Mark the '80s as the Decade of the Ninja, the newest wrinkle on an American fascination with martial arts that began in the '50s with judo, moved to karate and kung fu in the '60s and '70s and has now discovered ninjutsu, the 2,000-year-old "art of invisibility" taught in Japan. Count on this new outlaw warrior's becoming increasingly visible if films like "Enter the Ninja" are successful at the box office.

"Enter the Ninja" starts off with the entire preview that preceded it in a dozen metropolitan theaters: A white-clad figure, Cole, is stalked through a forest by a dozen maroon-clad figures who become more maroon as Cole slices and dices with a sword, bow and arrow, sharp stars, caltrops and tegakis (don't worry what they mean--they hurt). Behind them all is another stalking figure, Hasegawa (played by the stone-faced Sho Kosugi, all-Japan karate champion), dressed in black. Guess who the bad guy is?

Cole, played by a stone-faced Franco Nero, turns out to be the first Westerner to become a scroll-carrying master of ninjutsu, but it takes almost the entire film to provoke him into utilizing the nasty skills learned in the opening reel. By then, relying on the traditional chop 'em-sock 'em-kick 'em technique of all too many badly dubbed imported films, Nero has managed to kill or at least maim close to a hundred bad guys who are working for A Real Bad Guy, stone-faced Christopher George as the greedy Venarius. Venarius wants the farmland owned by stone-faced Alex Courtney and puffy-faced Susan George. Knowing there is oil in them thar grounds, Venarius sends for a bad Ninja, counting on Hasegawa's telling the traditional "hired assassin" line to remove the farmers.

The plot limps along, looking for convenient excuses for Ninjas to enter into brawls against such likely odds as 20 to 3, 14 to 1, back up to 40 to 1, then down to 12 to 1 and, finally one on one--good Ninja against bad Ninja in an all too brief encounter in a cockfighting arena surrounded by corpses and adorned with the admonition that "the judge's decision is final." One marvels at their energy because, by the film's end, they must both be tired assassins.

As so often happens in these films, none of the reasoning, acting or dialogue is particularly bright, much less believeable. The enraged Venarius, tripping over bodies, keeps screaming, "Where the hell is my Ninja?" as if he were looking for a pen to sign checks with. Nero, doing a slow burn when he spots his evil counterpart, manages only to describe him as "someone I went to school with in Japan." No one seems to mind being killed by a good Ninja, just surprised. Ultimately, it's hard to decide which is more deadly, the action or the dialogue.

The best directing in the film comes from fight choreographer and ex-karate champion Mike Stone, who obviously gets his kicks in, while producer-director Menahem Golan is obviously counting on the proven box office appeal of this kind of film. For the purist, one can only recommend walking in for the last 15 minutes and staying for the first 15; the rest has been shown many times before.