to launch a first strike against Apophis and his assault upon the planet after the Obstructive and Corrupt BureaucratSenator Robert Kinsey shuts down Stargate Command.
In the Ori arc, three ascended Ancients are shown to do this to help humanity. Merlin de-ascended to develop a weapon capable of killing the Ori, Orlin did the same to help develop a cure to the Ori plague, and Morgan Le Fay just flat-out broke the rules by intervening while still ascended (which she could get away with because she was no longer in Ancient territory).
Done most often by O'Neill, to the Asgard, Tollan, and the Tok'ra. The Asgard must have found it funny, and actually listened to him. The Tollan were eventually wiped out, after demonstrating the shallowness of their principles.
Daniel tries to do it to the Ancients, but they ignore him.
Secret Government Warehouse: In "Point of View", the alternate Carter and Kawalsky arrive in our reality in one. It looks like it could've been filmed in the props department.
Seinfeldian Conversation: When Mitchell, Daniel and SG-22 have managed to capture a Prior, Mitchell spends a lengthy period trying to get the Prior to discuss the recipes of the Ori home galaxy. He, in turn, explains how to make a delicious omelette, and is disappointed when the Prior will not even give a pie crust.
Season eight's "Citizen Joe" features a man who is unwittingly receiving visions of events that occur throughout the series and tries to publish short stories based on them. The writers took this opportunity to poke fun at some of their more disappointing episodes and plotlines, along with persistent issues among fans of the show.
Both the 100th and 200th episodes celebrate by spending the episodes poking fun at their own show general Sci-Fi clichés.
Self-Healing Phlebotinum: Human-form Replicators can regenerate from damage dealt by virtually any weapon except the anti-Replicator gun. Regular Replicators are also sometimes seen reforming after being blown apart, though there's apparently a critical mass of intact blocks that have to be within a certain distance of each other for this to work.
Self-Insert Fic: "Wormhole X-Treme!" reveals that when Martin originally wrote his treatment for the Show Within a Show, it had a fifth character based on himself, which he describes as a handsome alien marooned on Earth when his crew betrayed him. The executives took that part out.
Self-Parody: The self-referential episodes "Wormhole X-Treme!" and "200" revolve around the making of a Show Within a Show based on the exploits of SG-1, with many jokes and insults aimed at sci-fi clichés and past stories of the SGC.
Semper Fi: SG-3 is a dedicated combat support group composed of US Marines. It was originally commanded by Colonel Makepeace, former Trope Namer of Hero of Another Story, and then led by Colonel Reynolds in the later seasons. SG-5 and SG-18 are also drawn from the Marines.
Send in the Clones: Ba'al's clones (to great comedic effect) and, to a much lesser extent, the Asgard.
In "Prodigy", when a group of scientists disparage O'Neill's experience and right to be in command, Teal'c walks up and "strongly advises" that the scientists listen to O'Neill. Afterwards, O'Neill calls Teal'c "Rocco".
Arkad, a Jaffa hoping to lead others to follow the Ori, attempts to bully Earth into not opposing his plans by informing them of a plan to attack the planet that he can help them thwart. SG-1 and General Landry are well aware of exactly what he is doing, and do not even let him finish his speech before ridiculing his actions and likening him to a criminal thug.
Shell-Shocked Veteran: Vernon in "Sight Unseen". Due to his experiences during the Gulf War, he comes to believe that the creatures being seen in Colorado Springs are due to government experimentation, recognising that the cover story about a toxic spill was clearly bogus. O'Neill eventually cops to it and admits Vernon was Right for the Wrong Reasons.
Ship Tease: O'Neill and Carter being the biggest case. You know you are being teased when every non-military alternate version of Carter is married to the O'Neill of her reality.
Shoot the Shaggy Dog: "Ethon". SG-1 successfully mediates a truce between the two nations, only for them to destroy each other immediately after they leave.
Shot to the Heart: Happens in the episode "Avatar", in which Teal'c gets trapped in a virtual reality training program that shocks him every time he dies to increase the realism. The doctor monitoring him has to administer an adrenaline shot when his heart stops after dying for the umpteenth time.
Show Within a Show: Wormhole X-Treme!, used twice to great comedic effect, including the celebrated 200th episode. Its original run was cancelled after airing three episodes, but it sold so well on DVD that the studio decided to give it a movie adaptation. The production of the movie was then frought with issues and the studio decided to cancel production, but decided to relaunch the series again and it aired for ten years, with the movie greenlighted (again) after the two-hundredth episode of the series.
Invoked as Gallows Humour, when they though the Gate might have caused Daniel to have developed full-blown schizophrenia:
Jack: Why can't we just put a little sign on the end of the ramp, "Warning: Gate travel might be hazardous to your health!" I could live with that?!
Also when testing the anti-prior device for the first time:
Daniel: That warm, fuzzy feeling you're experiencing may be the effects of a device that is inhibiting your ability to concentrate and focus your powers. Mitchell: Symptoms may include dizziness, irritability... Daniel: Nausea. Mitchell: Mild nausea, and a condition known as hot dog fingers.
You won't find the Ori symbol just on the Book of Origins' cover. In their galaxy, it is everywhere — on the Prior's clothes, the crusaders' weapons, the light fixtures, the fire pits they execute nonbelievers in, the power sources in their ships... even the ships themselves follow the pattern.
To a lesser degree, the System Lords invoke this by adorning all their Jaffa with their own respective sigil.
Signature Item Clue: In one episode, SG-1 goes to a planet they've never been to before and find a pack of Russian cigarettes. When they get back they have a little chat with the Russians about what they were doing there and what they found.
Sincerity Mode: When discussing the Goa'uld Nerus, who has contacted the SGC in the hopes of working together against the Ori, General Landry says that he had nice things to say about SG-1. The scene then cuts to Daniel Jackson reading Nerus' communication and he remarks with surprise that Nerus really did have some very nice things to say about SG-1.
The Canon on the medieval planet in "Demons" made use of creative interpretations of The Bible, the fear engendered by the Goa'uld System Lord Sokar's raids for hosts, and a lightning-summoning ring in order to maintain control over his village. When SG-1 arrived, he accused Teal'c of consorting with demons.
