Chow, who wrote and directed and also stars in “Kung Fu Hustle,” knows whereof he spoofs. There are traditional ploys in the genre, as there are conventions in the American western or the Japanese samurai films. Here Chow raises martial arts conventions to the nth degree.

The film opens brutally with the doings of the Axe gang, but right off we get the satirical element, as everything is quickly over the top. As for plot, it involves an attempt at extortion in a poor area known as Pig Sty Alley. But the neighborhood is not prepared to give in.

What follows is martial arts mayhem, with an odd assortment of characters, feats of heroism, special effects involving body expansion and zooming through the air, as well as running at super speed. The combat escalates and escalates, as does the violence, but it is comic book violence, not anything meant to be taken seriously. And always Chow’s heart is with the underdog. He, of course, plays the ultimate hero.

The film does go on a bit too long in overkill and overdrive. But the visual inventiveness consistently makes one marvel at the techniques and skills that went into making this comedy. Chow also injects some romance in the film in the form of a bond between two children that is expressed later in adulthood. But he doesn’t lose the comic touch.

At the end a kid with a runny nose looms as a reminder of fascination with martial arts that can be passed from generation to generation.