For 10-year-old Phiona Mutesi (Madina Nalwanga) and her family, life in the impoverished Katwe slum in Kampala, Uganda, is a constant struggle. Her mother, Harriet (Lupita Nyong'o) , is determined to provide for her family. She works tirelessly, selling vegetables at the market to ensure her children have food to eat and a roof over their heads. When Phiona meets Robert Katende (David Oyelowo) , a former soccer player turned missionary who teaches the village children to play chess, she becomes captivated by the game. Chess requires a high degree of concentration, strategic thinking, and a willingness to take risks—all skills that are essential for daily life. Katende hopes to empower the young people through the game. Phiona is impressed by the intelligence and sharpness the game demands, and it immediately becomes clear that she has a talent for it. When Katende recognizes Phiona's gift for chess and the fighting spirit she inherited from her mother, he becomes her mentor. Harriet, however, is skeptical of the whole thing. She wants to spare her daughter from disappointment. As Phiona succeeds in smaller chess competitions, Katende also teaches her to read and write. Phiona quickly improves at the game and moves on to more challenging tournaments, but she distances herself from her family to focus on her own life. Ultimately, her mother realizes that Phiona has a real chance to achieve something great. She teams up with Katende to help her daughter use her extraordinary gift to escape a life of poverty and save her family.