All the Priors of the Ori are downright scary.
Averted with Jaffa Priests and Priestesses, who despite being forced to worship the Goa'uld for most of the series, tend to be some of the most unambiguously heroic and level-headed of all Jaffa.
Single-Biome Planet: Deconstructed, as the characters often decree the nature an entire planet based only on a brief exploration of the area surrounding the gate. One member concluded that she was on an "ice planet" when she found herself in Antarctica by mistake, and many characters point out that a day of exploration does not come close to discovering what might be just out of visual range.
Sliding Scale of Idealism vs. Cynicism: Contrasts Daniel Jackson, who cares about making friends and allies, to the NID, who care about getting technology to defend Earth at any cost, and Jack O'Neill, who is somewhere in the middle, mostly on the side of pragmatism. An example of the show running on different points of the scale is "Scorched Earth", where Daniel finds a way to save both civilizations vying for control of the planet's ecosystem despite Jack's plan to blow one of them up with a naqadah bomb, and "Entity", where Daniel and Sam's idealism leads to the latter being possessed by a vengeful (our probes accidentally caused damage to them) computer entity, even then Daniel insists Sam trying to make contact with the creature was not the wrong move. The entity only releases its hold on her when Jack threatens to send more probes. Jack basically has to tell Daniel to shut up, and let him do it his way.
Smart People Play Chess: Samantha Carter plays chess with Cassandra every Saturday. Cassandra mentions O'Neill, and states that he's not as dumb as he pretends to be. The example she gives of his Obfuscating Stupidity is that he insists on calling the knight pieces "horses".
So Beautiful, It's a Curse: At least one minor character uses this trope almost verbatim, with the justification that Goa'uld always want attractive hosts, so being too pretty is more than just a social problem. Since said character was captured as a girl and trapped as a Goa'uld host for god-only-knows how long until her symbiote was killed, it really was A Fate Worse Than Death.
Society-on-Edge Episode: This show has multiple episodes involving this. One example is season eight's "Full Alert," where the Goa'uld attempt to trigger World War III between Russia and the United States.
Some Kind Of Forcefield: Several varieties of forcefields appear in the series, with various visual effects revealing their presence. Most of them are indeed invisible unless touched, but the results of a contact are quite variable.
In "Upgrades", the Goa'uld forcefields inside a ship in construction glow blue and look somewhat like frost on windows when touched — or when going through at Super Speed thanks to the Atoniek armbands.
In "Deadman Switch", Daniel Jackson walks nose-first into a red-glowing forcefield, put in place by Aris Boch to capture SG-1.
Daniel: *klonk* OW! Found something...
In "Windows of Opportunity", a forcefield surrounding Malakai and the Ancient control device doesn't just glow when hit: a mere contact propels Teal'c backwards and knocks him out. When the team tests the field again by throwing a stone at it, it shoots back with the speed of a bullet.
In "The Other Guys", SG-1 is imprisoned in a forcefield that glows bright white on contact — as well as giving a serious shock when touched, if O'Neill's reaction is anything to go by.
In "The Ties That Bind", the power coil-slash-religious device is protected from thieves by a small forcefield, invisible until Daniel touches it, stinging his fingers. DVD commentary reveals it was a Throw It In by Michael Shanks; although not planned in the script, the special effect was added afterward.invoked
Something Only They Would Say: In "Crystal Skull", O'Neill starts to believe that he really is talking to Daniel when Nicholas Ballard responds to one of his flippant remarks with "Jack, don't be an ass."
Sorting Algorithm of Evil: The series started with Apophis. When they finally got rid of him, even stronger Goa'uld showed up. But that's okay, the team got good at dispatching Goa'uld. So Anubis shows up, with the full knowledge of the godlike beings who had created the Stargates. But they took care of him — though it was a close one. For almost a whole month there is peace. Then the godlike Ori turn up.
This progression is grounded in the plot by the Tok'ra. They say that every time the Tau'ri defeat a System Lord, an even worse one inevitably takes advantage of the power vacuum. By killing Ra, and others, SG-1 kept disrupting the Goa'uld balance of power, allowing more aggressive Goa'uld to sweep up now-leaderless forces and rise in threat level. They didn't cause Anubis, but probably sped up his timetable. They did make the Replicators more dangerous, by giving the nanotech precursor of the Replicators to the Asgard, from whom it was then captured. In a self-application of Stop Helping Me!, the Ori only found out about the Milky Way galaxy when Daniel Jackson and Vala accidentally warped over to their home galaxy and caused a scene. An unfortunate coincidence, perhaps, but still their doing.
In "Heroes", O'Neill goes on a tirade against Senator Kinsey, most of which is drowned out by the alarm announcing an incoming wormhole. Judging by mouth movements, situation, character, Kinsey's expression, and the timing of the intercom's interruptions... the rest was very rude.
O'Neill: You smarmy, self-righteous, opportunistic ass— Intercom: (with siren) Unscheduled off-world activation. O'Neill: You're nothing but a l— Intercom: Repeat, unscheduled off-world activation.
In another episode, Sam Carter refuses to ask out another female staffer on Jonas Quinn's behalf, telling him, "You are such a chickensh—" before getting cut off by an alarm.
The Asgard and the Goa'uld prior to the series, whose relations are governed by the Protected Planets Treaty. This treaty forbids Goa'uld invasion of certain worlds, and requires that the Goa'uld as a whole stop any rogue Goa'uld from doing so, but simultaneously acknowledges that humans exist to be hosts for the Goa'uld, and thusly are to have limited technology so as to never pose a threat to the System Lords. When Jack O'Neill questions why the Asgard stand for such a thing, and why they even allowed the Goa'uld to gain such power in the first place, Thor explains that the treaty is actually a complete bluff. The Asgard are so occupied fighting the war with the Replicators that they do not have the resources to actively combat the Goa'uld, forcing them to accept this "peace".
