Three blood brothers find their oath tested by battle and personal rivalry in "The Warlords," a meaty drama of friendship, ambition and betrayal set during a bloody civil war in 19th-century China.

HONG KONG — Peter Chan’s period actioner “The Warlords” delivered plenty of action at the B.O. in its opening weekend. In China the film quickly notched up 90 million yuan ($12.2 million), putting it ...