Age Is Relative: Despite great variations in their appearance, most of the senshi are aged within a year of each other, with any grade differences being a product of also being transfer students. This is obscured the fact artists draw Haruka and Michiru as much older looking than the other characters, who gushed about how mature they seemed. The Nineties anime even poked fun at the idea that Haruka's hobby of car driving doesn't really make legal sense.
Alien Abduction: Crimson Rubeus, Prince Demand and Wiseman of the Black Moon Clan, aliens from the planet Nemesis, succeed in abducting multiple protagonists with some variation by medium.
In the Black Moon arc of the manga, three of the Sailor Senshi (Sailors Mercury, Mars, and Jupiter) are captured by Rubeus; only Sailor Venus and Sailor Moon remain. Eventually, Sailor Moon is captured as well when she is teleported from Crystal Tokyo to Planet Nemesis. There, Demand tries to brainwash her with his "third eye", but fails, and they soon free themselves en masse, only to have Wiseman kidnap Moon's young charge, Chibi-Usa, to successfully brainwash her for his own purposes.
In Sailor Moon R, Crimson Rubeus captures all the Sailor Senshi except Sailor Moon, who frees them after defeating Rubeus. In a later episode, Prince Demand captures Sailor Moon and tries to brainwash her into being his bride, but Tuxedo Mask intervenes and saves her. One episode later, Wiseman kidnaps Chibi-Usa as in the manga.
Amusing Injuries: There's a slapstick routine in Act/Episode 1 involving Usagi trying to "Sailor V kick" Shingo for irritating her just after she got booted from the house for failing a test. Usagi misses and kicks the closed door, then clutches her foot in pain and melodramatically wails to be let in.
Anachronism Stew: The names of the planets in our solar system were given to them well into recorded history, and relatively arbitrarily at that. The senshi, on the other hand, have been around for eons. It really makes no sense that a senshi's powers would be based on the powers of a deity her planet was named after long after she came into being.
In the manga, all the Senshi have ancient castles named after moons belonging to their respective planets; the exceptions are Mercury and Venus, whose castles are named after American spacecraft sent to probe those planets in the latter half of the 20th century...
One possible explanation is that the myths and Roman names came from Sailor Senshi.
There's a theory which handwaves the anachronisms via Sailor Pluto and her father.
The Soldier's powers being based on the deity the planet was named after only applies to Jupiter's lightening attacks and Venus' love-based attacks. All the other Soldiers have attacks based on the Japanese name for the planet. For example, Mercury in Japanese is Suisei, which literally means "water star." Hence, Sailor Mercury has water-based attacks.
Venus and Jupiter DO have the name-themed attacks as well though. For Jupiter, it's plants. (Flower Hurricane, Coconut Cyclone) Venus has Metal(Venus Love-Me chain, Wink Chain Sword, Manga version of Love and Beauty Shock_.
Shingo's more of an aversion really, most of their problems are caused by his sister and despite their bickering he's shown to care quite deeply for her. One episode even showed that he was fairly well-liked amongst Usagi's friends, which is impressive given their exasperation with her sometimes.
As Long as There Is Evil: Chaos. In the manga, as long as stars are born, Chaos will continue to be reborn as well. In the anime, it simply returns to the heart of all humans.
Art Evolution: One of the most notable examples is Shingo, who is one of the few characters to visibly age between seasons. He starts out drawn much like other children are in anime and manga with short limbs and very rounded features. Later on he looks (appropriately) more like a pre-teen, he's had something of a growth spurt (making him only slightly shorter than his sister) and his face has lengthened too. As a general example for everyone else, compare this screenshot of Sailor Moon herself◊ from Season 1 to this one◊ from Season 4.
Part of this may be due to an undefined timeline, particularly due to two major continuity hiccups which occur in the show. To complicate matters, the anime, which was produced over 5 years, seems to only really take place over the course of three years. Which three years is hard to say as an onscreen date, printed on a visible newspaper in season 1 says it's 1992, while a similar date in Stars says 1996.
Back from the Dead: Done as a reset button. This is only vaguely defined and downplayed in the show for the sake of tension. However, healing powers up to and including esurrection is one of Sailor Moon's principal abilities in the manga, so much so that the Senshi actually plan to have Sailor Saturn kill everyone on earth, just so Sailor Moon can bring back everyone but the bad guys. This is also played with at the end of the First, Second and Fifth story arc.