Langara prior to "Homecoming" was engaged in a cold war between the three dominant superpowers. When two of those superpowers ally in "Shadow Play", the third, Kelowna, launches a preemptive strike with a naquadria bomb. This terrifies all combatants enough to prevent further hostilities until Anubis arrives and renders their internal conflicts moot.
In "Icon", the cold war on Tegalus between the Rand Protectorate and Caledonian Federation is disrupted by SG-1's arrival, which allows a religious extremist faction to rise up in Rand, eventually overthrowing the government and starting a war which reduces most of the continent to rubble. The SGC helps the Rand loyalists regain control, but the international tensions remain into season nine's "Ethon", when the Ori give the Rands a Kill Sat.
Notable in that the villains have space fighters from the very start, but the good guys have to develop theirs slowly over several seasons. As with most of Goa'uld technology, their Death Gliders are more impressive than practical.
The F-302, the USAF finalized space fighter design, takes many of the Glider's systems and adds all the trappings of a modern jet fighter (missiles, ejector seat, autopilot, etc.). The prototype, the X-302, also had a naquadriah-powered hyperspace generator, but the instability in the naquadriah meant that it could not function as a means of transport and was removed from the standard production model.
The Ori crusaders have space fighters too, which easily curbstomp Death Gliders.
Space Is an Ocean: Partially averted, with space travel being in the hands of the Air Force. Most of the trappings of this trope are there, but they specifically avoid naval terminology; they use missiles instead of torpedoes, almost nobody says "port" or "starboard", the ships are flown by a pilot instead of a helmsman, etc. At the same time, given the size and purpose of the larger craft, it is apparently acceptable to refer to BC-303s and BC-304s (which do kinda look like flying aircraft carriers) as Prometheus-class and Daedalus-class ships, respectively.
Space Mines: "The Serpent's Venom" takes place in a space minefield where the mines all lock onto any sign of weapons, which is used by the Goa'uld as a neutral meeting place. SG-1 has to reprogram a mine to attack one of the Goa'uld ships at the meeting in order to instigate a conflict.
A slingshot maneuver around Jupiter is attempted by O'Neill and Teal'c to get the X-301 turned around in "Tangent", but the attempt fails as the rockets they are using, the pair of Sidewinder missiles the 301 is equipped with, lack thrust.
In "The Pegasus Project", the Odyssey successfully pulls one around a black hole, after goading a Wraith Hiveship to follow them. They make it, while the Hiveship has no such luck due to the Odyssey using the fact that the black hole is disrupting their systems to beam a nuke inside the ship.
Stalking Is Love: Averted. Orlin claims that he loves Carter, but she explicitly points out that he is stalking her, and what they have is not a "relationship". She does warm up to him eventually, and even grows to like him, but she never falls in love with him in return.
Standard Sci-Fi Army: Typical for television, the military forces are limited to infantry. Considering the Stargate limits how much can go through, it's justified.
Sterility Plague: In the Bad Future portrayed in "2010", the Aschen plan to surreptitiously conquer Earth involves one of these, distributed under cover of advanced medical tech. As shown in the later episode "2001", this is their modus operandi.
Strange Minds Think Alike: General Landry has a habit of quoting famous historical generals, and he is in turn occasionally quoted by Colonel Mitchell. In "Counterstrike", Mitchell repeats a quote Landry has given, explaining it came from Sun Tzu, but he then amended that Landry might have actually been repeating Dr. Phil that time. In the next scene, when Landy provides a different quote to Bra'tac, who praises the wisdom of the warrior who provided it, Landry said that that time he was quoting Dr. Phil.
Daniel: (in the grip of a translation eureka moment) Sphere. Planet. Label. Name. Jack: Following. You. Still. Not.
Stupid Evil: The Goa'uld; in "In the Line of Duty" Teal'c explains that he has seen certain victory turn to defeat simply because the Goa'uld cannot rein in their gloating or pointless sadism.
Stupid Sacrifice: Averted by the ever Genre Savvy O'Neill. After successfully destroying the shield system on an invading Goa'uld mothership, they ponder their next move. The following dialogue occurs:
O'Neill: Now what? Bra'tac: Now, we die. O'Neill: Well, that's a bad plan. Where's the glider bay?
The Nox, introduced in the self-titled episode "The Nox", possess the ability to raise the dead, teleport from point to point, activate a Stargate with a wave of the arms (no DHD needed) and become intangible/invisible at will. They accomplish these feats with woodland rituals, symbolic gestures and a philosphy which emphasize nature and pacifism. The end of their introductory episode reveals that they do have a technological city, but their skills and abilities do not visibly derive from it.
The unnamed aliens masquerading as the divine spirits of a group of Salish-descended people have the ability to change their shape and image, communicate telepathically and make people appear/disappear. This is accomplished with only a wave of their arms and is effective across interstellar distances.
The episode "Threads" has Carter's cell phone ring in the SGC briefing room. The briefing room is 28 floors underground inside a mountain. (See also Rule of Funny, given that she thought she had it turned off.)
In "200", Martin Lloyd complains that his cell reception is terrible in the SGC briefing room. As above, the fact that he gets any signal at all is a miracle. Again, Rule of Funny may be in play given the mostly parodic nature of the episode.
Superpowers For A Day: The human members of SG-1 gain extreme strength, speed and senses while wearing the Atoniek armbands. They have the ability to kick through solid concrete, move faster than the human eye and see in almost complete darkness. They can even see the modulations of Goa'uld forcefields, and run so fast that they can go through them. Unfortunately, their judgement is compromised at the same time.
Suspiciously Specific Denial: When the pilot was Re Cut into a DTV movie, Carter's infamous "reproductive organs" line was removed in order to give the character more natural dialogue. Unfortunately, O'Neill's response is kept intact, so in the new film, instead of refuting an accusation that he is sexist, he instead brings up her gender apropos of absolutely nothing.
Goa'uld and Tok'ra straddle the line between mutualism and parasitism. The host gains an extended lifespan, Healing Factor, and boosted strength, while the symbiote gains a body with hands and a voice. On the other side, the symbiote can also take over the host body completely; the difference between Goa'uld and Tok'ra is mainly the conscious choice whether or not to do this. The Tok'ra also only take volunteer hosts.
