Series / The 100

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Survival isn't who you are. It's who you become. note 

"Who we are and who we need to be to survive are two very different things."
Bellamy Blake

The 100 (pronounced "The Hundred") is an American post-apocalyptic drama series airing on The CW. It is based on the novel of the same name by Kass Morgan. The series premiered on March 19, 2014, following Arrow.

Ninety-seven years prior to the start of the series, Earth was devastated by a nuclear war, killing all inhabitants and washing the planet in radiation. The only survivors of the human race were residents of twelve space stations, which were later combined into a single massive station called The Ark.

As the series begins, one hundred juvenile offenders are sent down to Earth on a special mission to determine whether or not it has become safe to inhabit again. If they survive the mission, they will be cleared of their crimes. However, many of the youth have mixed feelings about helping the society that threw them away, despite the fact that said society is deteriorating faster than its highers-up would like the general population to believe. Further complicating matters is the revelation that — despite what the Ark previously believed — the 100 are not alone on Earth.

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Tropes present in this series:

  • Accidental Murder: When their radios do not work, the 100 launch flares in the hopes that the Ark will see them and realize that they are alive. Unfortunately the flares land in a Grounder village and burn it down, which the Grounders take as an act of war.
  • A Child Shall Lead Them:
    • After the 100 are joined by other members from the Ark, they are absorbed back into the official political structure headed by the Chancellor. Clarke, however, retains a position of power due to her history and influence with the Grounders. It culminates in a standoff in season two, where she speaks the line "You might be the Chancellor, but I'm in charge". In season three, her reputation as Wanheda, "The Commander of Death", continues to give her elevated standing with the Grounders and the Ark.
    • Season two introduces the the mysterious figure of "The Commander", who rules over all the Grounders. Though it is initially implied to be the older Gustus, it is actually Lexa, a teenager who has already been in command for years.
  • Action Girl: The Grounders do not appear to have any assigned gender roles, and women are trained as warriors and leaders alongside the men.
    • Anya is the first Grounder leader encountered by the 100, she is a leader of the Woods Clan and is the first recurring antagonist of the series.
    • Indra is the commander of the Woods Clan, who is hostile to the Ark but becomes a valued ally as they work together.
    • Lexa is the Grounder Commander, who heads the Twelve Clans.
    • Octavia is mentored by Indra in the second season, learning Grounder ways and how to fight.
  • Action Survivor: None of the 100 know anything about Earth and very few know anything about combat. Those who survive do so by slowly learning how to fight.
  • Adaptation Expansion: The books focus on little else besides the 100; the show does more worldbuilding by lending focus to the adults on the Ark and the Mountain Men, and goes deeper into Grounder culture.
  • Adaptation Name Change:
    • From "The Colony" in the books to "The Ark" on the show.
    • People who survived the nuclear winter are called "Earthborn" in the books while the show calls them "Grounders."
  • Adapted Out: Glass and her storyline are not present in the series, which focuses on Wells, Clarke, Bellamy (the other 3 POVs) and the rest of the 100. Conversely, a bunch of Canon Foreigners were created. Other characters to be cut from the novels include Thalia, Luke, Lilly, Asher, and Graham.
  • After the End: 97 years after a nuclear war that spanned the globe. The Ark is a conglomeration of twelve space stations that were in orbit around Earth at the time, and to the knowledge its inhabitants they were the only survivors. However, there are large populations of humans still on the planet which have developed their own societies after the destruction.
  • All Crimes Are Equal: On The Ark, all crimes are punishable by death unless you are under eighteen years of age. Juveniles are held in solitary confinement until their eighteenth birthday, whereupon a trial is held to determine if they should be executed or allowed to re-enter Ark society. This is for population control purposes, as there is limited life support on The Ark.
  • Alliterative Name: A recurring theme with Callie Cartwig, Bellamy Blake, Jasper Jordan and Raven Reyes.
  • Almost Dead Guy: Gina has been stabbed by a Grounder who activates a self-destruct in Mount Weather, but manages to tell Raven to get the deactivation code so that she can turn off the self-destruct. Though Raven does get the code, Gina has bled out in the intervening seconds and died before she could deactivate the self-destruct.
  • Always Chaotic Evil: Though the Grounders are revealed to be much more complicated than as first appears, both they and the 100 regard the Reapers as unreachable murderous monsters. The Reapers are ultimately revealed to be Grounders harvested by the Mountain Men, turned feral by way of a Fantastic Drug.
  • Anarchy Is Chaos: The 100 are a mess after Bellamy takes the reins and declares that they can do "whatever [they] want, whenever [they] want." It takes Wells' and Charlotte's deaths and Murphy's exile to make them realize they need laws.
  • And Starring: "With Isaiah Washington And Henry Ian Cusick"
  • Apocalypse How: Caused by a nuclear war. The effect was "Planetary/Societal Collapse" for Earth and "Societal Disruption" for the Ark.
  • Artificial Intelligence: The Stinger for the end of the second season revealed that an AI was waiting for Jaha since he brought her a nuke unwittingly when he landed.
  • Artistic License Biology: The second season introduces the Mountain Men, who are unable to metabolize the radiation outside their mountain home. They break out in instantaneous lesions and bleeding wounds when exposed to radiation, which are treated with blood transfusions from Grounders or members of the Ark. The blood transfusions not only prevent further damage, but heal what has already occurred. They then move on to bone marrow transplants from Ark members to cure their radiation weakness.
  • Artistic License Engineering: In the second season, Jaha descends to the ground using a nuclear missile. We can assume that it wasn't specifically converted into a shuttle because the warhead is still inside, yet it has a braking parachute and enough internal room for Jaha to climb aboard.
  • Ass in Ambassador: In season three, the Ice Nation has become belligerent and intends to break the Grounder Coalition; their ambassador's are condescending and hostile to the other Grounder tribes and the Sky People. One of them gets himself defenestrated for his arrogance, but that has no tempering effect on the others.
  • Badass Boast:
    • Raven is very self-confident when it comes to her engineering skills. When Bellamy points out that the bridge she intends to destroy has survived nuclear war and one hundred years of weather, she is undaunted.
    Raven: It won't survive me.
    • In the second season, despite the resumption of political rule by the Ark survivors, Clarke retains her power from her influence with the Grounders.
    Clarke: You may be the chancellor but I am in charge.
  • Beauty Is Never Tarnished: Averted - When characters get into fights they receive large lacerations, bruises and other damage that cover their faces. They also get muddy, greasy, and generally disgusting over the course of living and fighting in a forest. Whenever anyone gets wounded the effects remain for the next several episodes.