Belligerent Sexual Tension: Usagi and Mamoru initially meet when she hits Mamoru in the head with a test paper, leading to Mamoru insulting her test score and Usagi screaming at how much she hates him. This progressed in both to rather heated meetings, though it became quickly clear the characters were developing an attraction to each other. This was drawn out much longer in the anime, and each encounter even had its own theme music. In both mediums, however, Usagi and Mamoru eventually realized they were not only Sailor Moon and Tuxedo Mask, who share a more tender and heroic relationship in combat, but also learn they were lovers in the distant past as Princess Serenity and Prince Endymion. Unlike a great deal of these examples, the tension is actually resolved rather early in the series and the drama with the pair after that comes from outside forces trying to force them apart.
Played with in the fifth season of the anime, where Seiya (who is on the receiving end) assumes this is what Usagi does when she's attracted to someone before realizing she's not interested in him.
Brainwashed and Crazy: Most notably Mamoru as Prince Endymion in Season One. In the manga it's somewhat of a recurring theme for him. In the manga, the original Quirky Miniboss Squad of the Dark Kingdom also falls into this.
And in the manga, Amazoness Quartet and, in the final arc, just about every character from the present, except Usagi.
Notably, in the anime victims always manage to break out of this. In the manga, not nearly.
By the Power of Grayskull!: "[Planet] [Something] Power, Make-up!" The dub usually just took off the "Make-up!", but sometimes you got things like "Moon Cosmic Dream Action!"
Calling Your Attacks: All the Sailor Senshi. They don't have to call out their attack names (we know that because they don't always do it), but they usually say the name. Theories on why vary.
The dub also gives multiple names to single attacks. For example Sailor Moon's finishing attack in R (Moon Princess Halation) has 3 different names in the dub:
Moon Scepter Elimination (episodes 45-65 and 83)
Moon Scepter Activation (episodes 66-82)
Moon Princess Elimination (R movie)
Can't Catch Up: Poor Mamoru. Let's just say there's no Super/Eternal Tuxedo Mask. Not shockingly, he gets kidnapped/killed a lot.
Justified in that Mamoru is technically just a human while the senshi are Human Aliens.
Cats Are Magic: The characters find out they are Sailor Senshi with magic powers because two talking cats with crescent moons on their foreheads, Artemis and Luna, appear to inform them and guide them as they try to save the world. They can even make magical items appear by doing backflips.
Chandler's Law: The introduction of Chibi-Usa. The series was initially planned to end after it's first arc. How was it extended? By a little girl falling from the sky and aiming a gun at Usagi. It was more pronounced in the manga, where the scene was a Cliffhanger ending.
Cryptic Background Reference: StarS is made of this trope. The anime teases you to a degree with the idea of there being countless senshi and planets out there; the manga offers you brief glimpses of alien worlds, including one where the inhabitants apparently have fish for heads. Not fish heads, fish for heads.
Death Is Cheap: One of Sailor Moon's powers is explicitly resurrection, so expect main characters to die at least once per storyline. This is more prevalent in the manga than in the anime; in the latter, Sailor Moon cannot really control this power, so the Senshi tend to die a lot less often.
Distressed Dude: Poor, poor Tuxedo Mask. Does not help, that female Big Bads except anime Galaxia seem to be fixated on turning him into their lapdog. Manga Galaxia forces him to kiss her boots, then kills him again. Just to mess with Usagi.
Elemental Rock-Paper-Scissors: Sometimes, as in the S movie where Ami's water attacks (More specifically, attacks that result in ice instead of water) do nothing to the ice-powered villain; sometimes not.
The End of the World as We Know It: Looms as a threat every damn arc/season. Actually happens a few times. The last season involved this for the entire Milky Way galaxy. After the final battle, only Sailor Moon is left alive in both versions. (In the anime, the Starlights and Galaxia also survive; in the manga, Chibimoon and the Sailor Quartetto come from the future and also live.) The entire galaxy gets better, though.
Epileptic Trees: An in-universe example, when Chibichibi first appeared the inner senshi began spinning a theory the minute they met her that she was Usagi and Mamoru's second daughter from the future who got jealous from hearing about Chibi-usa's adventures in the past and decided to go back to have a few of her own, which was promptly jossed by Setsuna showing up. The manga version has this jossed by Queens of the Silver Millenum only being able to have one daughter and Chibi-usa josses it being her daughter stating she didn't feel any connection to ChibiChibi.
