• ENTER THE DRAGON is a superior action thriller that is likely to augment the already impressive popularity of Kung Fu and allied martial arts. The plot is basically an adaptation of the early James Bond thriller, DR. NO, and like its predecessor ENTER THE DRAGON forsakes subtlety and believability in favor of incredible heroics and rip-roaring action. The late Bruce Lee stars as a master of the martial arts, recruited by Hong Kong authorities as an undercover agent to smash a worldwide opium-and-slavery ring, and at the same time to avenge his sister's death. Lee's acting is at times wooden and low-key, but his performance in the fight sequences is awesome. Capable support is provided by John Saxon as an American refugee seeking to escape his gambling debts, and Jim Kelly as a black revolutionary. Two supporting performers are also impressive: Shih Kien as the arch-villain bears an uncanny resemblance to Leonid Brezhnev, and Angela Mao Ying displays astonishing resourcefulness and fighting spirit as Lee's ill-fated sister, Su-Lin. Except for a stereotyped opening, the screenplay is effective and keeps the action moving at a fast clip. The fight sequences, though highly stylized, are more interesting and more believable than their Western counterparts. Special effects are used sparingly and intelligently, and the best is saved for last: a climactic fight to the death in a chamber of mirrors. This and all the other fight scenes were staged by the star, Bruce Lee, whose untimely death earlier this year robbed him of a promising career. Rated "PG."

• Even though movies about dying athletes are in danger of becoming a drug on the market, BANG THE DRUM SLOWLY is such a superior film in every respect that it should not be missed. The story is about a young professional baseball player who is dying of a rare disease, but who wants to continue playing as long as possible. The film's emphasis is not on his impending death, but rather on his and his best friend's efforts to hide his illness from an increasingly suspicious manager. The movie's dramatic effect, along with its humor and pathos, arises naturally from the plot, never once degenerating into tear-jerking soap opera. The performances, by a cast of relative unknowns, are impeccable. Michael Moriarty stars as the slightly dull-witted catcher playing his final season. Robert De Niro comes across simply and directly in the role of Moriarty's friend and protector. Vincent Gardenia deserves an Oscar nomination for his portrayal of a harassed manager attempting to cope with a volatile team. Tom Ligon has an interesting minor part as a guitar-playing, motorcycle-freak catcher. Although the life-style of baseball players on the road is rendered in a convincing manner, the game itself is de-emphasized in favor of interaction among the characters. No last-minute, ninth-inning saves here. In the occasional scenes of players on the field, slow-motion photography is frequently employed, and to good effect: the emotional meaning of the struggle is vividly etched in the players' faces. The straightforward screenplay by Mark Harris is based on his own novel. John Hancock's direction is cool and precise. Everyone associated with the making of this movie should be proud. Rated "PG."

• Despite its catchy title, 40 CARATS is considerably less than a gem of a movie, falling as it does into just about every pitfall that stage plays encounter when translated into film. Crippled from the start by an improbable and paper-thin plot, the movie is additionally laden with see-through theatrical mechanics, such as an endless series of double-takes and dramatic confrontations. Over what, you might ask? Well, it seems that this 22-year-old lad wants to marry a 40-year- old divorcee. Shocking, isn't it? Naturally, all the friends and relatives are aghast at this unconventional behavior, and our lovers find the path to true happiness strewn with myriad obstacles. Buried under several layers of this ridiculous plot are a few better-than-average performances and occasional bits of witty dialogue. Edward Albert is firm and decisive in his quest to marry Liv Ullmann, who is prim and proper and indecisive. Gene Kelly has a thankless, soppy-sentimental role as Miss Ullmann's worthless ex-husband. What are such nice people doing in a film like this? Rated "PG."