  • Better The Devil You Know: Chancellor Jaha is perfectly willing to accept the Ark's code of laws which require the execution of all criminals over age eighteen, even those who have committed minor crimes. That said, Abigail, whose husband was executed under Jaha's administration because he knew too much, says she prefers having Jaha in power over Kane and even risks being executed herself to keep him alive.
  • Big Brother Instinct: Bellamy and Octavia's relationship in spades. Bellamy's one redeeming character trait before Character Development is his care and protection towards Octavia (and even then, he was overprotective). His protection of Charlotte is also suggested to be due to his big brother instinct.
  • Biological Weapons Solve Everything: The Grounders send Murphy back to the 100 after infecting him with a virus to leave them all feverish and weak when they invade in the morning. It doesn't quite work, but only through quick thinking on the 100's part.
  • Bi the Way: Clarke is initially attracted to Finn, one of the boys sent down with her from the Ark, but begins to grow close to Lexa, the Grounder Commander, during the second season. No characters in the series find it necessary to comment on the gender of either love interest.
  • Blood from Every Orifice: The virus the Grounders send the 100 has people bleeding from the eyes, mouth, and nose.
  • Book Ends: Clarke starts and ends the first season alone, locked in an empty room with a painting of the night sky.
  • Born-Again Immortality: The Grounders note  believe this is what happens to their Commanders: when they die their spirits choose the next Commander and are reborn.
  • Boxed Crook: All 100 of the juveniles sent to Earth. If they succeed in their mission to Earth (read: survive, thus proving the habitability of the planet), then they will be pardoned for their crimes.
  • Brains: Evil; Brawn: Good: While the Grounders are the antagonists throughout much of the series, their conflicts with the Sky People come as much from mutual misunderstandings as innate hostility. Meanwhile, the high-tech Mountain Men are willing to perform horrendous experiments and murder teenagers so that they themselves can go outside.
  • Brainwashed and Crazy: The Reapers, who are Grounders forcibly given a drug to turn them feral.
  • But What About the Astronauts?: The entire surviving human population is descended from the astronauts who were living on space stations at the time of the nuclear war...or so they thought. Turns out Earth is a bit more populated.
  • California Doubling: The series is filmed in Vancouver, despite being set on the east coast of the United States, primarily in Virginia and the territory surrounding Washington, D.C.
  • Cannibalism Superpower: The Grounders believe that if you kill someone you absorb their power. This is the main reason why there is a price on Clarke's head at the start of season three; as Wanheda, the Commander of Death, absorbing her strength would change the balance of power amongst the Grounders.
  • Canon Foreigner: The rest of the 100 that aren't Wells, Clarke, Octavia, and Bellamy were not identified by name in the book, let alone given personalities.
  • The Chains of Commanding: A running theme of the series is that the job of leader isn't an easy one: Sometimes you have to do things that go against everything you stand for in order to protect your people. Jaha had to execute people on The Ark just to ensure Population Control and conserve dwindling resources, which clearly took a toll on him. Kane, a Well-Intentioned Extremist, had to deal with the guilt of knowing that the people he had killed didn't need to die. Clarke, The Medic and an All-Loving Hero, couldn't handle the strain of being forced to kill in defense of The 100 and left Camp Jaha for parts unknown because of it.
  • The Champion: Deconstructing the concept of the Champion is a recurring theme throughout the series, as Champions often perform morally ambiguous or directly-amoral actions for the protection of the one being championed. In each instance, the one being championed resents having the responsibility being placed on them for the actions of the Champion, or opposes the Champion's actions directly. Every Championed pair either learns to leave that dynamic behind, or is destroyed by it.
  • Character Development:
    • Clarke goes from a naive All-Loving Hero into a Pragmatic Hero willing to do morally ambiguous things to survive.
    • Bellamy starts as a selfish anarchist whose one redeeming trait is his care for Octavia, but grows into a dependable leader who genuinely cares about the others.
    • Finn begins the series as a charming, devil-may-care rebel but becomes The Conscience of the group, before descending into obsession in season two.
    • Octavia is impulsive, spontaneous, and rebellious, but matures considerably into someone willing to put her life on the line for those she loves.
    • Kane's initial characterization focuses on his willingness to do whatever pragmatic action was required in order to safeguard the Ark, but he gradually learns that a more caring approach can have even more beneficial results.
    • Jasper is awkward and dorky at the beginning, but is forced to grow up considerably in season two after becoming the de facto leader of the 47 survivors in the Mountain. The events of the second season finale were especially hard on him. The scene where Raven gives him back his goggles (which he'd been without for the entirety of the season due to being in Mount Weather) is supposed to symbolize how much he's changed.
    • Raven's character development focuses on how she starts to depend less on Finn and more on herself.
    • Murphy returns from his exile as a violent sociopath, but throughout season two he learns to appreciate the help of others and skills he can offer them in turn.
  • Cold-Blooded Torture:
    • The 100 torture Lincoln when they are trying to find the cure for a poison. He refuses to break under the direct pain, but gives up the cure when he sees Octavia infect herself in front of him.
    • When the Grounders captured Murphy, they tortured him from information about the 100's camp. He later tells the 100 that he gave up everything he knew.
    • Lexa relates to Clarke a story about the death of her girlfriend in the backstory, who was kidnapped and tortured by a rival clan who thought she knew Lexa's secrets.
  • Cold Equation:
    • With only four months left of life support for the Ark's current population, the option is quickly raised to "reduce" the population to buy time to repair it. it is determined that three hundred people need to be removed in order for the remainder to have sufficient oxygen to survive. The original plan was for there to be an "accident" in crew quarters, but when the general population learned of the danger, three hundred people volunteered so that their families could live.
    • The Ark only has a single dropship ready to return to Earth, and it can only hold 700 people. The Ark's total population is over 2,000; who gets to go? The question is rendered moot when the dropship is stolen after a failed coup d'etat, and crashes during its atmospheric entry.
  • Con Lang: Trigedasleng, the other language spoken by the Grounders, which seems to be at least partially based on English. The creator of the language says that it is derived from English, specifically from codes used by survivors to identify if someone was friend or foe. If you understood the words you were presumably a member of the group; it then developed into a language of its own with distinct rules.
  • Crapsack World: The Ark is barely maintaining long-term life support, to the point where population control is in effect, adult criminals are executed regardless of the severity of the crime, and in times of emergency people are culled to reduce the load on the systems. Earth, while habitable, is a dangerous place even before the 100 discover that it is already inhabited by people who regard them as invaders. Survival — for those who manage to survive — often comes at the cost of great personal sacrifice and/or committing horrible acts against other people when their attempts to survive come into conflict with yours.