Everything's Better with Princesses: There's Princess Serenity, and in the manga and English dub, the inner senshi are all princesses as well. The Outers are also Princesses in the manga. Technically speaking, every series of senshi throughout the galaxy has a true princess they protect.
The author often refers to herself as "Princess Naoko."
Foreshadowing: In both the manga and anime, Chibi-Usa wants to make a copy of a grail she once saw in her mother's room out of clay as a school project. In the manga she's actually called out on this and asked if it was something Sailor Moon used for an attack, but Chibi-Usa doesn't know. What she ends up creating eventually turns out to be a replica of the Holy Grail, the object Sailor Moon uses to become Super Sailor Moon.
In the first chapter of the manga, Sailor Moon can use her mask as a Spider-Sense to see that Naru is in trouble. The anime adaptation of this story showed the jewels in her hair blinking and projecting Naru's cries for help, alerting her to the same circumstances. Despite how obviously useful this is, neither ability appears again.
The Disguise Pen only made a handful of appearances before being phased out early. The disguises themselves were usually not that necessary, though they did always turn Usagi into adult bodies, making it useful when she needed to slip into certain situations that required authority a teenage girl doesn't have. By Sailor Moon R (and the Black Moon arc of the manga), it was gone entirely as plots requiring this element were dropped. The Pen's final (and most memorable) appearence was in an episode in Sailor Moon S in which Sailor Venus used it to dress up as Sailor Moon.
Episode 5 of the anime showed Usagi using a skill called "Moon Tiara Stardust" that recycled the stock animation of her normal attack, but the effect allowed her to heal children possessed by the monster of the day. This power only showed up once, and by the time she was needed to heal humans again, she used the newly-acquired Moon Stick (which unlike "Moon Tiara Stardust" did actually show up in the manga.)
Four Is Death: The four Shitennou, the four Ayakashi Sisters, the first four of the Witches 5, the Amazoness Quartet, and the four members of Shadow Galactica under Galaxia (in the anime only - the manga had more).
If one considers all Sailor Senshi in Sailor Moon S and Sailor Moon Super S not introduced before to be Outer Senshi, then Sailor Saturn is literally death.
Frilly Upgrade: Contributes to the image. Eternal Sailor Moon takes this trope to ridiculous levels. At least Super Sailor Moon looked nice.
A God Am I: Happens a lot, at least once in every season. Beryl, Metaria, Wiseman, Mistress 9, Nehellenia, and Galaxia all increase their power to god status. Of course, they each get defeated by the Sailor Senshi. Subverted in that (in the anime) Esmeraude tried to become a godlike queen, using a crown that Wiseman gave her. Had she realized Wiseman deceitfully rendered the crown to turn the wearer into a mighty dragon, she probably wouldn't have taken it.
Grand Finale: Notably, the conclusion of the 1st arc was supposed to be this as the latter four seasons/arcs were not initially intended. The anime for example ends Season 1 with a Kill 'em All ending. Obviously everyone got better for Season 2.
The manga ending for the entire series is this in spades. It ends with Mamoru and Usagi's long awaited wedding, with all the main Sailor Senshi in attendance, sans Chibi Usa (unless you count the implication that she's already been conceived).
Hair Colors: Ami has blue hair. Setsuna and Michiru have different shades of green and Chibi-Usa's is pink (which is odd, when you consider that Mamoru is a brunette with blue highlights and Usagi is blonde). The hair colors aren't just metaphors either. Chibi-Usa's hair color is lampshaded several times.
Hand Blast: Sailor Venus' Crescent Beam emanates from her fingertip.
Human Resources: The show's first to arcs hinges on gathering human life force to feed a demonic force. Badiane's Black Dream Hole is powered by the "Sugar Energy" of sleeping children. See also Anatomy Of The Soul under the Anime section.
Depending on how liberal your view of the trope is, the harvesting of Heart Crystals in the second half of Sailor Moon S, or collecting the Star Seeds in Stars, may also count.
Might want to count Al and En's harvesting of human energy in R in there too.
Immortality Begins at Twenty: Averted; aging for magical characters is more of a matter of one's magical development than actual physical aging, which leads to Chibi-Usa looking like a kid at 900 and Sailor Saturn aging as the plot demands rather than on a timetable.