The fact that the Tok'ra sometimes break their own rules in this regard muddies the waters. In their first episode, "In the Line of Duty", the Tok'ra Jolinar jumps hosts to Carter and takes her over (but she was desperate). In the second case, O'Neill was given a symbiote to save him from the Ancient plague in "Frozen". As a byproduct of the blending, the Tok'ra gained Jack's code of ethics, including No One Gets Left Behind, so it took over his body and went to a Ba'al-controlled planet to extract someone who had helped him on a previous mission.
Anubis is a full-on parasite. Having been kicked partway back down to the lower planes by the Ancients to punish Oma Desala for helping him Ascend to a Higher Plane of Existence, he exists as an Energy Being that needs either a force-field suit (through "Lost City") or a host (season 8) in order to interact with our world. The host has no control over their body and treats Anubis like an infection, breaking out into lesions and eventually suffering immune system failure.
Sympathetic Murder Backstory: In "Collateral Damage", Cam recalls a mission in the Middle East during which he bombed what he believed to be enemy targets only to learn that they were a convoy of refugees.
Take a Third Option: In The Teaser of "Proving Ground", this is actually the correct solution. The end of the training scenario has Sam holding Daniel at gunpoint, each claiming the other is a Goa'uld. In Lt. Hailey's words, the solution is to zat them both and sort it out later.
In "Orpheus", Carter discusses seeing the movie Signs and is incredulous that the alien's weakness was water. When Daniel asked her why she even watches science-fiction if she is just going to tear it apart, she mentions that she wants to see if they are getting it even close to right.
Taking the Bullet: In the second episode of season 7, Jonas Quinn takes a staff weapon blast aimed at Daniel Jackson, expiating for having caused Jackson's death (and ascension) at the end of season 5. He survives, though.
The Alternate Samantha Carter of "There But for the Grace of God" lured in several Jaffa with the offer of valuable information for Apophis, then pulled out a grenade to take them out along with her.
During the Battle of Antarctica in "Lost City", Hammond orders the Prometheus onto a collision course with Anubis' flagship, saying "We go, they go." Subverted in that the weapons of the Ancient outpost get there first, and Hammond is only too happy to break off.
Talking to Themself: Since the Tok'ra share their hosts' bodies symbiotically rather than taking it over, this is known to happen. Before Selmak takes Jacob Carter as a host in "The Tok'ra, Part 2", Samantha remarks that once blended Jacob could spend hours cracking himself up. "Seth" includes Selmak saying Jacob has unfinished business with his son Mark, then Jacob immediately contradicting him.
Tantrum Throwing: Cameron gets frustrated and trashes his room in "Unending" from being locked in the time-stopped ship for so long.
Tastes Like Chicken: In "The First Commandment", SG-1 is sitting around a campfire eating MREs.
Daniel: This tastes like chicken. Sam: So what's wrong with it? Daniel: It's macaroni and cheese.
Technobabble: Mostly courtesy of Carter, McKay, and a couple of others. O'Neill serves as a bit of a Greek Chorus when this happens, either interrupting Carter to ask a simple "yes or no" question, or else to irritatedly inform her that he does know what photosynthesis or supernovas are, thank you.
Technology Uplift: A frequent dilemma for the more advanced races is whether or not to do this. Most races are reluctant to provide Earth any advanced technology due to either bad prior experiences, such as the Tollan who in the past gave a lower-tech planet an unlimited energy source only for them to blow themselves, or believing Earth is not yet mature enough as a civilization. The main exceptions are the Asgard, who owe Earth, and the Tok'ra, with whom Earth was in an alliance. A episode also features the Aschen, a race that appear to do this but are doing so for their own ends.
The iris is used to prevent anything unwanted from coming through the Stargate.
As in many other settings, deflector shields block teleportation, and Ori motherships apparently have systems to prevent explosive devices being ringed aboard when the shields are dropped to fire the main cannon (the Korolev and Odyssey try it at the supergate battle in "Crusade", and Bra'tac tries it again later in "Flesh and Blood", and neither attempt is successful).
Subverted in "The Pegasus Project". The Daedalus is able to beam a warhead aboard a Wraith hive ship because the black hole is disrupting the countermeasures the Wraith have against Asgard teleporters.
Terminally Dependent Society: Jaffa carry a larval goa'uld symbiote in their stomach pouches, which grants them an increased lifespan and immunity from disease, but suppresses their own immune system. If the symbiote is removed, they grow ill and die within days. In season six the SGC discovers the medicine tretonin, which can replicate the healing effects of the Goa'uld, but this simply transfers the dependency to an artificial chemical.
That Man Is Dead: At the conclusion of "Cor-ai", Hanno, who has spent the episode trying to get Teal'c executed for killing his father, allows him to go free after Teal'c had helped save him and his people from the Goa'uld. When Teal'c asks why, since he did kill his father, Hanno explains the he did not, as the Jaffa who did is dead.
Theme Naming: Earth's starships tend to follow this convention. The American-crewed vessels are named after mythological figures (the exception being Stargate Universe's George Hammond, which was renamed from the Phoenix), while the Russian- and Chinese-crewed vessels tend to be Named After Somebody Famous.
During the wedding scene in "200", the organ is playing a combination of Mendelssohn's Wedding March (the "standard" wedding composition) and the show's theme.
They Called Me Mad!: Daniel Jackson and his grandfather, plus several different scientists encountered off-world who were studying their respective Stargates and/or artefacts left behind by the various alien cultures.
Throat Light: When a person is being tortured with the Goa'uld cattle-prod device, light shines out of their mouths and eyes. Richard Dean Anderson did not like this visual effect, and would close his eyes whenever Jack O'Neill was being tortured in order to keep it from being used.
Tidally Locked Planet: The Planet of the Week in "The Broca Divide" was tidally locked with its sun so one side was always light, the other always in darkness. The civilization lived in the light side near the terminator, where it was temperate. A plague that made humans devolve into Neandertalesque creatures had broken out, and the infected were banished to the dark side of the planet. The gate happened to be in the darker parts of the terminator.
