Seventeen-year-old Rosalyn "Ross" Quest is the highly skilled heir to a world-renowned Bahamian family of thieves. Despite her exceptional talents in lock-picking, security mapping, and using her signature meteor bracelet, she secretly longs for a normal teenage life and applies to a gymnastics camp. When a job on Paradise Island goes wrong and her mother is captured, Ross enters the deadly Thieves' Gambit competition to secure the ransom money. She must learn to balance her family's strict rule of absolute isolation with the practical necessity of trusting her fellow competitors.

Devroe is a charismatic, impeccably dressed English thief competing in the international heist competition. He prefers social engineering over physical stealth, using his charm and observant nature to manipulate targets and disarm rivals. Entering the Gambit to honor his late father, he targets Ross for an early alliance. His flirtatious demeanor and willingness to share his vulnerable history challenge Ross's deeply ingrained suspicion of outsiders.

As the heir to the powerful European-based Boschart thieving dynasty, Noelia faces immense pressure to secure her position and impress her demanding father. She is fiercely competitive, intelligent, and ruthless in her execution of heists. Having shared a childhood ski camp friendship with Ross that ended in mutual suspicion, Noelia approaches the Gambit as an opportunity to assert her family's dominance, though she privately struggles with the expectations placed upon her.

Rhiannon is a glamorous, highly skilled master thief and the demanding matriarch of the Quest family. She rigorously trains her daughter to be her successor, strictly enforcing the family rule to trust no one outside their bloodline. She actively dismisses her daughter's desire for an ordinary life, maintaining tight control over her schedule and operations. During a botched yacht heist on Paradise Island, she is cornered and taken captive, prompting a massive ransom demand.

Jaya is a trainer for the Quest family and a grounded, realistic presence in their Bahamian home. As someone who truly understands her niece's frustrations, she acts as a primary confidante and offers the emotional support that her sister often withholds. She provides practical, sometimes ruthless advice about surviving in the criminal world, urging her niece to find pliable partners to use during the competition.

Mylo is a charming, reckless teenage thief from Las Vegas who refers to himself as a "Jedi thief." Equipped with specialized gadgets like a pen that cuts and welds metal, he brings a gambler's thrill-seeking attitude to his heists. He chases the adrenaline of high-stakes danger to distract himself from his personal anxieties, making him an unpredictable but vital teammate during the competition's group phases.

Kyung-soon is a fashion-conscious competitor from South Korea who initially masks her capabilities behind a love for K-pop and designer clothes. She is a highly competent hacker whose ability to bypass secure databases and clone digital keys proves essential during the team challenges. Her technical expertise allows the thieves to investigate target security details and uncover hidden surveillance files.

Taiyō is a methodical, analytical thief from Japan who approaches the high-stakes contest with cold precision. He rarely displays emotion, treating the competition as a field test to gather data for building his own future thieving syndicate in Asia. His logic-driven nature and meticulous planning make him a dangerous opponent who readily exploits the weaknesses of his rivals.

Adra is a chic, glamorous thief from India who quickly aligns herself with Noelia during the early phases of the competition. Armed with weaponized rings and a confrontational attitude, she enjoys the physical combat aspects of the Gambit and views her fellow contestants with open disdain.

Lucus is an aggressive Australian competitor who relies heavily on intimidation and brute force. He serves as the physical threat for his team, carrying a concealed switchblade and eagerly anticipating violent confrontations with the other teenage thieves.

Yeriel is a quiet, graceful teenage thief from Nicaragua participating in the Gambit. During the first phase at a museum in Cannes, she suffers a gunshot wound from a guard, forcing the other competitors to choose between securing their own victory and pausing to save her life.

The Count, whose real name is Aurélie Dubois, serves as the polished, impersonal face of the organization running the Thieves' Gambit. She enforces the deadly rules with calm control, dispensing sudden penalty games and monitoring the competitors' progress from the shadows.

Nicholi is Noelia's younger brother, entrusted by the Boschart family with a long-term assignment gathering blackmail material. He operates undercover while attending the elite Hauser boarding school in Switzerland, acquiring damaging information on powerful global figures.

Gabriel Raines is a politician traveling aboard a train to Paris. He unwittingly becomes a target for the teenage thieves when the Gambit organizers issue a surprise penalty game demanding the competitors acquire his mobile phone.

Sadia Fazura is a wealthy socialite attending a high-stakes auction in Cairo. Because her personal security detail is relatively weak, the competitors target her as an ideal proxy to manipulate into purchasing a golden Egyptian sarcophagus.

Nala is a lonely Siamese cat living inside a heavily guarded Kenyan mansion. Though she enjoys physical luxury, she lacks affection and actively seeks companionship from intruders, continuously trying to escape the confines of the estate.