The Revenant Leonardo DiCaprio, Tom Hardy, Domhnall Gleeson. Directed by Alejandro González Iñárritu. Rated R. Opens Friday.

Life is not easy for Hugh Glass (Leonardo DiCaprio), the real-life fur trapper and frontier guide whose brush with death in 1823 inspired Michael Punke’s 2002 novel The Revenant (a French word meaning “returned” or “reborn”), and now this film adaptation. First, the party Glass leads is attacked by Native Americans—a slaughter that director Alejandro González Iñárritu (Birdman) shoots as a long, gory, chaotic nightmare. Then, Glass, who survives, gets horribly mauled by a bear, to the point at which it’s taken for granted that he’ll soon die. When carrying his litter becomes too arduous, the ranking military officer (Domhnall Gleeson) orders trapper John Fitzgerald (Tom Hardy) and a boy named Jim Bridger (Will Poulter) to stay behind with Glass and keep him comfortable until the time comes to bury him. Fitzgerald has other, less charitable plans, however, and Glass winds up having to dig his shattered body out of a shallow grave and trek 200 miles across unforgiving and/or hostile terrain in an effort to take revenge.

Much of the publicity surrounding The Revenant—ignoring goofy reports that the bear rapes Glass (it does not)—has emphasized how much genuine physical discomfort DiCaprio experienced while making the film, which was shot on location in various freezing-cold locations (mostly Canada and Argentina). Behind-the-scenes horror stories shouldn’t matter to audiences as much as they likely do to Oscar voters, but there’s no question that watching Glass suffer as he struggles to survive constitutes this film’s primary appeal. While DiCaprio doesn’t really get the chance to give a great performance, he does manage to convey the character’s intense will to live, which is motivated less by ordinary self-preservation than by his furious need to see frontier justice done. So long as The Revenant sticks to his extreme efforts, which at one point include taking refuge from a storm inside a dead horse’s belly, it’s gripping entertainment.

The revenge story itself, on the other hand, never quite catches fire. Iñárritu co-wrote the screenplay with Mark L. Smith (Vacancy), and they’ve added a personal element to Glass’ ordeal, absent from Punke’s novel, that feels like overkill (and also opens a gaping plot hole—in these circumstances, there’s no reason for Fitzgerald to leave Glass alive, even under the mistaken assumption that he’s mortally wounded). Furthermore, Hardy can’t find an interesting angle on the stock villain he’s been handed, apart from transforming his lines into a barely intelligible mumble-growl. The movie’s inevitable mano a mano climax disappoints, which makes Glass’ single-minded implacability feel retroactively misdirected … or, worse, like nothing more than a means for DiCaprio to finally win some awards. It’s a movie devoted solely to prowess and endurance, on both sides of the camera.