Time-Compression Montage: "Unending", the series finale, had one of these, set to Creedence Clearwater Revival's "Have You Ever Seen the Rain?"
Title Drop: Quite apart from the fact that there's one every time somebody mentions SG-1, the individual episodes include their own titles in dialogue very frequently.
Tomato in the Mirror: In "Tin Man", where after visiting the ruins of a technologically advanced society, the team comes back through the Stargate only to discover that they are robot copies of the originals.
Tomboyish Name: Samantha "Sam" Carter. In the pilot O'Neill mistook her for a man when he was told that Sam Carter was their foremost expert on the stargate, and in a later episode when is asked what her name means, she responded that it means her dad wanted a boy.
Daniel goes from a charming Nice Guy to a manipulative Handsome Devil with aggressive urges, after his repeat exposure to a Goa'uld sarcophagus whilst being uninjured, causes him to become addicted to its effects. It lasts only one episode, as he quickly is forced to go cold turkey.
Daniel again, when Shifu grants him a vision of what he'd become if he gained all the knowledge of the Goa'uld.
After gaining their independence from the Goa'uld in "Threads", the Free Jaffa Nation spend most of Series 9 and 10 being a group of ungrateful bastards to their former allies, treating the Tau'ri and the Tok'ra with open suspicion and mistrust and downplaying their vital role in the fall of the System Lords at nearly every turn.
A great example of the latter occurs in "Ex Deus Machina", where the Jaffa don't see anything wrong with repeatedly infringing upon Earth's sovereign territory to apprehend Ba'al, nearly blowing the masquerade wide open in the process. In comparison, whenever the Tau'ri venture to Dakara, they attempt to be diplomatic and respectful and when it's made clear that they've outstayed their welcome, they leave!
Torture Is Ineffective: In "Talion", Teal'c tortures a man involved in several bombings against the Free Jaffa Nation but gets little useful information (admittedly he was doing it partly to punish him). In prior episodes his technique of sitting across the table from the prisoner and simply glaring at them until they talk was a hell of a lot more effective.
In season 1 episode "Hathor", tranquilizer guns are used against the entranced SGC guards to neutralize them non-lethally.
The Salish Indians in episode "Spirits" take out SG-1 with blowpipes firing tranquillizer darts.
In "Redemption, Part 1", Captain Hagman (the 9th temporary replacement for Daniel Jackson) gets hit while SG-1 is Chased by Angry Natives.
Osiris is twice shot by a tranquillizer dart tipped with a Goa'uld-specific sedative. The second time, this leads to her capture.
SG-1 later uses a trinium tranq dart tipped with the same sedative to try and subdue a Kull warrior. It penetrates the armor, but doesn't even slow it down.
Translation Convention: The episodes "Summit" and "Last Stand" are explicitly stated to be spoken in Goa'uld, but all the dialogue is in English for the convenience of the audience. Several other episodes have dialogue that is implied to be the same, particularly when aliens speak amongst themselves.
Translator Microbes: Though never mentioned in the show, the novels based on the series reveal that the Stargates somehow allow people from different planets to understand one another. The characters themselves do not understand how it works, nor why it works sometimes but not others, but it explains why almost all the aliens speak English. Although one could speculate that this might have something to do with the fact that Earth's Stargate operates with a jury-rigged together dialing device, which ignores about 200 or so command signals that it's meant to use during operation. It's possible whatever causes this effect on their own Gate has been left a little bit iffy as a result.
Transplanted Humans: The majority of the inhabitants of the Milky Way are humans that the Goa'uld transplanted from Earth to serve as their labor force. The name used throughout SG-1 to refer to the people of Earth, "Tau'ri", translates as "those of the first world", since Earth is where everybody else originally came from.
Trial by Combat: The Jaffa believe firmly in the concept of Asskicking Equals Authority; if a Jaffa believes that he is more worthy of leading than the Jaffa in charge he may challenge him to ritual combat for the position of leader.
Typhoid Mary: The Priors managed to sneak their plague onto the Earth by turning an SGC lieutenant into an asymptomatic carrier, passing through quarantine because he exhibited no signs of the disease before he began passing it on to civilians he encountered outside the base.
Un-Cancelled: In-Universe, Wormhole X-Treme! was picked up for a movie in "200", five years after being cancelled after the third episode. Then the network dropped the movie and started the series back up again, and it ran for ten seasons before getting a green light on the movie again.
Five or six different offworld-born humans are granted asylum by the Stargate Program, as is a clone of O'Neill. As this is the United States government we're talking about, dummying up the papers wouldn't be much of an issue; the show specifically mentions in "Singularity" the backstory they gave Cassandra Fraiser.
In season nine, Ba'al and a few minor Goa'uld turn up in control of several major Earth corporations. The answer is in how they got there: by capturing and infesting The Trust in season 8, a group with powerful friends in the US government.
SG-1 abandons Replicator Fifth to an eternal prison in a time bubble after Fifth betrayed his brethren to help them. This is heavily weighed before they follow their orders.
After gaining their freedom from the Goa'uld, the Free Jaffa Nation engage in this a lot during Series 9 and 10.
Unique Pilot Title Sequence: "Children of the Gods" imitates the movie with a long pan over the mask of Ra. After that, they used cut-together clips from season 1, changing it only when the main cast changed. The DVD releases of seasons 4 and 5 use the "Children of the Gods" title sequence for some reason.
The heavy metal naquadah, which is the material the Stargate is composed of, does not naturally exist within the Solar System and is heavily involved in Goa'uld technology. Its nonexistence in the Solar System is a minor plot point in "Fail Safe". Carter realizes that the asteroid they are trying to stop from hitting Earth has a core of naquadah, leading her to the conclusion that it was imported by the Goa'uld to circumvent the Protected Planets Treaty with a manufactured natural disaster. Naquadah can be converted to naquadria, a more powerful but unstable variant, when it is exposed to certain radiation.