  • Curb-Stomp Battle:
    • Bellamy's rescue team vs. Grounders. A group of juveniles up against hardened warriors born and raised in a hostile and lethal forest on the Grounders own territory. The rescue party is slaughtered almost to a man.
    • Octavia tries to go up against a seasoned Grounder warrior in "Survival of the Fittest." The end result is...not pretty. Fortunately for Octavia, her determination and spirit merited her training to improve her skills.
  • A Day in the Limelight: "Spacewalker" focuses on Finn and Raven, showing part of why Raven is so devoted to him.
  • Destination Defenestration: Lexa tosses the Ice Nation ambassador off the high Grounder tower when the Ice Nation belligerence becomes too transparent.
  • Downer Ending: The season 2 finale. Mount Weather releases their Grounder prisoners so Lexa takes her army and goes home, leaving Clarke high and dry. Clarke is forced into an escalating duel of wills with Cage Wallace, which eventually leads her to flood the mountain with radiation and kill all within, including Maya. The remaining Ark crew finally return home but Clarke can't bring herself to join them. In the B-plot, Jaha discovers that the nuclear warhead from the missile he rode to the ground has fallen into the possession of the insane A.I. that started the nuclear war in the first place.
    Clarke: I tried to be the good guy.
    Abby: Maybe there are no good guys.
  • The Dreaded: The "Reapers", a breed of Grounder so terrifying that even Anya and her tribe of hardened warriors don't dare venture into the tunnels that the Reapers call home.
  • Driven to Suicide: Pre-teen Charlotte (the youngest of the young convicts sent to Earth), guilt-ridden over having killed Wells in a misguided attempt to quiet her inner demons and unwilling to be the cause of any more bloodletting, averts Infant Immortality by jumping off a cliff to her death.
  • Dropped After the Pilot: In the pilot, Abigail had a best friend called Callie Cartwig who was an important enough member of the Ark that she could act as liaison between the rulers and the people and speak on the council's behalf, and openly confronted Kane. She isn't even mentioned passed the first episode due to budgetary reasons, and Word Of God is the character was executed offscreen.
  • Duel to the Death: Phase 2 of the Cerberus Program involves two Grounders killing each other for another dose of the Psycho Serum, which they're addicted to. Those that kill the loser go on to become Reapers.
  • Dwindling Party:
    • The 100 don't number a hundred for very long, much to the chagrin of their leaders. They were actually "the 98" within the first twenty minutes of the show. The producers have joked that by the end of the first season, they should be called "The 50". In the first season finale, Bellamy notes that 18 people have died out of the population of 102...and that's before the battle with the Grounders. In the second season, they have the additional threat of the Mountain Men wanting their ability to withstand radiation to contend with. By the second season finale 48 of the original 102 are left according to the staff.
    • The band of followers Jaha takes with him to find the City of Light. By the second season finale's end, only he and Murphy are still alive.
  • Dysfunction Junction:
    • Clarke's mother directly had a hand in her father's death and Clarke herself spending a year in solitary confinement for simply knowing what her dad knew.
    • Bellamy and Octavia's mother kept Octavia hidden under the floor of their quarters for years. When this was found out, she was executed, Octavia was imprisoned, and Bellamy lost his spot on the guard.
    • Raven's situation is not too expounded upon, but it's mentioned that her mother was an alcoholic and neglectful and that it's somehow messed up enough that she considers Finn the only family she has.
    • Murphy had two loving parents until his father got floated stealing medicine for Murphy's illness and his mother spent the rest of her life blaming him.
  • Dystopia: The Ark isn't a great place to live, what with harsh laws and the tight restrictions on resources and population, but it's mostly just a matter of trying to survive on limited resources. It's still not without reason that the kids are happy to be left to their own resources on Earth.
  • Emotions vs. Stoicism: Discussed during Season 2. Lexa believes that Love Is a Weakness and that Clarke should follow her example if she wants to be an effective leader. Clarke tries and comes to the conclusion that closing yourself off to all feelings is pointless.
  • Empathy Doll Shot: Dolls or toys are sometimes found and focused upon in pre-war ruins, calling to mind the children's death. The second season finale has the soccer ball that some of the Mountain Men children were seen playing with - in the scene where they have all died from radiation, it makes a reappearance at the very edge of the screen, hinting at the children's corpses just beyond it.
  • Enemy Mine:
    • Clarke works with Anya to escape Mount Weather in "Reapercussions." Despite the fact that Clarke basically saved Anya's life, Anya knocks her out and plans to take her back to the Grounders because she "can't show [her] face without a prize."
    • Camp Jaha and the Grounders are mistrustful of each other, but are willing to work together to take down Mount Weather because they both have people trapped inside.
    • Queen Nia of the Ice Nation allies herself with Emerson, Last of the Mountain Men in order to go after Clarke and the Coalition.
  • Eternal English: Despite a hundred years of mutual isolation, the Sky People, Grounders and Mountain Men can all understand each other perfectly fine in English, although the Grounders do have their own Con Lang as well.
  • Everything Trying to Kill You: Averted, despite the characters believing it to be the case. Despite talks about how "everything" is toxic on Earth, plants and animals do not seem to be any more or less dangerous than the natural flora and fauna of the real world. By the second season the Sky People have learned how to naturally survive.
  • Everyone Has Standards:
    • Even the strictly controlled dystopia of the Ark is reluctant to kill children, holding them until they are eighteen to receive a trial then.
    • Murphy has shown himself to be a general Jerkass, who is quite comfortable with cold-blooded murder when he's not out being the local bully. But even he seems horrified when Finn wants to attack a village, starts threatening them, and especially when he starts killing them. Murphy even tries to convince him to just leave on a few occasions. Likewise later when Jaha sacrifices their companion to keep him and Murphy un-eaten.
    • The President of Mount Weather, for all that he appears to be somewhat shady and cagey, does refuse to countenance forcing the teenagers in the complex to be experimented on.
  • Exact Time to Failure: In Season 2, one of the Mountain Men is kept alive to deliver a message by foot to Mount Weather. He is given 6 hours of oxygen to make an 8-hour walk.
  • Explain, Explain... Oh, Crap!: Finn and Clarke were talking about how her friend Wells betrayed her.
    Finn: Are you sure Wells told his dad?
    Clarke: He's the only person I told.
    Finn: But is he the only person who knew?
    [Clarke stops to think for a moment. The only other person who knew was... her mother.]
  • Faking the Dead: Removing the wristband monitors makes the wearer appear to be dead as far as the people back on the Ark know. After the landing, Bellamy wants to make it appear that The 100 all died so the Ark won't send anybody else down, leaving them free to live by their own (lack of) rules.
