Ingenious fantasies for the imaginative

Are you now, or have you ever been, a child who loves to read? If so, you might want to put your books away for a couple of hours and see ''The NeverEnding Story,'' a new movie from director Wolfgang Petersen.

I don't mean this is a literary film. It's a movie-movie, with some uninspired dialogue and enough special effects to choke a dragon.

But the main character is a kid with no time for TV or the video arcade. What he savors is a dusty old volume and a quiet place to read it. What he gets, from a strange old bookseller, is a mysterious tome that carries a special warning: Other books make you feel as if you're in the story, but this book makes you part of the story!

The symbol of the book (and also the movie) is a snake eating its own tail, an image long known to fantasy buffs. In the spirit of that unusual reptile, the film tries to become a Mobius strip, an endless loop dipping into both the real and the imaginary. The movie never quite manages this, but it does pull off a neat trick by integrating into one story a ''real'' hero and a ''make-believe'' hero - the modern American boy who reads the tale as we watch it, and a dreamed-up warrior lad who plunges through one fabulous adventure after another.

It's an ingenious idea, and at its best moments the film has a charm and fascination all its own. This is partly because it grabs us two ways at once: with the present-day plot about a likable bookworm who doesn't quite fit into the everyday world, and the fairy-tale plot about a youth who must save his land from destruction by a sinister force called the Nothing. The two stories begin to merge long before the end, and though the climax seems a bit forced, it's a pleasure when they clap triumphantly together.

The concept of ''The NeverEnding Story'' is so strong that I wish some details had been handled more cleverly. The fantastic creatures are mostly endearing - there's a dragon that looks like a cocker spaniel - but they often seem puppetlike and their voices don't sound real. As you might expect in a fantasy world with the old-hat name of Fantasia, there are corny touches. And some scenes (a horse drowning in a swamp, the hero stabbing a monster) are sad or scary enough to put the movie off limits for very young viewers.

Still, fantasies as hearty and original as this are rare at the movies, and if audiences aren't already sated with less thoughtful fare like ''Indiana Jones'' and ''Ghostbusters,'' this could be a major summer hit.

For moviegoers familiar with director Petersen, the picture's biggest surprise is that he tackled such fantastical material in the first place. He's best known for the World War II action drama ''Das Boot'' - the most successful foreign film ever released in the United States - and has explored such worldly subjects as homosexuality in ''The Consequence'' and chess in ''Black and White Like Day and Night.''

It's also unusual to see an English-language movie from this West German filmmaker - although it was shot largely at the Bavaria Studios in Munich, with additional photography in Spain and Canada.

The blond-haired, blue-eyed Petersen visited New York recently to launch ''The NeverEnding Story,'' and I asked him about these unexpected twists in his career. Explaining the film's American setting and ambiance, he said ''Story'' was the most expensive West German production ever - the budget was $27 million, large even by Hollywood standards - and the producers wanted it to have a sure-fire chance in the huge American market. As for German audiences, they are used to dubbed-in dialogue, and Americanisms don't faze them. And sure enough, since opening four months ago, ''Story'' has become a monster hit with Germans, helped by the overwhelming popularity of the Michael Ende novel it's based on.

Why did Petersen tackle such a fanciful tale after the realism of his previous work? ''I spent a year shooting 'Das Boot' on a submarine,'' the director replies. ''After that, I needed to approach something warm and positive!

''And you know,'' he continues, ''the two films aren't really that different. It's true 'Das Boot' is realistic and has a sad ending. But audiences react to the sadness with positive feelings: They say 'Never again!' and they leave the theater in a hopeful mood, hoping such war and killing can be avoided from now on.''

Petersen sees an ''uplifting'' message at the heart of ''The NeverEnding Story,'' too. ''The little boy reads about a place that is dying because imagination is dying,'' he says. ''And he learns that he can help the place with his own dreams, wishes, and ability to be creative. This is a message people want to hear. They are tired of the fear we have today - the fear that politicians and industries have taken control of the world away from them. People want to know their own minds and creativity are important and can make a difference.''

Besides offering this message, Petersen feels his ''Story'' may be helping to usher in a new era of West German cinema. ''A whole generation of our directors is gone,'' he says. ''Wenders has left our country, Fassbinder is dead, Herzog is off someplace in the world. New filmmakers must come to take their place, and I think a new attitude is being felt: We are realizing that movies must speak to the popular audience, not only to the few.

''We still have young directors who experiment, and we need them, but we are remembering that films must speak to everyone. And the change is being felt, because Germans are going to German movies in large numbers, and that is a wonderful new thing.'' 'The Last Starfighter'

Today's young viewers like to identify closely with their heroes, and the movies are responding to this yen. You can see it in ''The Last Starfighter'' as well as ''The NeverEnding Story,'' two films that share a key plot device: Both are about regular American kids (like most of the audience) who get recruited to join an exotic adventure in another world. In each case it's a commonplace object of communication or entertainment (a book or a video game) that brings the invitation.

It's not an ordinary game that lures one bored young man to become ''The Last Starfighter,'' though - it's a secret test of space-fighting ability. When he breaks the high-score record, he's contacted by a wheeler-dealer from another galaxy, promising him glory and adventure if he'll help win an interstellar war. Being a quiet sort of guy, he'd rather stay home with his girlfriend, but he changes his mind when he learns the fate of the universe is at stake. Fun is fun , but the fate of the universe - well, that sounds pretty serious.

It's an ideal teen-age fantasy: Those games you waste your time with are really preparing you for a great destiny! In the hands of Steven Spielberg (who came up with an ideal preteen fantasy in ''E.T. the Extra-Terrestrial'') this might have sprouted into a memorable epic.

In the less experienced hands of director Nick Castle, it's diverting and amusing. But there are problems. The pace is rushed; the climaxes don't generate much real emotion; and the filmmakers twist the story into any shape that pleases them, until even matters of life and death lose their meaning.

It's a minor-league variation on ''Star Wars'' and ''Close Encounters of the Third Kind,'' full of ripped-off Spielbergiana, like starry skies and a bratty little brother.

What bothers me more is the promotion for the film. Not just the ''coming attractions'' trailer (which gives away too much of the plot), but the marketing tie-in with a real video game. Just as some movies are made largely to sell a sound-track album, are we now in for pictures geared to sell high-tech home entertainments? Here's hoping it doesn't become a trend.

That said, I must praise the computerized effects in the film itself, which are crisp and original throughout. And so are the performances - especially Lance Guest as the starfighter, Dan O'Herlihy as his alien copilot, Catherine Mary Stewart as his girlfriend, and Robert Preston, whose fast-talking Centauri is a spacey version of the Music Man he used to play. He's a pleasure to watch, and if there's a sequel, you can bet he'll be on board.