It is a cruel rule of thumb that extraordinary lives rarely make for extraordinary films. The more densely storied the personal narrative of its subject, the harder it is for dutiful screenwriters to resist tackling it whole, checking off every compelling accomplishment in thorough, linear fashion, even if such orderly diligence comes at the expense of more time-consuming character nuance. Critics have taken to calling this approach – not inaccurately – the “Wikipedia biopic,” though of course it dates back to the dustiest days of 1930s studio prestige drama, while Richard Attenborough effectively rebranded the genre in his own name decades later with the nobly dreary likes of “Young Winston” and “Gandhi.”

Attenborough comes frequently to mind while watching Justin Chadwick’s competent but predictably (perhaps inevitably) featureless “Mandela: Long Walk to Freedom,” the latest and largest of several attempts to cinematically totemise the most consecrated of all living politicians: South Africa’s first democratically elected president, Nelson Rolihlahla Mandela.

That’s not just because the film’s elevated but textbook-solemn tone so closely recalls “Cry Freedom,” Attenborough’s own stab at apartheid-era myth-making – nor because “Mandela”’s screenwriter, the reliably fusty William Nicholson, has twice worked with the British lord. “Cry Freedom” was released in 1987, three years before Mandela emerged a free man from the gates of Victor Verster Prison; Steve Biko may have been its worthy subject, but it was effectively a stand-in for a Mandela biopic that, at that heated point in history, had no satisfactory ending.

Chadwick, then, is making the film that many an august filmmaker has wanted to make for the better part of a quarter-century, and directs it with enough respectful anonymity to honor them all: the first official adaptation of Mandela’s 1994 doorstop memoir, produced by South Africa’s foremost industry mogul Anant Singh, it has the hefty but guarded presence of any authorized biography. It’s also the first film to follow Mandela from cradle to dotage. Recently, Bille August’s “Goodbye Bafana” and Clint Eastwood’s “Invictus” both attempted to capture the man entire by covering a more contained section of his life. That’s generally the approach of the more discerning and insightful biopic – see “Lincoln” or “Capote” for proof – but neither of those drab spirit-lifters felt equal to Mandela’s personal magnetism, and Chadwick’s more substantial film doesn’t come much closer.

To be fair, I’m not sure Mandela’s own sincere but shrewdly self-positioning book – written at the outset of his presidency, a delicate time of national healing when he very much needed to be all things to all men – does either. Mandela is and always has been a conflicted hero, one whose positively miraculous professional accomplishments sit in fascinating balance with the ruthless personal streak by which he achieved them: not just the romantic guerrilla action for which the political right continues to judge him, but his manifold failings as a husband and father. “Mandela” isn’t so hagiographic as to sweep those under the sprawling carpet – indeed, some of its most engaging stretches are those which cover the man’s early incarnation as a shark-suited lawyer and heedless township cocksman. But it does ultimately present those facets as immaterial in the face of his self-sacrificing Goodness, which overrides the filmmaking as much as it more justifiably does his historical standing.

Nicholson’s plainly overworked script scores points for showing us both sides of the man, but is rarely so deft or daring as to show them at once. Mandela is callous in one scene – invariably a domestic one, and most joltingly in those involving his first wife Evelyn (a too-swiftly discarded Terry Pheto) – and pious in the next, with the scales favoring the latter as the stakes of his political crusade escalate.

Guy Lodge is a South African-born critic and sometime screenwriter. In addition to his work at In Contention, he is a freelance contributor to Variety, Time Out, Empire and The Guardian. He lives well beyond his means in London.