As overused film tropes go, the “wronged guy with a gun” plot is right up there with heist pics and mob capers.

That said, director Jeremy Saulnier does an admirable job of breathing new life into a tired form, constructing a realistically sweaty and jittery descent into awkwardly executed violence for Dwight (Macon Blair), a man whose life was derailed when his parents were murdered years earlier.

Upon learning the killer’s getting out of prison, Dwight — who now lives like a drifter, bearded and filthy — tracks him down and waits for his moment to strike.

Predictably, one attack begets another, and soon Dwight’s at war with the man’s entire hillbilly family (which includes, curiously, Eve Plumb, a k a Jan Brady).

Sparse of dialogue, terrifically ominous and full of low-key, high-quality performances, “Blue Ruin” is a vigilante tale even haters like me can get behind.