Trinium is a silvery metal that is very light and about a hundred times stronger than steel. The Tau'ri and Asgard use it in the hulls of Prometheus-, Daedalus-, and O'Neill-class warships, while the Tollans combine it with other substances in several pieces of Applied Phlebotinum (including the device that lets them walk through walls). And the Tsalish use it for arrowheads.
In "A Matter of Time", when a black hole forms from a pre-existing star, its gravity suddenly and inexplicably increases. An actual black hole's formation occurs when a star's mass collapses into a singularity, but its gravity doesn't suddenly increase as depicted in the episode: it has the same mass and gravity, just in a much smaller volume.
Sam: "The singularity is about to explode"? Martin: Yes. Sam: Everything about that statement is wrong.
Unresolved Sexual Tension: Carter and O'Neill. Word of God states that just about the nanosecond Jack retired, he and Sam got it together and got it on. (Alternatively, Word of a Different God states that they got together after "Threads" and have merely kept the relationship quiet ever since.) A deleted scene from the Stargate Atlantis episode "Trio" also pretty much confirms that it finally got resolved.
This causes the pair to be mistaken for brainwashed assassins in "Divide and Conquer", when a Tok'ra Lie Detector gets a false positive because they do not admit the real reason he would not leave her behind on the previous mission. The writers play with this hilariously in "Window of Opportunity". During one timeline cycle, since neither Carter nor, more importantly, General Hammond, will remember it after the timeline resets, O'Neill resigns his commission so he can finally kiss Carter.
Unsettling Gender-Reveal: Inverted. Daniel looks rather relieved when the Kull Warrior who has him tied up in "Prometheus Unbound", who said Daniel was the "most attractive" human, turns out to be the human, and female, Vala.
The Unsmile: In the first season, when Teal'c was still getting angry looks for being a Jaffa, Daniel explained that he was a friend and told him to smile. The resulting facial movement was... off.
Unusually Uninteresting Sight: The team often walks right into settlements with guns at the ready. Rarely does anyone seem to have any trouble with this, though it does pop up when the plot demands it.
Unwanted Rescue: In "The Other Guys", SG-1 allowed themselves to be captured on purpose in order to make contact with a Tok'ra that was undercover as a Goa'uld working for Anubis. They are somewhat perturbed when Coombs and Felger stow away aboard their prison ship in order to rescue them.
Vichy Earth: The Aschen supposedly invite the Earth's peoples to join an advanced alien confederation. The whole subsequent genocide and sterilization plot was secret from everybody except for the highest Aschen and some collaborating human leaders.
Averted with Machello in "Holiday". He's technically not evil, but he is the antagonist of the episode. His attempts to blend into American society don't entirely work, with the homeless man he befriends convinced he's a Gulf War vet suffering from severe PTSD.
Played straight with Ba'al. After his defeat in season 8 he eventually turns up on Earth, undetected and fairly successful. ("Fairly successful", as in the CEO of a major corporation.) He blends in so well the only reason the SGC finds out about him is he intentionally exposes himself.
Virtual Reality Interrogation: Season 2, episode 22 is a Clip Show where one of the plotlines is where O'Neill, Carter and Daniel awaken from stasis in what appears to be the SGC, almost 79 years in the future. They discover it is actually a Goa'uld hoax by Hathor.
Wasn't That Fun?: Used in the ninth season; after the team has posed as drug dealers, been captured by drug dealers, got beaten up, captured by the Lucian Alliance, etc., they finally get back to Earth.
Mitchell: We have the best jobs in the world. (beat) Sam: I'm going to hit the showers. (exits) Daniel: I'm going to find the doctor. (exits) Teal'c: We are indeed suitably employed, Colonel Mitchell. (exits) Mitchell: Yeah, good day.
The Watson: Jonas Quinn joined the cast in season six from an alien planet, requiring him to be filled in on past SGC missions and esoteric parts of Earth history. This was particularly helpful since season six was the season where they began connecting and expanding on a lot of previously introduced continuity, primarily the concepts of Ascension, the Ancients and the greater society of the Goa'uld, so he could help bring new viewers up to speed.
The first is the energy weapon for killing Anubis'Kull warriors, which is of indeterminate use against anything else but will kill Kull in a couple shots by negating the Ancient phlebotinum that brought them to life in the first place.
The second is the Replicator disruptor (and the anti-Replicator gun adapted from it in Stargate Atlantis to fight the Asurans), a weapon built using Ancient knowledge that disrupts the ability of individual Replicator blocks to communicate with each other.
The most impressive one, though, is certainly the Sangraal (the Holy Grail itself), designed by Merlin to wipe out all the ascended beings from a galaxy. It is finally used on the Ori in season 10 episode "The Shroud", but it isn't before the movie The Ark of Truth that its efficiency is confirmed.
We Can Rule Together: Nirrti attempts this with Jonas Quinn in "Metamorphosis" once she realizes he is her best shot at creating a Hok'tar (an advanced host with Psychic Powers). Jonas' response to the offer is that, if he was given such powers, the very first thing he'd do would be to destroy Nirrti.
We Have Forgotten the Phlebotinum: Several episodes deal with the team needing something from another base, planet, or needing a bit of MacGyvering to make a new doohickey, to solve whatever problem they're currently facing.
A Weighty Aesop: Used in a throwaway scene in season 6. As the season begins, alien refugee Jonas Quinn is shown eating in nearly every scene at the SGC. He later mentions to Carter that he's really gotten into this "traditional all-American food". Carter points out to him that America has another tradition: hardened arteries. This aspect of Jonas' character was quietly dropped after that.
Wham Episode: In the episode "Heroes", the death of Dr. Janet Fraiser. To add extra oomph, Killed Off for Real is played with in this episode, as two characters (including an Red Shirt) receive potentially fatal wounds before it is revealed quite shockingly that Janet, whom the viewer does not even know got injured, is the one who actually died.
Nao'nak: From this day forth I will reclaim my real name. (removes helmet) Apophis.
In 8.18 "Threads", at the Astral Diner, a pathway to Ascension, Daniel Jackson has been conversing with Oma Desala and another ascended man named Jim who has periodically been providing him with information. Near the end Daniel asks Jim why he antagonizes Oma so much.