  • Family of Choice: Because of their time on the ground away from the adults in space and the hardships they undertook to survive, the 100 become fiercely protective of each other and consider each other family.
  • Fanservice: The initial episodes had Octavia frequently in revealing (Or no) clothing as she reveled in being free on Earth, but this aspect was dropped from the show before the end of the first season. All characters are dirty, wounded and swathed in armor and makeup as required by their station.
  • Fantastic Racism: The Mountain Men see the Grounders as animals.
  • Fantasy Counterpart Culture: The Grounders are increasingly looking like the First Nations, especially in relation to the would-be colonizers from the Ark.
  • Fantasy Gun Control: The Grounders do not have any technology resembling firearms, not even primitive explosives. Season two reveals that this is enforced by the Mountain Men; they destroy the entire village of any Grounder who so much as touches a gun, so the Grounders live in superstitious dread.
  • Felony Misdemeanor: Due to All Crimes Are Equal, the tiniest misdemeanor is the same under the law as cold-blooded murder. However, although they are punished equally by the law, society hasn't come to view misdemeanors as death-worthy offenses and instead resents the laws, at best accepting them as a brutal necessity.
  • Fire-Forged Friends: During the pilot, five of the main cast, Clarke, Octavia, Jasper, Monty and Finn go off to Mount Weather to get food and supplies. During this hike, Jasper saves Octavia from being killed by a snake and then, after he tries to show off his courage, gets Impaled with Extreme Prejudice. The other four (except Octavia because she's injured from the snake) plus Bellamy go to save him. This results in them all becoming close friends.
  • First Episode Spoiler: The reason the 100 were sent to Earth is because the Ark is dying, a fact those in charge are trying to keep from the general populace. The Earth is also not as empty as they Ark had believed.
  • Five-Man Band: Usually the 100 will split into this.
  • Friend or Idol Decision:
    • There is a possible truce between the Grounders and Camp Jaha in order to deal with Mount Weather. But, to solidify it, the Grounders want Finn to die for killing all of the innocent people at the village. Clarke chooses the alliance.
    • At the climax of season two, Cage offers Lexa a deal: He will let all of the Grounder prisoners be released in return for her abandoning the Sky People. Lexa chooses her duty to her people—even though she's obviously in pain, and official commentary says she had genuinely fallen in love with Clarke.
  • Four Lines, All Waiting: The first part of season 2. By the fifth episode, they've converged.
    • Clarke escaping Mount Weather along with Anya, leaving the rest of the surviving 100 behind. After Clarke makes it back to Camp Jaha, scenes with Jasper, Monty, and Miller fill in this plotline.
    • Bellamy, Murphy, and Finn searching for Clarke and the others.
    • Abby and Kane struggling to lead Camp Jaha.
    • Octavia trying to find Lincoln and the others, coming into conflict with Grounders.
    • Jaha crashlanding on Earth after being left behind in "We Are Grounders pt. 2" and making it back to his people.
  • Future Slang: Averted. Slang doesn't appear to have evolved much at all during the last 97 years. A single exception is the term "floated"; used to refer to spacing, it has come to be a catch-all term for being killed that persists even after returning to Earth.
  • Genocide Dilemma: The end of the second season comes down to a question of whether Clarke will kill the entire population of Mount Weather, including those who aided her friends, or allow the Mountain Men to kill her friends. She and Bellamy ultimately go through with it, killing off the entirety of the Mountain Men population.
  • Gilded Cage: How Clarke sees Mount Weather, contrasting Jasper's view of it: They have great facilities, they are cared for, and the president actually seems like a pretty stand-up guy, except that the 100 are not allowed to leave and Clarke fears that they have an ulterior motive. Ultimately, the Mountain Men begin to kill the Sky People to harvest their blood and bone marrow.
  • Green-Eyed Monster:
    • Raven is very jealous after she risks her life to come down Earth to find Finn, only to find that he has slept with Clarke and continues to prioritise his feelings for her. This isn't helped by people repeatedly drawing attention to it.
    • The trope is downplayed in season two, as Monty is noticeably irritated that the budding romance between Jasper/Maya is driving a wedge between him and Monty.
  • Grey and Gray Morality: Even the best characters have their flaws, and the antagonists have their redeeming qualities. Multiple characters have explicit debates on whether or not their actions are any more justified than their opponents, and where they stop being the heroes of the story.
    Clarke: I tried to be the good guy.
    Abby: Maybe there are no good guys.
  • Hair Contrast Duo: Blonde, idealistic, caring Clarke with, well, pretty much everyone she interacts with at first, especially her more pragmatic mother and the older, moodier Bellamy. After she has made the damning moral compromises at the end of season two, her hair has been artificially darkened at the start of season three.
  • Hereditary Republic: The Wallace family has held the Presidency of Mount Weather for three generations.
  • He Knows Too Much: Clarke's father was executed because he found out that The Ark was running out of life support systems and tried to go public with the information.
  • Hufflepuff House: The Grounder Coalition is made up of 12 Clans, but the only ones that get any development or screen-time are the Woods Clan (The Tree People or Trikru) and the Ice Nation (Azgeda). Of the other 10, the only ones who even have a name are the Boat People.
  • Human Resources: Season two reveals that the Mountain Men have used Grounder blood to treat their weaknesses to radiation, and in season two begin to harvest bone marrow from the Sky People as well.
  • I Cannot Self-Terminate: Clarke punctures Atom's jugular to spare him a more drawn-out death after he's burned so badly by acidic fog that he can barely move and is begging to die.
  • I Did What I Had to Do: Multiple people on the Ark claim they alone are doing what must be done. Kane uses it to justify ordering Abby's execution for breaking a minor law to save Chancellor Jaha, while she says she did what she had to do to save Jaha so Kane would not become Chancellor.
  • The Immune:
    • The Grounders and the Ark-survivors are able to live on the surface because they had adapted over time, with natural selection ensuring that immune grounders passed it on and the Ark-survivors grew up with solar radiation, which is even stronger. The people who live in the underground base didn't, so any exposure to the outside world could kill them.
    • Octavia, Jasper, and Finn are immune to the virus the Grounders send to weaken the camp.
  • Infant Immortality: Averted. Not even kids are safe on the Death World. Preteen Charlotte is Driven to Suicide and young Artigas is shown to be one of the victims of the Grounder massacre. Bellamy is notably conflicted about killing off the innocent kids in Mount Weather, but he and Clarke end up doing it to keep the Sky People safe.
  • Info Dump: The pilot starts with a rather massive one that manages to load the main backstory into a couple of minutes of narration and As You Know conversations.
  • Intergenerational Friendship: Murphy and Jaha on their journey in season 2. They do grow closer, but it's also happening in the middle of Jaha's Sanity Slippage.
