Madina Nalwanga, left, and Lupita Nyong'o in Queen of Katwe (Toronto International Film Festival).

That Walt Disney Pictures and ESPN Films have produced a reportedly $15 million movie about a Ugandan teenage girl turned chess champion is one reason Queen of Katwe stands out from the crowd. The atypical East African setting distinguishes this real-life underdog tale, and more importantly, the film isn’t a compromised adaptation of Tim Crothers’s acclaimed 2012 nonfiction title The Queen of Katwe: One Girl’s Triumphant Path To Becoming a Chess Champion. Instead, it’s quietly triumphant, told modestly and straightforwardly. As described by Crothers, Phiona Mutesi (played here by newcomer Madina Nalwanga) is a role model who has no example of her own to follow. She lives in the largest slum of Kampala, Katwe, which is described by Crothers as “one of the worst places on earth.” The book goes on to say, “There is no sanitation service. The flies are everywhere. The stench is appalling.” The film, rather than sensationalize aspects of the shanty town, depicts the township matter-of-factly, with viewers gaining a sense of the environment: the crowded cheek-by-jowl mud and brick dwellings, the congested dirt roads, the lack of electricity and running water—Phiona has to walk several kilometers each day for fresh water. Though certain colors pop out—oranges, yellows, and deep reds—through the cinematography that captures life in the equatorial light, it refrains from turning the landscape into an exotic other world. A girl roughly 10 years old (her exact birthday is unknown), Phiona is supposed to be helping her mother sell maize at market to help feed the family of five; her father died from AIDS when she was an infant. Yet one day out of curiosity, she follows a brother to a wooden one-room church where he and more than a dozen kids gather around chessboards (some homemade) in a mission run by Robert Katende (David Oyelowo). A former street kid, the part-time mentoring missionary notices the girl peeking through the wall and beckons her to come inside. Immediately the other kids pick on her, turning away from her because she smells. She puts up a fight, though, winning Robert’s admiration (“This is a place for fighters”), and he assigns the youngest girl to teach Phiona the ropes. The subsequent sequence practically turns into a mini-STEM lesson: Phiona piece-by-piece learns to analyze the board, plan her moves, and consider the consequences. The movie doesn’t delve deeply into the rules of the game; viewers won’t come away knowing the difference between a rook and a knight or the sport’s historic origins in India but will come away learning that the small (the pawn) can become big (a queen) and the king is the “president,” protected by his minions. Crothers states flat-out that chess is not a spectator sport, yet director Mira Nair makes the game suspenseful and cinematic, thanks to the reactions of the actors and extras watching Phiona’s every move. The girl has hardly been to school and has never read a book on chess, but she has instincts and a competitive spirit—examining the chess board, she sees eight moves ahead. Her standing skyrockets when she, in short time, begins beating the boys. Her status increases further when she and her mates, called the Pioneers by Robert, go toe-to-toe with the older students at a posh private Catholic school. One sign of culture clash: the Pioneers take the blankets off their beds in the dormitory and sleep on the floor under the bed frames. The film’s focus remains fully on Phiona, her family, and Robert. The latter works for Sports Outreach Institute, a Christian organization run by American evangelicals who utilize soccer as a means to proselytize in the country’s most destitute areas, and it was Robert’s initiative to introduce chess to the program. His life parallels Phiona’s in many ways: his mother died when he was young, and he was virtually orphaned by a father who did not accept Robert into his other family. Through his prowess at math and soccer, Robert won a scholarship to finish school and study engineering at university. Not mentioned here is that Phiona’s tuition was paid by an Andrew Popp Memorial Scholarship, funded by an American couple in memory of their only son and sponsored by Sports Outreach. While the script acknowledges the importance of faith for Phiona, Robert, and others (a pint-sized chess player whispers the Lord’s Prayer before a competition), it plays less a central role on-screen than in book, where Katende attributes Phiona’s transformation to becoming born again—her demeanor radically changed from quarrelsome to graceful. Crothers also notes that she worships every day and continues to practice chess at church. In other departures, William Wheeler’s screenplay tweaks several episodic and involving conflicts that are suggested in the source material. It plays up the initial opposition by Phona's mother, Harriet (Lupita Nyong’o), to her playing chess and heightens the bickering between Harriet and her oldest teenage daughter, Night (Taryn Kyaze), who has run off with a slick older man. This doesn’t prevent Harriet from begrudgingly accepting the money he sends to Night’s family, though. And lest the film canonize Phiona, there are later pointed reminders that she’s barely a teen. After traveling for the first time abroad to Sudan for a tournament, she experiences the good life in her hotel: a bed of her own and three meals a day. Returning to Katwe, she has to scrounge for food daily and go back to living in a 10 x 10 windowless room with her entire family; her behavior becomes sullen and withdrawn. Throughout Nair directs confidently, as though it is understood that Phiona’s remarkable prowess is attention-getting enough without resorting to heavy melodrama. Her light touch is evident even when the actors offer bite-size sermons—“Sometimes the place you’re used to is not where you belong.” Her movie inspires, not insists. (Nair has lived in Kampala for more than 20 years, where she established an annual East African filmmakers’ laboratory, Maisha Film Lab. Queen was filmed in Uganda and South Africa.) The film had its world premiere earlier this month at the Toronto International Film Festival, where it placed second runner up for the Grolsch People's Choice Award; not so shabby, considering there were more than 200 films eligible for the prize. Meanwhile, Phiona has gone on to become the first woman chess master candidate from Uganda. At the time of the book’s publication, there were only 22 female grandmasters in the world. Directed by Mira Nair 124 min. Rated PG Queen of Katwe opens in New York City and Los Angeles September 23, nationwide September 30.