Jim: Who, me? I have nothing against Oma. I think she's great! Hell, she's the one who helped me ascend.
When Things Spin, Science Happens: The Stargate itself, which has a center ring that spins when SG-1 is dialing. Interestingly, gates with functional DHDs don't spin, suggesting the spinning might be some sort of manual control. This was Lampshaded in the 200th episode during the marionettes parody sequence: as they were preparing to activate the Stargate for the first time, Gen. Hammond demanded that they make it spin, as it would be so much cooler that way.
"Moebius", which was also meant to be the series finale, revisited Ancient Egypt under Ra's rule, and Apophis's prison on Chulak from the pilot episode — the alternate timeline SG-1 even got to recruit Teal'c again.
Also the climax of The Ark of Truth takes place in the City of the Ori, a place that Daniel and Vala visited early on in the ninth season. While not the start of the show itself, it was the start of the Ori storyline.
Within the show's story, when the Jaffa kicked the Goa'uld's asses once and for all, the final battle took place on Dakara and they chose Dakara as the capital of their new country; for the express reason that it was also the place where they first became slaves. It was also a significant religious site like Mecca is to Muslims.
Who Names Their Kid "Dude"?: Teal'c gets asked this regarding his own name in "Past and Present". He takes it in stride and answers that his father did, and that his name means "strength".
Dr. Jackson: And the last one is Lord Yu. Dr. Weir: Yu? Dr. Jackson: Don't. Every joke, every pun, done to death. Seriously.
After Ba'al starts cloning himself in the later seasons, Ba'al-related puns start to crop up.
Cam: We've got a full count, sir. Two strikes, three Ba'als.
Who Watches the Watchmen?: Colonel Simmons of the NID explains the organization's mandate to O'Neill: Providing civilian oversight to top-secret military projects. Jack, however, wonders who oversees them.
Who Writes This Crap?!: When O'Neill summarizes his history to the memory-erased Martin, at the opening of act four, Martin comments that that is the worst Act Four Opener he has ever heard.
O'Neill: (referring to Apophis) Somebody's gotta teach that guy how to die.
Will They or Won't They?: In several episodes, the writers play with romantic tension between O'Neill and Carter, and two different Alternate Reality versions of Carter are either engaged or married to O'Neill. The "won't they" wins out in the prime reality largely because for most of the show's run, O'Neill is Carter's direct superior and is thus barred from pursuing her by the Air Force's anti-fraternization rules.
The Atoniek armbands, which grant the human members of SG-1 super strength, speed and senses, also impair their judgement and decision-making skills. They never quite reach the full level of "insanity", but they begin to disobey orders (well, more than usual) and recklessly use their powers, starting a Bar Brawl and inadvertently hospitalizing SGC personnel.
In "Absolute Power", Shifu, the Harcesis Child, gave Daniel a vision of what would happen if he gave Daniel the colletive knowledge of the Goa'uld. Daniel would become a despot who would murder millions of innocents and regularly fantasize about being a Goa'uld.
Within Parameters: Justified. Sam notices that the power level of a force shield surrounding the town they are in (protecting it from the poisonous wasteland outside) is dropping. The other scientist present insists it is nothing. He is being brainwashed by the computer.
Won't Take "Yes" for an Answer: When the SGC was first founded and its members began to wonder what kind of institution it would become, Daniel pushed heavily for the anthropological study of the civilizations they encounter to be given just as much a priority as military development. He was so ready to do battle with the pig-headed, stubborn military minds of the base that Hammond could not get out the words to tell him that he agreed and would be following up with studies of the people they encountered.
Played with in "Absolute Power" with Daniel Jackson. In the episode, Daniel is trying to sensitively obtain information about the Goa'uld from the Harcesis, Shifu, who touches his head in an apparently hostile act, as it renders him unconscious. When he awakens, he proceeds to have all of the needed knowledge revealed to him and proceeds to build the weapon that would apparently defend the Earth, but at the cost of having become evil. He fantasizes about very violent things until, finally, his goal is met. He then proceeds to take over the most powerful weapon in the world from his Supervillain Lair and destroy Moscow before waking up and realizing that having absolute power to defeat the Goa'uld in one fell swoop is not such a good idea after all. He wakes up to discover that it was All Just a Dream, but during the episode, it was implied that Woobie, Destroyer of Worlds is actually simply a part of his subconscious, with or without special knowledge. Not surprising, really.
The Worf Barrage: In the episode "Beachhead", an Ori force-field is powered by the weapons fired at it.
Workaholic: Carter has little to no life outside of the SGC, and spends her free time in her lab on the base running various experiments. In "Nemesis", she turns down O'Neill's offer to join him at his cabin for a fishing trip by saying that experimenting with new tech in her lab really is her idea of fun. When she is finally ordered to spend some time away from work in "Ascension", she comments that she really does not have anything else to do.
World-Healing Wave: The original purpose of the Dakara Superweapon created by the Ancients, which restarted life in the Milky Way Galaxy after the Plague forced the Ancients to leave. As its current name suggests, no-one uses it for such benevolent purposes during the series.
World War III: The Goa'uld try to start one between the US and Russia in "Full Alert" but cooler heads prevail.
Worthy Opponent: Arkad wants to be Teal'c's famed foe, and explains that he admired Teal'c's bravery and skill even when Teal'c killed his parents, but both Teal'c and Bra'tac have nothing but contempt for him.
Wrong Genre Savvy: When the team is faced with a very real dragon, Col. Mitchell suddenly decides he is some kind of dracologist and plans to kill it by setting off a brick of C-4 underneath it, since "that's where dragons are weakest." The dragon proves him to be very wrong.
Xtreme Kool Letterz: Martin explains that the title "Wormhole X-Treme!" was a marketing decision, since shows with the letter "x" in their title do better than other shows.
In the series finale, Sam does this to keep the Odyssey from getting blown to smithereens while she uses the extra time to try and figure a way out of danger. The good news is that she succeeds. The bad news is that it takes her fifty years.
Ye Olde Butcherede Englishe: Averted. When SG-1 finds a tablet written in Middle English it is indecipherable to O'Neill and can only be identified as English by Daniel, the archaeologist.