  • Involuntary Battle to the Death: The Grounders force this on Jaha and Kane, with the ultimatum that both of them will die if they refuse. They resist for two days, instead discussing how to broker peace. Turns out to have been a Secret Test of Character by Lexa, who had posed as a slave girl in the same cell in order to decide whether their desire for peace was genuine.
  • Ironic Echo:
    • In the second episode: "I thought you said there are no rules."
    • In the third: "I have to slay my demons."
    • "I Am Become Death" has "Bygones." Though spoken by the same person in each case, the context is radically different.
    • In S2-E16, Lincoln injects Cage with the same drug used to turn Lincoln into a Reaper. As Cage dies, Lincoln says "the first dose is the worst." This is the same thing Cage said when he dosed Lincoln.
    • Likewise, just before taking Jasper away to harvest, Doctor Tsing says to the teens "I want you to know, you're very special to us." Guess what Jasper says shortly afterwards, when she's dying of radiation exposure?
  • Jerkass Has a Point: In "Murphy's Law", Murphy is brutally beaten and nearly hanged for a murder he didn't commit because Clarke made the accusation loudly and publicly without considering the consequences. Afterwards, when Murphy wants to execute the actual murderer, even Clarke realizes that she should have handled the entire situation more quietly from the beginning.
  • Just a Kid: The adults of Camp Jaha repeatedly dismiss Clarke, Bellamy, Finn, Raven, etc. and insist on enforcing their way of doing things, despite the 100 knowing more about Earth by the time they arrived, because they're "just kids".
  • Just for Pun: The survivors of the Ark rename their settlement on Earth as "Arkadia"
  • Kangaroo Court: The Commander of the Grounders allows them to put Finn on trial, but expects they will condemn him to death because of his crime.
  • Karmic Death: Finale of season two. Cage dies from the very drug he used to turn Grounders into Reapers, and the very syringe he was about to inject Lincoln with. The event even comes with an Ironic Echo.
  • Last of His Kind: As of season 3, Emerson, Last of the Mountain Men, is the Sole Survivor of the people of Mount Weather.
  • Layman's Terms: Abby pulls one of these with Raven in "Fog of War" while they listen to jammed radio frequencies.
    Abby: That sounds clear to you?
    Raven: Will be once I crack the encryption.
    Abby: English, Raven. What does that mean?
  • Light Is Not Good: Our first glimpse of Mount Weather is in an all-white room, with Clarke in an all-white outfit. Everything is cleaner and more orderly than the Grounders, and the people are more polite. They are, however, the driving villain of the second season, whom even the Grounders fear and hate.
  • Magical Defibrillator: Abby uses a shock stick to restart Lincoln's heart.
  • Mauve Shirt: Initially the series focuses on the main cast trying to lead the 100, so some minor delinquents are given a bit of personality before their inevitable doom. Lampshaded by Myles, who comments that he and the main cast don't really hang out much. He's offed later in the same episode.
  • Meaningful Echo:
    • In "The Calm", Jaha informs Kane that the actions he took to help the survivors of the Exodus ship disaster were against the law. Kane responds that a wise man once told him that you have to know when not to follow the law, a Call Back to Jaha and Kane's conversation in the Pilot.
    • The phrase "May we meet again" is used frequently by the Arkers, in both temporary-but-uncertain goodbyes and as last rites to the dead. Lexa repeats the Ark phrase to Clarke in "Blood Must Have Blood part 1" echoing Clarke's use of the Grounder rites over Finn in "Remember Me".
    • From the season two finale, "Blood Must Have Blood part 2":
      • Clarke tells Bellamy that "[he] did good" with the 100 in "We Are Grounders." Kane tells him this again after the Arkers are freed.
      • The phrase "good guys" — in an earlier episode, Abby chides Clarke by telling to remember that they're the good guys. After Clarke's actions in this episode, she tells her mother that she tried, and Abby tells her, "Maybe there are no good guys."
      • Bellamy tells Clarke that if she wants forgiveness for irradiating Mount Weather and killing everyone inside, he's willing to forgive her — a direct parallel to their conversation in "Day Trip" where Clarke forgives him for indirectly causing the Culling.
      • When Clarke refuses, she says "I bear it, so they don't have to", the same thing President Wallace said to her earlier in the episode.
  • Meaningful Name:
    • The "Ark". As in Noah's Ark.
    • One of the episodes is titled "Murphy's Law".
    • In Classical Mythology, Cerberus was guard dog to the Underworld. The "Cerberus Project" involves creating Reapers out of strong Grounders so that the Grounders will fear Mount Weather.
    • The episode "Day Trip". Aside from two characters going on a journey, it also features everyone getting high.
  • Medical Horror: The terror of the final episodes from season two comes from the Mountain Men harvesting bone marrow from the 100, cutting them apart and draining them dry.
  • Mercy Kill: Clarke kills kills Finn to spare him from a slow death by torture; this angers both the Grounders (Who wanted to see him suffer) and Raven (Who wanted to save him).
  • Mood Whiplash: When Bellamy, Octavia, and two guards are scoping out the old parking garage, the guard Scott finds a wind-up music box. It plays "Carol Of The Bells", and the two guards smile and enjoy the toy when they are set upon by two Reapers. The music keeps eerily playing as Bellamy and Octavia discover the Reapers finishing the job.
  • Moral Myopia: Discussed and debated when Finn massacres a Grounder village in his search for Clarke. Many attempts are made to justify his actions as because he "didn't know" and "meant well", but these excuses fall flat each time compared to the number of the dead. Ultimately, he surrenders to Grounder justice because is no justification for his actions, and no amount of Us vs. Them thinking can create one.
  • Mushroom Samba: In "Day Trip" nearly everyone eats these nuts with hallucinogenic properties and starts tripping out.
  • Mutants: Present thanks to the extreme radiation post-nuclear fallout altering the genetic structure of some organisms. Their existence is established in the pilot, where the characters meet a deer with two heads. Among humans, mutants are ostracized and looked down upon.
  • The Mutiny: Diana Sidney takes over the exodus ship and sabotages the Ark after trying to kill the council.
  • The Needs of the Many: A recurring conflict — is sacrificing a few people for the greater good of everyone else the right way to go about it?
    • Kane thinks so, and gives the go-signal for what comes to be known as "The Culling" — 320 people killed to buy more time. He later realizes he was very wrong about this.
    • Jaha initially seemed reluctant to believe so, but states as much in "Survival of the Fittest."
    • The reason Tsing is so willing to perform unethical experiments is that continued research will help the Mountain Men return to their proper home.