Invisible Parents: Ami's mother, Minako's Parents and Rei's Father are never shown in the anime. They all appear in the manga at least once, though Minako's are restricted to the Sailor V manga.
Invisible to Normals: Nobody notices that Usagi looks exactly like Sailor Moon. Subverted in the manga, where (gasp) Usagi realizes that Haruka Tenoh and Sailor Uranus look exactly alike, and calls Haruka out on it. Of course, this was mainly because Haruka kissed her in both identities and Usagi realized they had the same kiss - and realized that Haruka wasn't a man. In the manga, many people put two and two together faster. A handful of people figure out identities on their own in the anime - Minako's volleyball skills out her to an old friend. And while Shingo never recognizes Usagi and Sailor Moon to be one and the same, Usagi still hides from him when she appears as Sailor Moon.
They do not really attempt to hide in the manga because they rarely appear in public (Sailor V and early-chapters Sailor Moon wore masks, so they could afford some open acting), and most of the villains can sense their powers anyway. Usagi and Mamoru actually recognize each other as early as in Act 3, though only Mamoru takes it under consideration. Later, Motoki recognized the girls out of costume. The anime, on the other hand, was very, very bad about this.
On a smaller scale, Jadeite in the anime frequently shows up in front of Usagi without only the smallest attempt to disguise his appearance (i.e. wearing a hat or a pair of clear glasses)... and yet even after she's already met him, knows his real name, AND knows he's a bad guy, Usagi repeatedly fails to recognize him. He only attempts a proper disguise once (changing his hair and skin tone).
Similarly, Nephrite only changes his clothes when on Earth. In his case, he tries to keep a low profile and adopts a human identity in Masato Sanjouin. However, Usagi meets him in his first episode in his human identity and both she and Naru see him later as Nephrite and immediately recognize him as the same person. From this point on, the Senshi recognize him in his human identity - though strangely, they never tell anyone about the murderous millionaire living on the hill.
All four of the Ayakashi Sisters appear in both human identities and their actual identities in front of the main characters with the only difference being a change in clothes. No masks, nothing. Nobody ever recognizes them until they reveal themselves. Kooan in particular gets into Rei's shrine twice, in front of her and Yuuichirou, and Rei never recognizes her as Kooan - even when she's seen Kooan in a human identity.
The anime gives some implication that there's some actual Clark Kenting letting the girls get away with being seen by everyone but only rarely recognized, but its not consistent. This could presumably explain why the villains can keep getting away with running around in public without anyone spotting them.
Joshikousei - Sailor Moon is the patron saint of this trope.
Kid-Appeal Character: Two in the main cast - Ami was the Teen Genius of the Guardian Senshi, Chibi-Usa served as the Ankle Biter of the group when she joined the team as a Senshi after the Black Moon Arc. Chibi-Chibi has this to a greater extent in the anime.
Magic Music: In the anime, Al from the R series can summon his Cardians by playing a flute. The Three Lights' songs in the Stars season also allow them to send mental messages to people - with the side effect in the manga of drawing the attention of enemies.
The Woman Behind The Woman: Queen Metaria with Queen Beryl and Galaxia with Nehellina in Season 1 and Season 5 of the anime, respectively.
Mid-Season Upgrade: Usagi gaining the Silver Crystal, which powered up her Moon Healing Escalation in the first season, and gaining the Holy Grail which gave her a Super Mode, powering up her Moon Spiral Heart Attack into the Rainbow Moon Heart Ache in S.
And in Stars, Chibi Chibi upgraded Eternal Sailor Moon's Starlight Honeymoon Therapy Kiss attack to Silver Moon Crystal Power Kiss.
A lesser example, the Inner Senshi gaining their Super Forms.
Mind-Control Eyes: Seen in any brainwashed character, particularly Mamoru. Those who had their Pure Hearts stolen or were trapped by the Dead Moon Circus also had them until rescued.
Mind Rape: Dead Moon Circus did this to their victims in Super S. It's also how Chibi-Usa became Black Lady in R.
Mirror Morality Machine: The anime has lots of them. Beryl's brainwashing pod for Endymon which failed to make him completely evil. And Wiseman's "dark energy bath thingy" used on Chibi-Usa to make her into Black Lady (Wicked Lady in the English dub), which again, was not absolute. Finally, existence-support bracers that Shadow Galactica members wear, which effect, surprise, surprise, also was successfully resisted by Uranus and Neptune - not that it helped them any. Although the latter might be straight Mind Control devices.
