The weapon of choice for Dochi (Ha Jung-woo) in “Kundo: Age of the Rampant”: two meat cleavers, the tools he used while working as a butcher. (Well Go USA Entertainment)

For Western audiences, Korean period dramas can require too much historical knowledge or rely too heavily on patriotic fervor. Neither is a problem with “Kundo: Age of the Rampant,” a mid-19th-century escapade whose electric-guitar flourishes announce its irreverence. Director Yoon Jong-bin’s principal interests are rollicking combat scenes and rousing underdog triumphs.

The movie’s narrative backdrop is genuine. The late Joseon Era was known for corruption among the aristocracy, and poverty and hunger for nearly everyone else. Bandit clans called “kundo” were common, and some of them had the Robin Hood-like ethic of the group celebrated in this tale.

The history lesson pretty much stops there, however. The movie owes less to real events and more to Chinese kung fu flicks — yes, there’s a battling monk — and Akira Kurosawa’s classic “Seven Samurai.” And the Ennio Morricone-derived score is just one echo of the spaghetti westerns that also inspired “The Good, the Bad, the Weird,” a 2008 Korean romp.

Like that film, “Kundo” combines dynamic action sequences with swaggering humor. The earthy dialogue may seem a little forced in subtitled translation, but the well-choreographed bedlam is freewheeling. Some of it borders on slapstick, although the movie is too bloody to be termed a comedy.

The first half of the more-than-two-hour tale introduces a bewildering number of characters. Ultimately, though, the movie becomes a grudge match between two men who’ve been wronged in very different ways: baby-faced villain Jo Yoon (Kang Dong-won) and well-meaning roughneck Dochi (Ha Jung-woo).

Both suffer because of their origins. Jo Yoon is the son of a nobleman, but his mother was a courtesan. For a time, he’s the only male heir, so his father accepts him. When a rival is born, Jo Yoon is displaced. That’s when he starts plotting of the deaths of various relatives, including a pregnant woman.

Dochi is a butcher, a member of Korean society’s lowest caste. When Jo Yoon offers him a job as an assassin, it seems like a step up. But Dochi balks at murdering a mother-­to-be, so Jo Yoon sends thugs to punish him. He escapes, badly burned, and joins the kundo. Where a samurai-style hero might brandish two swords, Dochi attacks with a cleaver in each hand.

Dochi’s getaway is a turning point both for him and the movie. In its second half, “Kundo” becomes robust and exhilarating. The filmmakers stage cast-of-dozens battle scenes and one-on-one showdowns with equal brio.

When it opened in Korea last month, “Kundo” set a box-office record, only to have it toppled seven days later by the equally bold and brutal “The Admiral: Roaring Currents,” the 16th-century naval epic that arrived in Washington two weeks ago. Both are fine examples of the energy that today’s Korean cinema is drawing from the past.

Jenkins is a freelance writer.

★ ★ ½

Unrated. At Rave Cinemas Centreville 12 and Cinemark Egyptian 24. Contains violence and torture, partial nudity and profanity. In Korean with subtitles. 137 minutes.