    • Clarke is adamant about protecting everybody and thus doesn't want to hand over Finn to the Grounders and pushes for the rescue of the 47 in Mount Weather despite the costs.
  • Nice Job Breaking It, Hero:
    • Experimenting with the wristbands made every one of them short out.
    • Bellamy tells Charlotte she needs to slay her demons when she's awake in order to stop her nightmares. Later, she sees Clarke perform a Mercy Kill by stabbing the carotid artery. She murders Wells using the same technique she saw Clarke use, and says it's to slay her demons, given that Wells reminds her of his father, who killed both of her parents.
    • Bellamy calls Clarke out for not keeping her mouth shut about the knowledge of Wells' killer. This ultimately led to Charlotte's suicide.
    • Several of the actions of the teenagers on the ground exacerbate the conflict between them and the Grounders, often on the basis of incomplete or wrong information. Most egregious is Finn failing to stop and consider any alternatives once he has his mind made up that the Grounders have kidnapped Clarke, even amid mounting evidence that they haven't.
  • No One Gets Left Behind: Clarke insists on going back for Jasper once they realize he's alive. Finn rightly points out that they're likely to lose more people saving him, but decides to help when she won't be dissuaded.
  • No Periods, Period: It's pretty fortunate that none of the female members of the 100 seem to experience menstrual cycles while stranded on the ground with no supplies.
  • The Notable Numeral: The 100. It's supposed to be the number of dropped criminals, but Bellamy makes the drop as well, Raven follows soon after, and there aren't a hundred of them anymore.
  • Not So Different:
    • When the 100 learn that the Grounders are coming at them with an all-out attack, Bellamy motivates them by saying that they are Grounders as well: They have learned to fight and survive on the ground. During the battle itself, however, Clarke has to step forward and say that they are not Grounders: She does not want them to descend to savagery in the name of self-defense.
    • When Abby and Kane are trapped under rubble for most of "Resurrection" following Mount Weather's missile attack in the previous episode, they gradually realise that the tough choice Clarke had to make was like the life-or-death choices they had to make on the Ark. She knew the attack was coming and could have warned them, but if she had then Mount Weather would have figured out they had someone (Bellamy) inside who was working for them. She sacrificed a small number of lives for the greater victory.
  • Not So Similar: After Bellamy motivates the 100 in the face of a Grounder attack by explaining that after learning to fight and survive they are Grounders as well, Clarke steps forward and says that they are not Grounders. She does not want them to descend to savagery in the name of self-defense.
  • Nuclear Nasty: One of the threats of a post-nuclear-apocalypse Earth. The first animal seen is a beautiful buck grazing in the forest-and then it turns and we see it has part of a second head growing out of its first. Mutant humans are also present, often with physical deformations such as extreme syndactyly or a deformed mouth.
  • Oh Crap!:
    Clarke: We're not alone.
  • Open Secret: Maya states everyone in Mount Weather knew that the Grounders were being harvested for the sake of their blood. Only the Ark kids didn't.
  • Only Child Syndrome: Bellamy and Octavia are the only siblings seen, and their being siblings is given special weight considering no one on the Ark is allowed to have more than one kid.
  • Only One Name: All the grounders; surnames don't seem to exist among them anymore.
  • Only the Knowledgable May Pass: According to supplemental material, the Grounder Con Lang started as a series of code-words used after the initial nuclear war to distinguish who was or was not a member of their particular group. Over the following century it developed into a fully developed language which the Grounders use alongside English.
  • Peace Conference: Finn tries to organize one between the Grounders and The 100 to prevent violence from escalating once people from the Ark arrive. It failed as both sides brought weapons and Jasper shot prematurely, putting them at war.
  • Plot Armor:
    • In the S1 finale when it's decided the entire Ark would be sent down to the ground, but it was likely only one section of the station would survive. Naturally, it's the only section with named characters.
    • The Mount Weather missile attack doesn't manage to kill any of the named characters.
    • Jaha's band of followers dwindles over the course of Season 2, leaving just him and the other major character in it, Murphy, alive.
  • Population Control: By the Ark's laws, people are only allowed to have one child, the medical resources allowed for saving a single life are strictly limited, and even minor criminals over eighteen are executed instead of imprisoned to conserve resources. Being an illegal child is just as illegal as having one. If the population is still too high to be sustained, then even innocent people can be executed.
  • The Promised Land: The City of Light, a supposed utopia for all outcasts. No one is really sure if it even exists, and the road towards it is dangerous.
  • Promoted to Love Interest:
    • Inverted. In the books, Wells and Clarke were in a relationship prior to his betrayal of her parents; in the show Wells clearly likes her but is offed before anything can come of it.
    • Inverted with Bellamy and Clarke, who get together fairly quickly in the books but show no explicit romantic interest in each other in the show despite clearly sharing a very strong bond.
  • Psycho Serum: The Mountain Men turn strong Grounders into the psychotic, murderous Reapers by injecting them with such a drug. They become so addicted to it that they're willing to kill others in order for another dosage.
  • Punny Name: Some of the episode titles. 'Inclement Weather' and 'Day Trip' stand out.
  • "The Reason You Suck" Speech: President Wallace, the former leader of the Mountain Men, gives one of these to his son (Who has taken over Mount Weather and kept his dad confined):
    You've killed us. One week in office, and you've managed to turn neighbor against neighbor, you've made the outsiders hate us more than they already did, you lost our outer defenses, and now a door that hasn't been breached in 97 years is going to fall, and an army of savages is going to flood these halls, killing every last one of us. While it doesn't happen quite that way, the ex-President turns out to be right.
  • Reasonable Authority Figure: Jaha and Kane for the Ark Survivors, and the president for the Mountain Men.
  • Recycled In Space: The show starts as Lord of the Flies AFTER THE END! AND COED! Though it quickly moves away from this premise.
  • Red Baron: As a consequence of the events of season 2, the Grounders take to calling Clarke "Wanheda", which means "The Commander of Death". Another epithet that she gains is "Mountain Slayer".
  • Redemption Rejection: When Murphy returned from his exile, he seemed to be on the path of redeeming his character, with some even accepting him back, but then he decides to go on a revenge killing spree instead.
  • Related in the Adaptation: Inverted. In the books, Wells is revealed to be half-brother to Bellamy and Octavia, but this is unmentioned and unexplored in the series.
  • Remember the New Guy: Season three introduces a few new characters in the time skip, whom the core cast are already familiar with as friends or family from back on the Ark.
  • The Remnant: The Mountain Men have been revealed as one for the U.S. Government/Military, based out of Mount Weather.