Mood Whiplash: The series has a tendency to switch between lightheartedness, melodrama, and just plain silliness at the drop of a hat.
Morning Routine: Usagi waking up and rushing out of the house due to being late is a regular staple of the earlier episodes.
Mukokuseki: Yyyyyep. One of the really famous examples. Our main cast - consisting of two strawberry blondes, a light brunette, a natural blue and a single raven-hair, all with huge, variously-colored eyes (most being blue) and very light skin tones - are, in theory, all totally Japanese in ancestry. Passing them off as Americans in the original dub was not particularly difficult.
My Significance Sense Is Tingling: This happens a number of times with Rei, who is stated to possess psychic abilities and often notices when evil energies are present. This also occasionally happens with Mamoru in the anime, in particular when both he and Nephrite (in his Masato Sanjouin identity) pass by each other and both freeze up from the reaction. On one occasion, Luna also has a strong reaction to being in Jadeite's presence when he's in disguise and she's inside of a basket but not able to see him.
They get better in the manga though. Uranus and Neptune not so much in the anime though, as seen toward the end of Stars where they KILL Saturn and Pluto out of neccesity.
The Nineties: The franchise has become an iconic action series from the nineties, especially because at the time the idea of an all-female superhero action series aimed at both girls and boys was a novel concept. In the original anime and manga, early 90s fashions, technology, and lingo abound - to the point that later adaptations have had to update aspects of the show to stay contemporary.
Obstructive Code of Conduct: Pluto had three of them: 1: Don't let anyone use the Door of Space time. 2: Don't leave your post at The Door of Space-time. 3: Do not use your powers to stop time. Needless to say, she breaks all three of them.
Some fanfic authors, perhaps tongue-in-cheek, add: 4. Do not flirt with King Endymion.
Older Alter Ego: Early on, Usagi had a pen that let her age up and take on a disguise, such as a reporter, like older, traditional Magical Girls like Creamy Mami and Minky Momo. This was all but forgotten once other girls joined her, except it was used once in the R season.
Minako has a compact that serves the same purpose in the manga. It first appears in her own manga, Codename: Sailor V.
Omnicidal Maniac: Almost all of the Big Bads. In the manga, it's probably due to the fact that all of them are either the manifestations of the same being - the final Big Bad, Chaos - or under its influence.
Also the reason for Dead Lesbian Syndrome striking Sailors Uranus and Neptune a second time in Stars; they apparently didn't notice Galaxia wearing the very same brand of bracelet that can sustain you even after your star seed is removed.
Out-of-Clothes Experience: Pops up often, even remaining in the dub. Like in the transformation sequences, however, nothing explicit is observable. It is particularly relevant at the very end of the final episode of Stars, Sailor Moon spends the last episode completely naked and with wings on her back.
And you wonder why that season was never dubbed...
Pantyshot: A surprising amount of them, but it should be noted that they don't technically flash their panties because their wearing leotards. One time, it's not the viewers who get flashed, but Sailor Jupiter - something that rather draws her eye.
Paper-Thin Disguise: No-one can tell that the senshi and their normal selves are the same people because they are wearing tiaras. The world must just be one huge Idiot Ball.
Fanon holds that the Senshi have a some sort of magical glamour. This is supported by the fact that even Senshi can't see through them without it being revealed to them: When Uranus and Neptune show up the other senshi spend a number of episodes in the dark about their civilian forms despite having met them. The reverse happens when Pluto shows up in her civillan form the first time, a whole arc after being introduced as a senshi, Usagi needs to be clued in as to who she is at first. The same thing happens between the Starlights and the Senshi of earth, though in the starlights' case they are disguised as men (but with the exact same giant ponytails...)
Subverted in the R movie by Fiore.
Keep in mind that most of the normal people who would see both the Sailor Senshi and their civilian identities are usually busy trying not to get killed by whatever's attacking at the moment.
Somehow Usagi doesn't recognize a glasses-wearing Jadeite, despite meeting him the previous episode.
Parental Abandonment: Ami's father divorced and ran out on her mother years ago. Rei's dad is a high-ranking politician who dropped her off at the shrine after her mother died and only sees her for a monthly lunch date. Makoto's parents died some time in the past and she's lived on her own without legal guardians for a while. Uranus and Neptune already live together by themselves for unexplained reasons, and Pluto is a college student when she shows up in present day. Hotaru, on the other hand, is the daughter of one of the key villains in the 3rd arc, and her mother is dead. In the manga, Hotaru lives with the other Outers after her father's death at the hands of the senshi; in the anime, he loses all memory of his villainous activity and raises her until Pluto comes to get her in the last arc; afterwards she lives with the Outers to match up with the manga.
