The 100

Ninety-seven years ago, nuclear Armageddon decimated planet Earth, destroying civilization. The only survivors were the 400 inhabitants of 12 international space stations that were in orbit at the time. Three generations have been born in space, the survivors now number over 2,659,[6] and resources are running out on their dying "Ark" ─ the 12 stations now linked together and repurposed to keep the survivors alive. Draconian measures including capital punishment and population control are the order of the day, as the leaders of the Ark take ruthless steps to ensure their future, including secretly exiling a group of 100 juvenile prisoners to the Earth's surface to test whether it's habitable. For the first time in nearly a century, humans have returned to planet Earth. Among the 100 exiles are Clarke, the bright teenage daughter of the Ark's chief medical officer; Wells, the son of the Ark's Chancellor; Finn, a daredevil who went on an illegal spacewalk; best friends Jasper and Monty and last but not least, maternal half-siblings Bellamy and Octavia, who had to break multiple rules due to Octavia being an illegal second child. Technologically blind to what's happening on the planet below them, the Ark's leaders — Clarke's widowed mother, Abby; the Chancellor, Jaha; and his shadowy second in command, Kane — are faced with difficult decisions about life, death and the continued existence of the human race. For the 100 young people on Earth, however, the alien planet they've never known is a mysterious realm that can be magical one moment and lethal the next. With the survival of the human race entirely in their hands, the 100 must find a way to transcend their differences, unite and forge a new path on a wildly changed Earth that's primitive, intense and teeming with the unknown.

Delinquents: Clarke Griffin – A former medical apprentice of her mother, she was charged with treason for trying to expose the dwindling oxygen supply. Works as a doctor for the kids in camp, Well's ex-best friend, and is recognized as their leader who thinks with her head and will do anything to protect her people. Bellamy Blake† – Octavia's older brother who smuggled himself onto the dropship to protect his sister Octavia by shooting Chancellor Jaha. He became the de-facto leader for the delinquents until he eventually decided to share the job with Clarke, known as the one who thinks with his heart. Octavia Blake – Bellamy's 17-year-old maternal half-sister who grew up hiding under the floor until she was arrested for being born illegally. She starts to identify with grounder culture while on the Earth since she felt rejected by the people on the Ark. Octavia served as one of the main antagonists of Season Five through her obsessive desire to go to war with the Eligius prisoners for the last valley on Earth, but in Season Six, she later becomes a good person to seek redemption. Wells Jaha† – The son of the Chancellor and Clarke's ex-best friend. He intentionally got arrested to be sent to Earth with Clarke by damaging the last tree. Finn Collins† – Raven's boyfriend who was arrested for wasting 2 months worth of oxygen on a spacewalk. Finn became the primary tracker for the delinquents and Raven breaks up with him after realizing he fell in love with Clarke. Jasper Jordan† – Monty's best friend who was arrested with him for stealing medical supplies to grow pot. Jasper became a gunner and the primary chemist for the delinquents. Monty Green† – Jasper's best friend who was arrested with him for stealing medical supplies to grow pot. Monty became the primary engineer and agriculturist for the delinquents. Raven Reyes – Finn's girlfriend who works with Abby on the Ark to get to the Earth and later Clarke on the ground to help them survive, despite finding out Clarke slept with Finn. Raven became the primary mechanic for the delinquents. John Murphy – A delinquent who got arrested for setting fire to his father's arresting officer's bunk. Initially bullied other delinquents until he was banished and later turned traitor for the Grounders, serving as the tertiary antagonist of Season One. Murphy later evolves into a scheming survivalist that tries to help his friends.

Ark Council: Dr. Abigail Griffin† – The Ark Council's chief medical advisor, and Clarke's mother. Abby is an idealist who acts as a moral compass for most of the survivors including her daughter, but tends to be overprotective over Clarke. Marcus Kane – A member of the Ark Council, who initially was more pragmatic and ruthless in his approach to survival. After several tragedies occur on the Ark, Kane softens into a more compassionate and well-respected leader. Thelonious Jaha – The Chancellor of the Ark and Wells' father. He was shot right before the delinquents' dropship launched but managed to survive and continues to do what he thinks is best for his people. Callie Cartwig – An officer aboard the Ark with close relationships with Kane and Abby before she was floated for an unknown crime. Grounders:

Lincoln – The first grounder the delinquents come into contact with from Trikru. Lincoln does his best to help them and forms a relationship with Octavia. Roan† – The prince of Azgeda who returns from exile and is made king and his mother's death. Unlike most grounders under his command however, he only seeks to rule and protect his people, not start wars with other clans. Echo – An Azgeda spy rescued from Mount Weather who initially plots against Arkadia, serving as a recurring antagonist in Seasons Three through Four. After being banished by Roan and traveling to space, Echo comes to trust her new friends and becomes Bellamy's girlfriend. Book 2 Additions:

Jordan Green – Monty and Harper's son, who wakes everyone up from cryosleep so they can explore a new world that is inhabitable. Clarke and Bellamy are entrusted to take care of Jordan, who is naive and socially awkward having spent most his life on a ship. Dr. Gabriel Santiago† – The leader of the Children of Gabriel and initially opposes the Primes while masquerading as a man named Xavier. He later becomes an ally of Clarke's group in trying to take down the Primes and deciphering the Temporal Anomaly. Hope Diyoza - Charmaine's daughter from Planet Skyring who comes back to ask for help in saving her mother from Anders, the leader of the Disciples. Hope injects Octavia with a locator tag and her body disappears into the anomaly. Sheidheda – The Dark Commander who is known as the most brutal and vicious Commander in the history of the Grounders. Although dead, he served as the secondary antagonist of Season Six as he fights for control of Madi's mind through the Flame. In Season Seven, he serves as one of the main antagonists.