  • Revenge Before Reason: After Murphy regains the trust of the 100, he ruins it all by going on a revenge spree against the people who wronged him. He convinced himself that he would become the leader after killing Bellamy; his plan goes less than spectacularly.
  • Rousseau Was Right: One of the themes of the show is that many of the "villains" are basically good people stuck in wretched situations and forced to make tough decisions. Listing them:
    • Bellamy shot Jaha so he could come to Earth and look after his sister Octavia, and while he does put innocent lives at risk in an effort to save himself he also looks out for The 100 and tries to keep them alive.
    • Jaha has had a lot of people executed and he risked The 100's lives sending them to Earth, but it was all in the name of ensuring humanity's survival. Also, he's a Reasonable Authority Figure who tries to avoid unnecessary killing.
    • Kane plays a big role in the execution of 320 innocent Ark residents, but he's a Well-Intentioned Extremist trying to keep the human race alive. The realization that the aforementioned execution was unnecessary is a huge My God, What Have I Done? moment for him.
    • The Grounders attacked and killed members of The 100, but it was because they believed that The 100 were invaders, a belief that was "confirmed" in their minds when the flares that The 100 used to signal The Ark came back to the surface and burned down a Grounder village.
  • Scenery Porn: Earth looks pretty damn good for a planet that was devastated by nuclear war, and the series isn't shy about showing off the awesome scenery.
  • Screw the Rules, I'm Doing What's Right: To do so risks becoming a Heroic Sacrifice under the Ark's laws, but a near-certain death sentence doesn't stop Abby from using as much blood as necessary to save Chancellor Jaha's life. Chancellor Jaha then pardons her even though she's technically guilty. Jaha later tells Kane that knowing when not to follow the law is an important part of being Chancellor.
  • Sex for Services: Seems to be a common (though illegal) way to trade for favors with what limited resources they have on the Ark.
    • Bellamy's mother did this so she knew when to hide Octavia, as well as to secure Bellamy a spot on the Guard.
    • Suggested of Raven when she needs a part to complete an illegal space lifeboat.
    Nygel: I owe a favor to the chief of electrical, and he's got a thing for tough, pretty girls like you.
  • Sex for Solace:
    • After being confronted with Clarke and Finn's relationship, Raven sleeps with Bellamy to take her mind off Finn and Clarke being out together.
    • In the beginning of season three, Clarke sleeps with Niylah as part of her ongoing efforts to cope with her guilt and despair over the end of season two.
  • Shoot the Hostage: Near the end of the second season, Lincoln is held hostage by a Mountain Men sniper. It's a sign of how far Clarke's gone from her All-Loving Hero beginnings that she simply shoots at the sniper's center mass through Lincoln's shoulder. Lincoln just congratulates her on her good aim and goes to get patched up.
  • Shout-Out:
    • In the season finale, one of the 100s shout "Game over, man!"
    • Ricky Whittle's character was only known as Grounder until he revealed his name to be Lincoln, which so happened to be the name of the character he played on an episode of NCIS in 2013.
  • Shrouded in Myth: A mere three months after the final battle at Mount Weather is all it takes to turn Clarke into a fearsome boogeyman among the Grounder tribes, known as "the Commander of Death".
  • Sins of Our Fathers: Wells catches a lot of flak because people hate his father for enforcing the Ark's draconian laws. It gets him killed in the third episode.
  • Six Student Clique: Clarke (Head), Bellamy and Miller (Muscle), Jasper and Monty (Quirk), Finn and Harper (Pretty One), Raven and Wells (Smart One), and Octavia and Murphy (Wild One).
  • Sliding Scale of Idealism Versus Cynicism: The series proper is started with the discovery that the Ark's life support is failing, and a large number of its people need to be removed from the population in order to extend their existing air for long enough to repair the system. The Council believes that the population cannot be told of this information since it would lead to panic and unrest, while some of its members believe that the people deserve to know regardless. The Council's original plan was to have an "accident" to buy themselves the necessary time, but when the population does learn of this news, instead of rioting enough people volunteer to be culled in order to ensure the survival of their loved ones.
  • Spiteful Spit: When Clarke and Lexa come face-to-face for the first time in the third season, Clarke spits at Lexa and has to be dragged out of the room ranting threats. Lexa is visibly hurt, as she had hoped for a better reunion.
  • Sting: The tension of most dramatic revelations in the series are underscored by the Inception-style BWAAAAA horn.
  • Stupid Sacrifice: The idea of "culling" three hundred people from the Ark's population is proposed because they believe that the Earth is uninhabitable and they have no other options given the breakdown in the Ark's life support. As the 100 and audience learns at the start of the first episode, the Earth is habitable, and if the Ark had that information there would be no need for the culling at all.
  • Super Breeding Program: The original plan that Mount Weather had for the 49 kids were to insert them into the gene pool.
  • Take a Third Option: Given the deciding vote on whether to "cull" 300 innocent citizens to buy time to save the Ark, Chancellor Jaha chooses to abstain so the resulting tie will force a revote in ten days, giving Abby until then to prove the Earth is habitable or they will have to kill them.
  • Take Back Your Gift: Raven returns the pendant Finn made for her when she finds out that he is in love with Clarke.
  • Take Care of the Kids: Abby asks her friend Callie to watch over Clarke for her when she thinks she's about to be executed.
  • Taking the Heat: Finn took the blame for Raven's illegal spacewalk, because he (as a juvenile) would only be imprisoned while Raven (as an adult) would have been floated.
  • Teens Are Monsters: Too much freedom leads to the kids going a little wild. Then they found themselves against the Grounders.
  • Teenage Wasteland: And how! The 100 consist of a hundred teenage juvenile offenders sent down to Earth's surface with absolutely no adult supervision. There was supposed to be a guard, but he was replaced by Bellamy, who is only a few years older. It takes them less than ten minutes to start taking off the wristbands that are monitoring their vital signs and less than a day to declare that their new motto is "Whatever the hell we want, whenever the hell we want." This doesn't last all that long, though — they are forced to get more organized and disciplined as the harsh realities of survival make themselves known.
  • Teeth-Clenched Teamwork:
    • In the early episodes, any collaboration with Clarke and Bellamy. They outright disliked each other then, but were willing to put the rest of the 100 above that. Later, it grows into genuine teamwork.
    • The alliance between the Grounders and the survivors of the Ark. There's rampant mistrust on both sides, but both want to take down the Mountain Men.
    • A constant component of any pairing when someone has to work with Murphy.
  • The Ark: The last bastion for the survivors of the nuclear winter. At least that's what they thought.
  • Theme Naming:
    • Several of the teenagers are named after famous science fiction writers:
    • Grounders have historically themed names.
      • Lincoln's village was built around the Lincoln memorial.
