[5] Norris plays karate champion Matt Logan, who is hired to assist an anti-narcotics police unit, who are being targeted by a killer.

While investigating a suspected drug den inside a sporting goods store, two plainclothes police officers are killed by a masked assailant using martial arts techniques.

In response, Officer Mandy Rust and Lieutenant Sam Dunne approach full-contact karate champion Matt Logan to train their unit in unarmed combat techniques.

The drug ring is run by Melrose, who uses his chain of sporting goods store to stash and distribute narcotics to dealers.

The screenplay, written by Oscar-winner and Shaft creator Ernest Tidyman, was based on a story co-created by martial artist and Norris' longtime associate Pat E. Johnson.

[citation needed] This was the film debut of martial artist and undefeated professional kickboxer Bill "Superfoot" Wallace.

Todd McCarthy of Variety wrote, "Though plot is far-fetched and production values aren't much superior to tv fare, likable protagonists and strong karate sequences will carry the day with the intended audience.

"[11] Kevin Thomas of the Los Angeles Times called it "a swift, taut, handsomely photographed thriller... made with more craftmanship than most martial arts movies.

"[12] Gene Siskel of the Chicago Tribune gave the film two stars out of four and dismissed it "just a poor excuse for a lot of fighting.

Not only does it move along at a faster clip than many a higher-budget film, but it's done without a lot of gore — no small feat in a martial arts movie ... Another plus is that the romantic leads, Jennifer O'Neill and Chuck Norris, actually seem to like one another; they're relaxed and at ease before the camera, and their scenes together are a pleasure to watch.

[15] Writer Elliot Hayden Parker, a former editor with the United Airlines magazine Mainliner, filed a lawsuit in Los Angeles County Superior Court against actor Chuck Norris, seeking damages of $15 million for the alleged theft of his feature film concept.

The complaint went on to say that Parker discovered that Norris had plans to make a movie using the same title as his article and outline without his participation.

Parker alleged that Norris’ second film, released in March 1980 and referred by its working title, Force of One, was “substantially identical” to his original outline.