“City of Men” is set in Dead End Hill, one of the shantytowns that drapes the steep slopes above the beaches and upscale districts of Rio de Janeiro. It’s a place of hopeless poverty, crime and deadly turf battles among rival gangs. Director Paulo Morelli doesn’t stint on the violence, but a story of friendship is the true heart of his engrossing film.

Laranjinha and Acerola — renamed Ace and Wallace for English-speaking audiences — have been friends since childhood and are about to turn 18. Ace (Douglas Silva) is already a father and is caught between the conflicting forces of adult responsibility and the hormonal impulses of a male teen. He mans a guardhouse for his livelihood.

His friend Wallace (Darlan Cunha) drives a motorbike-taxi and is single, though sweet on a young woman of the neighborhood.

One of the boys’ bonds is that they both are fatherless. Ace’s dad was murdered and Wallace’s is unknown to him. He is tracked down in the course of the movie and there is an awkward reunion with his son. But the father, Heraldo, makes a confession that drives a potentially fatal wedge between the young friends.

Matters become further tangled when Ace and Wallace are pulled into opposing sides in the war between gangsters Midnight (Jonathan Haagensen) and Fasto (Eduardo Piranha) and their casually homicidal underlings.

“City of Men” is a spinoff of the popular Brazilian television series of the same name. The series was itself inspired by “City of God,” a widely lauded film by Fernando Meirelles that also looked knowingly at Rio’s ghettos and their wretched inhabitants. Meirelles is a producer of “City of Men.”

Actors Silva and Cunha carry on the same roles they played in the TV series and it shows; their utterly convincing performances bespeak deep familiarity with their characters. They benefit from strong supporting performances, most notably that of Rodrigo dos Santos as Heraldo, and from cinematographer Adriano Goldman’s vivid micro- and macro-views of Dead End Hill.

The film stumbles during the scenes of mindless shooting, when it’s often hard to tell who is shooting whom. But it regains its feet when it returns to the uplifting story of two good men who battle prodigious odds not only to sustain their friendship but to break multi-generational cycles of poverty and parental abandonment.