In the manga, Uranus and Neptune state that they have legal guardians/patrons.
Doesn't mean they have parents, though.
Don't forget, Mamoru's parents died in a car crash when he was six years old.
And Chibi-usa's situation as well. First her parents are both sent into a sort of sleep-stasis by the Black Moon clan, and she has to go forward into the future to save them herself. At various points in the R/Black Moon arc it's also hinted that even when they're awake she doesn't see her parents very often, and that Neo-Queen Serenity rarely even hugs or kisses her. Then her parents send her forward into the future to be trained as a Sailor Guardian.
Pimped-Out Dress: the Moon Princess dress; Neo-Queen Serenity's dress. In the manga all of the planetary princesses have their own pimped-out dresses.
Notably, however, Hotaru is physically younger after her age-up than she was intially.
Power Gives You Wings: Eternal Sailor Moon. Also in the climax of the 4th season in the anime. She jumps off a building to save a falling Chibi-Moon, the two of them collide with Pegasus and then sprout wings. She laters grows wings on her own during her "I Know You're in There Somewhere" Fight with Galaxia.
Power Trio: Sailor Moon, Sailor Mars, and Sailor Mercury for almost half of the 1st season. Also Sailors Uranus, Neptune, and Pluto once the three met up until the revival of Sailor Saturn. And The Amazon Trio. And the Sailor Starlights.
Praetorian Guard: The Guardian Senshi (Usagi's soldiers and protectors); the Shitennou (King Endymion's guardians, before they defected to Queen Beryl's side), and the Sailor Quartet (Chibi-Usa's guardians, manga only)
Put on a Bus: Uranus, Neptune, and Saturn (and Pluto to a lesser extent, though she's dead) in Super S; Chibi-Usa and Mamoru in Stars. Mamoru was put on a plane to be exact, a plane which was attacked mid-flight before ever reaching its destination. Lucky for him Death Is Cheap. Chibi-Usa gets caught in a paradox because of this and ceases to exist outside the memories of the Senshi. Even images of her in photos vanish. Only Mamoru's being put on a bus matched up with the manga, though it doesn't kill Chibi-Moon, just makes the future very unstable. She comes back at the end of the manga, but she's almost completely forgotten by the end of the anime.
Quirky Miniboss Squad: A requirement for villianous organizations. The Shitennou (Four heavenly kings) and The DD Girls both from the Dark Kingdom, The Ayakashi Sisters of the Black Moon Clan, The Witches 5 from the Death Busters, The Amazon Trio and Amazoness Quartet, both from the Dead Moon Circus in, Queen Badiane's unnamed Q.M.S. from "The Black Dream Hole", and the Sailor Animamates from Sailor Stars. Almost all are Bishōnen or Amazon Brigades.
Really Gets Around: Every man on the planet seems to remind Makoto of her ex-boyfriend/sempai.
Reed Richards Is Useless: Massively averted: in the future, Usagi resurrects the advanced civilization of her previous incarnation and changes the world forever.
Reincarnation: Everyone in the main cast, except Chibi-Usa and her cat Diana, who are the children of Usagi and Mamoru, and Luna and Artemis respectively.
In the manga, Pluto reincarnates backwards. She dies in the future, but her soul goes back in time and reincarnates some time period before the plot. She shows up after everyone comes back from said future. So presumably, she's going to wait until she dies in the future, and take her own place. At least this explains why she's not guarding the Time Door. The anime had less explanation of what happened.
Sailor Earth: Fanfic is crawling with these. Indirect Trope Namer. Canonically, there is no Sailor Earth as Mamoru has the Sailor Crystal representing Earth, and Word of God states only women can be sailor senshi.
Ironically, Naoko Takeuchi actually jossed the possibility of extrasolar senshi out there during the time the manga took place when it turned out that Sailor Galaxia had killed all of them except for Princess Kakyuu, the Sailor Starlights, and those who had joined Galaxia's side. (The anime, on the other hand, implies that there are others she hasn't killed or converted yet - also, considering how she goes off to restore the Starseeds to their rightful places once she's purged of Chaos at the end, it may mean that either other Senshi will represent such worlds, or their previous owners will be revived like the ones we saw.)