"Children of the Gods" provides the page quote. Jack answered Hammond's question about whether he could win against Apophis' Jaffa in a reasonably confident tone of voice, but by this point Air Force personnel have been torn up pretty badly by the Jaffa both times they've met them so you can understand Hammond not sharing Jack's confidence:
Hammond: Colonel, you've had the most experience in fighting this hostile. Assuming you have to defend yourself in the field, are you up to it? Jack: We beat 'em once. Hammond: I'll take that as a "maybe".
After beaming onto an enemy ship and coming under heavy fire, Colonel Mitchell announces his presence and asks the enemy soldiers to surrender. When they don't stop shooting, he says "That's a no" and starts returning fire.
"Spirits" opens with O'Neill wounded by an arrow through the shoulder, forcing Carter to take command of SG-1 when they are sent through the gate to discover its source. O'Neill observes that it is her first command, commenting "cool."
In "Lost City", General Hammond authorizes Carter to take command of SG-1 if she determines that the Ancient knowledge downloaded in O'Neill's mind is beginning to compromise his judgement. When she tells O'Neill of her orders, he says he understands and that she should take command now instead of waiting for him to lose control.
You Are Not Ready: The standard explanation for why advanced alien races will not share their technology with Earth; the Asgard specifically explain that humanity is "too young." However, unlike most examples of the trope, the Asgard help humans get ready. They gradually introduced the Tau'ri to their technology, first giving them devices and later showing how to manufacture this by themselves, so that they could appreciate their power and learn to handle them appropriately. This culminates with the dying Asgard race leaving humanity a matrix containing all their advanced technology.
Kasuf says in "Forever in a Day" that Sha're/Amonet's son is harcesis, "the one who holds the secrets."
In "A Hundred Days", Daniel explains that the "fire rain" is called a "falling star" on Earth, and Tealc' then gives the Goa'uld name of the phenomena. After a moment, Daniel translates that to "falling star".
Because of his Mook-Face Turn in the pilot, Teal'c is unable to openly return to Chulak as long as Apophis rules there. Even after there is no longer an opposition to his return he remains on Earth, since he sees the Tau'ri as the best hope for overthrowing the Goa'uld.
In "A Hundred Days", Jack is trapped offworld for three months because a meteorite buries the gate. He's only able to return when the SGC manages to partially excavate it by firing a particle beam through it, then send Teal'c through to dig the rest of the way to the surface.
Jonas Quinn spent season six living on Earth and unable to return to his home, the nation Kelowna on the planet Langara, because he stole a quantity of naquadriah to give to the SGC.
You Didn't Ask: In "Brief Candle" Daniel encounters Linear-A script, which has never been fully deciphered on Earth, but Teal'c recognizes it as an old dialect of Goa'uld. When he is able to read part of the script, Daniel asks why he did not mention it before, and Teal'c responds that Daniel "did not inquire."
You Had Us Worried There: O'Neill jumping an about-to-explode Stargate away from the Earth, with a scare about whether or not he was able to eject.
Mitchell Kosterman first appears in "Seth" as ATF Special Agent James Hamner, then again in "Heroes" as Colonel Tom Rundell.
Dion Johnstone played a total of seven roles over the course of the show, often under heavy makeup. He played (in order): Captain Nelson in "Rules of Engagement", Na'onak in "Jolinar's Memory" and "The Devil You Know" (before his mask was removed and a new actor took over), an unnamed alien in "Foothold" (identified as "Alien #2"), Chaka in "The First Ones" and "Beast of Burden", Lieutenant Tyler in "The Fifth Man", Wodan in "Metamorphosis" and Captain Warrick Finn in "Forsaken".invoked
David Palffy portrayed the Goa'uld Sokar in season three and returned as the robe-shrouded incorporeal form of Anubis from the end of season five up to "Lost City". He continued to voice Anubis through season 8, with the exception of Anubis' ascended form in the diner between worlds.
Patrick Currie played three separate roles, but never actually looked the same in any of them: Two of his three roles were in heavy makeup as aliens. He was Chaka in "Enemy Mine", Eamon in "Space Race" and the Replicator Fifth in multiple episodes in seasons six and eight.
Anne Marie DeLuise played Farrel in "The Other Side" and returned as Amy Vanderburg in "Bounty".
David Lovgren first appeared as Va'lar in the episode "Threshold", reappearing as Darrell Grimes in "Bounty".
Mike Dopud plays Russian Air Force Col. Ruslan Chernoshev in "Full Alert" and Bounty Hunter Odai Ventrell in "Bounty". He then reappears as Lucian Alliance member Varro in Stargate Universe.
Peter Bryant played Teal'c's old friend Fro'tak in "Family", then rogue NID agent Hoskins in "Affinity" and "Endgame".
Alessandro Juliani played Eliam in "Scorched Earth" and Katep in "Moebius Part 1 & 2"
Younger Than They Look: The people of "Brief Candle" are all being artificially aged by Goa'uld technology at a rate of approximately one year per day. When he discovers this, O'Neill is rather disturbed to learn that the woman he slept with was not thirty years old, but thirty days old.
Your Approval Fills Me with Shame: In "Beachhead", everyone is understandably perturbed when minor Goa'uld Nerus attempt to butter them up by congratulating them for their role in ending the reign of the System Lords.
Your Costume Needs Work: When O'Neill is on the set of Wormhole X-Treme! he goes to the security office to get information on recent visitors to the studio. He is first told how to find the auditions, and then needs to add "really" after he explains that he is from the actual Air Force.
You're Not My Mother: Cassandra says it to her adoptive mother, Dr. Fraiser, in "Rite of Passage". To be fair, the teenager was quite feverish and stressed from the effects of Nirrti's retrovirus at the time.
Your Mom: In the fifth season episode "Failsafe", O'Neill and Jackson recount how a particular negotiation with the Asgard went south.
O'Neill: ... And after that, I kind of lost my temper. Hammond: What exactly does that mean? Jackson: Let's just say Jack made a reference to Freyr's mother.