Steven Spielberg is a one-man fantasy factory. His hits include the adventurous ''Jaws'' and the kinetic ''Raiders of the Lost Ark,'' with the charming ''Close Encounters of the Third Kind'' in between. All earned glowing reviews, huge audiences, and piles of money for their studios.
Will the Spielberg winning streak continue? This month the young filmmaker has two otherworldly treats in store, and both have already generated excitement in the trade. One is E.T. The Extra-Terrestrial, a grade-school version of ''Close Encounters'' with a cuddly spaceman in the title role. The other is Poltergeist, a phantasmic ghost story set in the California suburbs.
Of the two, ''E.T.'' takes the most risks. The main character is a young child, and the story is a perfect preteen fantasy: Imagine having your own alien living in your bedroom, with nobody - not even Mom--in on the secret. Later you introduce him to your brother and sister, and when Halloween comes, you dress him in a sheet and take him trick-or-treating. He's full of surprises and special powers. And all he asks is a little help contacting his home planet, so he can get back home after a while.
It's quite sweet, really, and some of it is enormously funny. In fact, it would be an ideal family film if not for a few vulgar words, and a sci-fi medical sequence preceding the ''Peter Pan''-style climax. What's commercially risky about ''E.T.'' is that - as Spielberg readily admits--the hero is a lot younger than the ''core audience'' of teens and young adults that Hollywood pursues so eagerly these days. And the action is gentle, with hardly a shred of violence or vehemence. What if teen-agers find ''E.T.'' too tame, and adults consider it too coy? It could be the first Spielberg flop since ''1941.''
But it probably won't be. Spielberg is a canny filmmaker, and he has given ''E.T.'' a sly wit that will probably pull the picture through. As for ''Poltergeist,'' it's hard to imagine how this spook-filled romp could fail. The buildup is careful and deliberate, leading to an explosion of shockers from the ''Raiders'' bag of tricks, cleverly leavened with humor. While it's not for young children, and contains a few vulgarities of its own, its natural audience of ''Lost Ark'' fans will be captivated before the first reel has unspooled.
How has Spielberg managed to pull two major entertainments from his sleeve in a single season? There's no magic involved: He had a lot of help, that's all. Some of that help came from filmmaker Tobe Hooper, who is listed as director of ''Poltergeist,'' with Spielberg credited as producer. Unfortunately, this partnership has led to recriminations from Hooper, who apparently feels his contribution to the picture has been slighted.
What does Spielberg want to accomplish in pictures like ''Poltergeist'' and ''E.T.''? Discussing his work with a few journalists in New York the other day, he expressed a fondness for larger-than-life adventures in garden-variety surroundings. Both new films take place in suburban areas where dullness is the rule, recalling Alfred Hitchcock's preference for ordinary heroes and suspenseful adventures that strike in broad daylight. According to Spielberg, the suburban reality of ''Poltergeist'' and ''E.T.'' is the ideal background for a ''battle between the fantastic and the mundane,'' which is what most of his films are all about.
Spielberg's movies have been criticized for frivolity--a just accusation when aimed at ''Raiders'' or ''1941,'' which lapse into old formulas instead of looking for new insights, deep meanings, or at least fresh cinematic thrills.
But there's a streak of the sublime in Spielberg, along with his weakness for standard movie conventions. When he concocted ''Close Encounters of the Third Kind'' a few years ago, he proved himself capable of truly audacious filmmaking--combining lavish visual delights with a philosophical humor and a childlike awe that boldly ran against the contemporary grain.
Anyway, says the young director, ''Movies are frivolous, fantastic, unbelievable. The suspension of disbelief is the whole point. It's just a question of whether you're suspending your disbelief for an 'Ordinary People'--accepting the idea that those histrionics occur in every family--or for a 'Star Wars.' It comes to the same thing.''
What is his own goal? ''I want to make movies you can't tune into right away. I want to be more original than that. I loved 'Chariots of Fire,' and maybe I could make a picture like that in five years - maybe I'll move into a more human naturalism. But not today. Today I'm on a different track, and I can't tell where it's going right now.''
Perhaps it takes a critic to tell Spielberg that his work is pretty ''human'' and ''natural'' already. For all the flash and fantasy of his latest films, they have a clarity, an everyday credibility, and a sense of family warmth that are often missing in more mundane pictures. Even when the poltergeists turn vicious and the E.T. unleashes his magical powers, these movies still revolve around the family closeness and parent-child love that are so carefully established in the opening scenes.
The young hero of ''E.T.'' is a boy named Elliott who never looks quite at home in the world. ''There's lots of me in Elliott and Elliott in me,'' says Spielberg. ''I only regret I wasn't such a neat kid.'' What was Spielberg like as a child? ''I was a weird little outsider,'' he says with a smile. ''At 12 years old I was living in Arizona and making 8-mm movies, and the neighbors thought I was crazy. They couldn't understand why I was dressing their children in German and Japanese uniforms and staging battle extravaganzas.''
In later years, Spielberg found himself the only member of his freshman class who knew what he wanted to major in. ''I wanted to be a movie director,'' he recalls, but his grades weren't strong enough for transferring to a school with a film program. So he made 16-mm experimental movies, learning and creating at the same time. Today he misses the ''fraternal'' experience that some other filmmakers had during their college years - the Coppola-Lucas-Milius crowd, for example, from the University of Southern California. ''I never had that group feeling,'' he laments. ''My college friends were all strange. I wished I could be around normal people like filmmakers!''
When casting a child to star in ''E.T.,'' Spielberg looked for two qualities: awkwardness and honesty. ''That's the kind of kid I grew up with,'' he explains. But it wasn't easy to find these attributes. ''I kept getting auditions from kids who looked like they'd been playing Las Vegas. At seven years old, they had more credits than I do! It's better to get a child who's lost, and needs guidance - a shy kid who internalizes a lot. When I found Henry Thomas, I saw the chance for an adult performance to come from a child's body. He's very gentle, and very controlled. He was just what I needed.''
Thus prepared, Spielberg fashioned ''E.T.'' to be a movie he'd like to see, not a movie that would automatically thrill a huge audience. ''I made 'Poltergeist' for the young audience, and I made 'E.T.' for myself,'' he says.
What's next for Spielberg? A whole list of projects. First will come ''The Twilight Zone,'' based on the memorable television series. It will comprise four stories - two originals, two remakes from the TV show - directed by four filmmakers. Spielberg's own episode will be a remake of the fantastic yarn about a little boy who can control people with his mind, written by veteran fantasist Richard Matheson. Other episodes will be directed by John Landis, Joe Dante, and George Miller.
Next will come ''Always,'' a feature-length remake of the 1942 drama ''A Guy Named Joe,'' with Spencer Tracy and Irene Dunne. Spielberg says this will be his first ''adult love story,'' but again there's a twist: ''The leading man isn't alive. He's a ghost.'' Spielberg saw the original on TV when he was 14, and loves it dearly. There's even a clip from it in ''Poltergeist.''
And yes, movie fans, there will be a follow-up to ''Raiders of the Lost Ark, '' directed by Mr. S. himself. In fact, he says, ''there will be a sequel if I have to break into the studio vault and steal the money.'' Why? ''Because the kids won't leave me alone.'' Sounds like a very good reason.