Sealed Cast in a Multipack: All the main cast members were killed in a great battle and reincarnated in the modern world. While they were't actually "sealed" the show follows the same pattern of tracking them down and unsealing them.
Simple Yet Opulent: The moon queen and moon princess dresses are grand but simple. Also, many evening dresses the girls wear are simple.
Slapstick Knows no Gender: Both the anime and the manga featured a great deal of physical comedy with the main characters, with Usagi as the most common victim of Amusing Injuries due to her cowardice in combat and her extreme clumsiness. Ironically, Mamoru, the only man in the least likely to be on the receiving end of slapstick humor (though he wasn't immune). The English dub of the anime censored a lot of it out for the first 65 episodes, though this eased off after the licensor switched.
Spell My Name with an S: Numerous thanks to the Theme Naming. Just look around this page for examples, and check the full entry there for why this page uses the names it does.
Stab the Sky: With scepters, not swords, but still fits this trope.
Stars Are Souls: The final scene of Sailor Moon has Usagi placing her hand over her heart and saying a star was just born (her daughter conceived).
Sailor Moon anime has an episode where a dreamy astronomy teacher references this trope during a show in which he and Taiki are participating. He believes that people become stars when they die. Taiki gets annoyed and says that stars can only be made by living people. Particularly interesting because in Sailor Moon a senshi's Starseed is her essence — this is what Taiki is referencing in this case. But a senshi can be reborn after death as long as her Starseed intact, so it's effectively the same thing as a soul. So it is a reference to this trope, but with a tweaked meaning.
Super Mode: Sailor Moon gets one during Season 3 from The Holy Grail with which to save the world from evil. Super Sailor Moon came with a butterfly motif, had a stronger version of regular Sailor Moon's attack at the time and usually transformed back into regular Sailor Moon not long after performing said attack. This version has an altered uniform with new hairclips, transparent shoulder guards, etc., but the most noticeable changes are the white skirt with blue and gold trim and the long transparent backbows. Compare Sailor Moon◊ and Super Sailor Moon◊. Super Sailor Moon is slightly redesigned in Season 4; the butterfly motif is dropped and Sailor Moon is permanently upgraded to S.S.M. Around the same time Super Sailor Chibi Moon debuted, with the same uniform as Super Sailor Moon except that the blue and gold fuku is pink and gold instead. The other 8 Senshi get Super Modes later on in the story, but the differences between their old and new uniforms are less notable than those of Sailor Moon/Chibi Moon. (i.e. the other 8 Super Senshi still have the same color skirts, etc.)
Talking Is a Free Action: Sailor Moon and other cast members frequently make long speeches upon their appearance into combat. They will never be interrupted... unless the episode is making fun of them for it.
Team Spirit: More than few lessons revolve around the value of the group working as a team. There's also a number of times the team's union can power up Sailor Moon into another form or give her a new power.
Theme Naming: Several places, including most villains being named after gems; creator Naoko Takeuchi's hometown Kofu, Yamanashi is famous for its gem industry. Also, the Inner Senshi's surnames relate to their planets and/or powers:
Mizuno (Ami) = Water / Mercury (Suisei)
Aino (Minako) = The kanji used to represent "ai" refers to love. In Japan, the planet Venus is referred to as Kinsei, which literally translates into "metal star." Venus Love Me Chain and Venus Wink Chain Sword evoke her planet's association with metal.
Tsukino (Usagi) = Moon. "Tsukino Usagi" is a homophone for "Rabbit of the Moon" in Japanese. (While the kanji of her name literally translates into "moon field rabbit," no is also a particle that works much like the English of.) The "rabbit" refers to a Japanese folktale which states that a rabbit lives on the moon pounding mochi.)
Chibi-Usa shares the same name as her mother, Chibi-Usa was coined by Mamoru (and the author's Editor Osa-P in the real world)
Hino (Rei) = Fire / Mars (Kasei). Her full name is a Japanese homophone for spirit of fire, similar to one of her attacks.
Kino (Makoto) = Trees / Jupiter (Mokusei). Her powers are actually dually plant- and electricity-based, inspired by the planet's name in both Japanese and English (along with Greco-Roman myth how the oak tree was sacred to Zeus/Jupiter).
