MOVIE studios normally rely on thousands of people to produce action-adventure movies such as the stormy ''Waterworld,'' which opened July 28. But if the movie's star, Kevin Costner, had any more of a say, there might have been only a single credit.
For Costner plays not only the role of Mariner - an aquatic hero in a globally-warmed, futuristic land - but also the parts of director, executive producer, and editor as well.
Costner is the latest in a long line of leading actors who have taken firm hold of a movie's production. From crafting the script to deciding what stays in the final cut, big-name actors are finding it necessary to leave their fingerprints all over a movie reel that has their name over the title.
''There are definitely some personalities and talents in Hollywood that have gotten to positions where they are accustomed to getting their way,'' says Jeff Jensen, an entertainment reporter for Advertising Age. ''Costner, Sylvester Stallone, and Clint Eastwood have not only been actors, but also producers and directors on previous projects, so when they are simply actors again, it is tough for them to let go of everything.''
Among movies showing this summer, the actors who directed themselves from the start of a picture, such as Clint Eastwood in ''The Bridges of Madison County'' and Mel Gibson in ''Braveheart,'' received positive reviews. It is when megastars like Costner and Stallone - who successfully have directed such blockbuster hits as ''Dances With Wolves'' and ''Rocky,'' respectively - try to meddle with the directors on their sets that things spiral out of control.
John Krier, president of Exhibitor Relations, a box-office and film research firm based in West Los Angeles, says he understands how these actors may think they can do a better job. ''It is not unusual in this business for the director to quibble with actors in the middle of the movie; even Orson Welles had flaps with his personnel.''
One of the more celebrated incidents between an actor and a director took place between the larger-than-life Marlon Brando and acclaimed director Francis Ford Coppola during the filming of ''Apocalypse Now.'' Paul Dergarabedian, executive vice president for Exhibitor Relations, says Brando ''was not prepared physically or mentally for his role despite the fact that he was being paid an enormous amount of money for the movie.''
No slouch himself, Coppola had previously directed both Academy Award-winning ''Godfather'' films. But in the end, he was forced to redo the ending to ''Apocalypse Now'' after seeing Brando, who had gained weight and shaved his head prior to his arrival on the Philippines set. These facts were confirmed in 1991 when Eleanor Coppola's riveting behind-the-scenes footage was released as a documentary called ''Hearts of Darkness.''
Brando was so powerful a star, says Dergarabedian, that he had free rein on the set. ''Everything basically revolved around him once he got there.''
The last-minute changes made to ''Apocalypse Now'' did not adversely affect the film, which was loosely based on Joseph Conrad's classic book ''Hearts of Darkness.'' In fact, one of the film's more memorable lines comes from the newly bald Brando whispering at the end, ''the horror, the horror.''
At the time, ''Apocalypse Now'' was the biggest budget movie ever, racking up $31 million in expenses. Fortunately for its backers, United Artists, the movie garnered an impressive $72 million.
In the case of ''Waterworld,'' personnel problems have helped push the movie's expenses over the $200-million mark.
When Costner saw the film's final cut, made by director Kevin Reynolds, he did not like the way his ''dark and edgy'' character was portrayed, Jensen says. ''Costner went into the editing room and re-edited the picture because he was concerned with how the audience would view him after they left the theater.''
According to a recent article in Esquire magazine, Costner successfully pressured Universal Studios to have Reynolds removed from the editing room.
Stallone and Costner both have carefully crafted images, one as the American crusader for justice and the other as the good-looking hero, ''a Jimmy Stewart with muscles,'' Jensen says. In order for these actors to remain on top in Hollywood over the next 20 years, they need to ensure that they do everything they can to keep these personas intact.
Stallone's latest action-adventure film ''Judge Dredd,'' which had an $80 million budget, is not doing as well as expected after the actor feuded with director Danny Cannon throughout the shoot.
''For Stallone and Costner, whether the movie is good or not is irrelevant,'' Jensen says. ''What's most important to them is that the fans leaving the theater are still going to go out and see their next movie.''