      • Lexa is a name derived from Alexander.
      • Gustus is also a derivative of Augustus.
      • Octavia's eligibility for both the historical and sci-fi name themes might be a nod to her dabbling in both cultures.
  • Third Line, Some Waiting: The back half of season two alternates between the Mount Weather crew and the rest of the Sky People trying to find a way to save them, but adds Jaha and Murphy's quest for the City of Light to the mix. It's geographically removed (as it's them trekking across unfamiliar terrain) and has little in common with the other two plots...until the season two stinger.
  • This Is for Emphasis, Bitch!:
    Octavia: "We're back, bitches!"
  • Thrown Out the Airlock: "Floating," the preferred form of execution, consists of putting a person into an airlock and ejecting them from the outer door.
  • Time Skip: Season 3 starts precisely 84 days after the events of the season 2 finale.
  • Title by Number: Though they are also referred to as "The 100" in-story.
  • Title Drop: 'The 100' is mentioned on a regular basis. Some of the episode titles too, e.g. 'We Are Grounders' is part of Bellamy's speech in said episode.
  • Too Dumb to Live: Let's just say it's easy to see why Jaha considers most of the Hundred expendable. Frequently Clarke or Wells pointing out what they need to do merits nothing but contempt from the rest of the Hundred.
  • Torture Always Works: Averted twice, the series seems to stick with the real-life conclusion that torture is an ineffective means of information extraction.
    • Lincoln did not reveal the poison antidote when the 100 were torturing him, it was only when Octavia poisoned herself that he gave the information to save her life.
    • Finn tortures a Grounder for Clarke's whereabouts, and the Grounder gives them a trail leading to a Grounder village. He had had absolutely no knowledge of Clarke at all, and had sent them to the village because he had a personal grudge against its inhabitants and hoped Finn would serve as his revenge.
  • Trash the Set: The Season one finale sees both regular sets utterly destroyed: The Ark is brought down, and the Hundred's camp is thoroughly incinerated.
  • Tragic Monster: The cannibalistic and savage Reapers turn out to be a whole tribe of these. Season two reveals that they are former Grounder captives, who due to being physically fit were turned into Warrior\Slaves by Mount Weather experiments to be used as both weapons, hunters and gatherers against their will.
  • Troubled, but Cute: Just about every teenage male shown-it comes with the territory of being a juvenile offender in a dystopian future.
  • Two Lines, No Waiting: The first season alternates between the 100 trying to survive on the ground and the adults on the Ark trying to survive in space.
  • Underground City: The Mountain Men live in a military base underneath a mountain converted to something of this sort.
  • Unkempt Beauty: Pretty much everyone on the show since they're mainly in survival mode.
  • Weakened by the Light: The outside world in general but especially sunlight is a death sentence for the Mountain Men since they've lost their ability to metabolize radiation after a hundred years of living underground.
  • We Have Ways of Making You Talk: Said by Bellamy when they needed the antidote from the Grounder. The only one he gives it up to is Octavia, when she takes the poison herself.
  • Wham Episode:
    • "Unity Day" ended with the Exodus ship being hijacked by Diana and crashing into the ground before exploding. Clarke thought that her mother was aboard, and its premature launch has damaged the rest of the Ark so that it will no longer continue to support life. On the ground, the hoped-for peace with Grounders falls apart and war is outright declared.
    • "We Are Grounders" The Ark falls down on Earth, the Hundred destroy their own camp to repel a Grounder attack, Mount Weather has been operational all along, and they kidnapped (at least) Clarke and Monty.
    • "Inclement Weather" Octavia tries to get Lincoln back but Reapers capture him as well as the leader of the Grounder camp, Jaha has a Helpful Hallucination of his son that helps him get back to Earth, and Clarke discovers Anya and other Grounders were captured and then being drained of their blood.
    • "Human Trials" Finn fires on a the civilians of a Grounder village, the Mount Weather lead scientist wants to use the 47 for experimentation, starting with Jasper, the Head of Security drugged Lincoln so much that he was willing to kill for another dose to use as a soldier, and war looks inevitable.
    • "Fog of War" Jasper and Monty learned about the secret of the Grounders being harvested by Maya, we learn that the Lincoln was with a combination of torture, experimentation and brain altering drugs. Was turned into a Reaper, Mount Weather jams the radio signals of the Ark Survivors and unleashed the Acid Fog, and the commander of the Grounders sends Jaha back to them to send a message to leave or die in two days.
    • "Long Into An Abyss" After seeing Abigail save Lincoln from being a Reaper, the Grounders' commander agrees to grant Clarke a truce between their people. There's just this one thing she wants in return... Finn to be executed for killing innocent Grounders.
    • "Spacewalker" Finn ultimately surrenders and it forces Clarke to Mercy Kill him.
    • "Blood Must Have Blood": The main cast all make it, but Lexa betrays the Sky People, ultimately forcing Clarke and Bellamy to irradiate Mount Weather and kill off its population. Jaha and Murphy make it to the "promised land" — only to stumble upon the AI that ended the world the first time.
    • "Ye Who Enter Here": Just when it looks like the alliance conference will go off with a boost for Lexa's prestige, an Ice Nation mole sneaks into Mount Weather and successfully engages a self-destruct sequence, provoking a state of war between the Ice Nation and the Tree People (and by extension, Arkadia, since Lexa had just formally extended an alliance, which Kane accepted). On top of that, there is a very disquieting reveal that one Mountain Man managed to survive - Emerson.
  • What the Hell, Hero?:
    • When Clarke meets with the leader of the Grounders to try and arrange a peace treaty, the Grounder rightly points out that some of the 100's actions could be construed as acts of war (such as capturing and torturing Lincoln). We also learn that the flares used to signal the Ark burned down a Grounder encampment.
    • Clarke and Bellamy deliver a joint one to Abigail for abandoning Finn and Murphy after they went out to rescue Clarke and killing off Anya, the only Grounder willing to work for peace between the two sides.
    • Raven to Clarke after Finn is mercy-killed. This is mostly due to Raven's grief, as she later realises there was no other way.
    • Jasper to Monty after Monty carries out Clarke and Bellamy's order to irradiate Mount Weather. Although Monty didn't have a choice, Jasper had to watch his love interest (and many other people) succumb to the radiation in a gruesome fashion.
  • World of Snark: On a planet populated entirely by teenagers, this is pretty much a given.
  • Worst Aid: The show flip-flops on this. There are episodes where attention is drawn to the correct treatment of various injuries (e.g. leaving a knife in the wound until proper care is available) since Abigail is The Medic and Clarke studied under. In other episodes, they happily transfuse blood of unknown donors and recipients, push arrows through wounds and so on.