The Outer Senshi (minus one) also have names relating to their roles as Sailors:
Ten'ou (Haruka) means "Sky King" a referance Uranus, the ancient Greek sky deity and planet (Ten'ousei). "Haruka" means "distant".
Kaiou (Michiru) means "Sea King" a referance to Neptune or Poseidon, the Greco-Roman sea god and planet (Kaiousei). "Michiru" means "fill" or "overflow", perhaps relating to her water-based powers.
Meiou (Setsuna) means "Dark King" and refers to the god Pluto, and by extension, the (former) planet Pluto (Meiousei). "Setsunai" can mean "sad" or "lonely", both of which fit the character.
Tomoe (Hotaru) is the Odd Name Out, "Tomoe" being a comma-shaped motif popular in traditional emblems. Of course, The Reveal would lose some of its impact if the Mad Scientist's Sickly Daughter was blatantly named after the one planet that had yet to be represented. "Hotaru" means firefly, which perhaps hints at her true nature. However, her last name does use the same Kanji naming theme using the first character of her planet's name (土) — it just uses a different reading.
A lot of people mistranslate Mizuno Ami as "friend of water", despite the kanji (no) used in most of the last names is "field", and Ami is written with the kanji for second beauty.
Tokyo Is the Center of the Universe: Particularly glaring in the first season: it never occurs to the bad guys to collect human energy somewhere they won't be defeated by teenage girls in mini-skirts. Not so glaring in other seasons, where the bad guys were either based in Tokyo from the start, or were exclusively searching for something they knew to be in the area. (On the other hand, one main issue in the manga was that all the active senshi were drawn to town by the Dark Kingdom. No matter where they go, the Senshi would have been compelled to go there. Also, Sailor V fought bad guys in Greece and China in the manga, and England in the anime.)
Justified, in the manga, the Dark Kingdom says that they have looked all over the world for the Silver Crystal except in Japan.
Not to mention that this trope, in-universe, will indeed be taken to word, with the rise of Crystal Tokyo in the future.
What the Hell, Hero?: Haruka and Michiru think Usagi was too soft on Hotaru toward the end of the third season to effectively rule them in the future. And practically force her to proves her qualifications by kicking their asses. Which she does easily.
In the manga, it was Sailor Moon's turn to chew them out for one count of attempted murder (in connection to their being a Leeroy Jenkins and trying to kill Hotaru).
Write Who You Know: Takeuchi Naoko based Usagi's family off of her own. Several of her friends also provided influence on her characters and the setting is a dead ringer for the neighborhood she grew up in.
You Gotta Have Blue Hair: Chibi-Usa's pink hair, Pluto's and Neptune's green hair, Mercury's blue hair, and several villains with hair colors. Very few background characters have odd hair colors, with one major exception being Usagi's mother, who has purple hair. Others have colors that are fairly odd for Asians but are normal human colors: Minako and Usagi have yellow hair (Perhaps blond) while Haruka has an actual shade of blond or white in some Manga artwork. Princess Serenity also has white hair in manga art.
Chibi-Usa's pink hair is actually commented on by several charcters in the manga, remarking that it's clearly not normal, leading to the fanon speculation that everyone else's hair color is for the viewer only and they actually have rather normal hair colors. Takeuchi actually drew a series of images in which the senshi were all given normal hair colors. You realize quickly how difficult it is to identify some senshi without their signature hair...
Tricky indeed, but not too hard. Their signature hairstyles are largely still intact, and Mercury and Jupiter are still packing their signature earrings. Process of elimination handles it from there.
Half-averted in the live-action adaptation, where the girls only sport their original hairstyles when transformed - in civilian forms, they all have average hair colors and styles (except for Luna in human form). Even Usagi, whose odango are less pronounced and placed at the sides of her head.
In the anime, Queen Beryl offed Jadeite and Zoisite herself for repeated failures and insubordination. Sailor Galaxia killed three of her the four Sailor Anima-mates for this (one of them died on her own). Zirconia dispatched the Amazoness Quartet to remove the Amazon Trio for their failures. Several villains were killed by other villains, but this was usually not for failure or to make a point, but done out of spite, revenge, or power plays.
In the manga, only Sailor Tin Nyanko was explicitly killed by her boss for failing in her duty. Most of the manga' villains actually die at the hands of the Sailor Senshi, but Jadeite was very close to being disposed by Queen Beryl had he survived his third failure.