Summer Film War Starts in Earnest : Movies: ‘Alien 3,’ ‘Encino Man’ and ‘Far and Away’ go head-to-head with each other Friday--as well as facing the monster hit ‘Lethal Weapon 3.’

With the torrid pace of ticket sales for “Lethal Weapon 3” showing little sign of slowing, there’s a real cliffhanger-in-the-making as three more major movies arrive in theaters Friday.

Call it, “Showdown at the Multiplex.”

Opening in thousands of theaters Friday are:

* “Alien 3,” with Sigourney Weaver doing battle with the slimy, horrific outer space creature, in another twist of the same plot that has proven extremely popular with audiences twice before.

* “Encino Man,” a comedy about a frozen caveman who somehow thaws out and is discovered by Pauly Shore, the MTV personality.

* “Far and Away,” starring Tom Cruise and Nicole Kidman in a romantic period adventure that takes them from Ireland to Boston as immigrants, and finally to the wide open plains of Oklahoma.

But all three go face to face with “Lethal Weapon 3,” the action-oriented police movie starring Mel Gibson and Danny Glover that broke box-office records last weekend.

In its first three days, the Warner Bros.-distributed movie grossed a huge $33.2 million, to become the second biggest non-holiday weekend in recent film history.

In the first two days of this week, “Lethal Weapon 3” continued to do big business, according to Exhibitor Relations Co., a firm that tracks box-office data.

There are various theories floating around Hollywood today as to which movie--if any--will be hurt the most by the others.

Some studio sources, who commented only on the condition of anonymity, suggest that “Lethal Weapon 3” will continue dominating the market, cutting into the potential of “Alien 3” and “Far and Away.” Others say the crowds that went to see “Lethal Weapon 3” will naturally gravitate toward the action adventure “Alien 3.”

Another scenario has it that if “Lethal Weapon 3” cuts into the audience for “Alien 3,” that would, in turn, leave the non-action audience to head for “Far and Away” with the popular Cruise. “Encino Man” is an unknown quantity, observers say. But it has been popular with test-screening audiences, and is aimed at the teen market, which made Paramount’s “Wayne’s World” a big hit this spring.

“If the question is, ‘Can the marketplace handle four movies this weekend?,’ my answer is, yes it can,” said 20th Century Fox executive vice president Tom Sherek. “The fact that people are going back to the movies because of ‘Lethal Weapon’ is a good thing. It bodes well for a big holiday weekend. The people who have seen ‘Lethal Weapon 3’ hopefully will choose ‘Alien 3,’ ” he added. Whatever the outcome, the overall box-office take for the weekend is expected to be large, since Memorial Day weekend is traditionally one of the year’s most lucrative periods.

“Summer is a time when the market expands. There’s enough business to go around . . .” said Art D. Murphy, box-office analyst for Daily Variety, who noted that all the films could see healthy returns.

Murphy added that summer business doesn’t really heat up until school is out--about the time that Warner Bros. has scheduled “Batman Returns” to open. Business usually comes to a peak around the Fourth of July weekend.

Memorial Day weekend--a period from Friday through Monday--is traditionally considered the start of the summer movie-going season, when the major film companies typically fire their biggest shots. The hope is that the movies will play through June, July and beyond--in the season that accounts for about 40% of the year’s box-office grosses.

This year, the industry is hoping the summer will bring the movie audience back to the theaters after a winter and spring when the box office could hardly be called bountiful.

So far, the 1992 box office has lagged behind 1991, which lagged behind 1990, which lagged behind the all-time high year of 1989--the year that “Batman” helped boost sales considerably. Grosses and the number of admissions have been on a downturn ever since.

This year also did not have the benefit of a box-office surge from the Academy Awards, largely because most of the big nominees already had played themselves out by the time nominations were announced in February. The best picture winner, “The Silence of the Lambs,” had already been released on video.

The only good-sized hits have been the suspenseful “The Hand That Rocks the Cradle,” “Basic Instinct,” “White Men Can’t Jump” and “Wayne’s World.”

Last year at this time, the film industry opened its summer without benefit of a sequel, unlike the George Lucas/Steven Spielberg era of blockbusters opening on Memorial Day weekend.

Among the new movies opening on Memorial Day weekend 1991 were “Backdraft,” What About Bob?,” the ill-fated “Hudson Hawk” and the much-lauded “Thelma & Louise.” None of them really took off. “Hawk,” in fact, did a fast nose dive, but recovered somewhat by the time it reached European markets and home video.

The result was a shaky start for summer. Ticket sales didn’t begin turning around until the arrival in June of “City Slickers” and “Robin Hood: Prince of Thieves.” Those hits were topped a few weeks later on the Fourth of July weekend by the opening of “Terminator 2: Judgment Day,” which went on to become the year’s top box-office attraction, grossing $205 million in the United States and Canada and another $285 million in international markets.