By Mary Shaffer
and Jerry Bunin
The Tribune

Never trust a movie with a Roman numeral in its title.

"Jaws" (1975) kept us out of the water. "Jaws II-IV" kept us out of the theater.

Movie serials span film history: from the silent "Perils of Pauline" to Andy Hardy, James Bond, Luke Skywalker, Indiana Jones, and "Star Trek."

Starting in the mid-1970s, sequels to blockbuster hits twisted the tradition as Hollywood eagerly cannibalized itself in search of box office gold instead of new ideas.

"Batman Returns" (1992) is typical. It eclipsed "Batman" (1989) in opening weekend receipts and may ultimately make as much money, but it's not nearly as good. It has too little plot, too many villains, takes too long to develop them, and virtually ignores Batman, the most interesting character.

"Terminator 2: Judgment Day" (1991) is the exception. It surpassed "The Terminator" (1984) in box office receipts and was equally memorable.

Most sequels are forgettable. Hollywood sees a moneymaking formula and tries to repeat it, cynically assuming audiences will pay to see the same thing twice. Unfortunately, audiences have done just that, although only a few sequels are worth seeing.

A good sequel should say something new while expanding the plot. The story should be absorbing on its own without relying on the original and should have characters worth knowing better.

Australian filmmaker George Miller did that in "Mad Max" (1979), his trendsetting, action-adventure trilogy about Max's metamorphosis into postapocalyptic legend. Each film is complete yet part of a larger vision, tracking Max's mythic journey as our civilization declines into chaos and begins a new world order.

Max (played by then unknown Mel Gibson, whose voice is dubbed in the low-budget original) and our future evolve in each film. He is transformed from ordinary police officer into self-imposed, nomadic "Road Warrior" (1981) to lonely Pied Piper reluctantly leading the next generation "Beyond Thunderdome" (1985).

Francis Ford Coppola used three films the same way to tell the story of "The Godfather," earning several Oscars, including Best Picture of 1972 and 1974 and a Best Picture nomination in 1990.

It is the quintessential gangster film and one of the best films about America, a rich saga of sin, corruption and redemption that explores the American dream through the Corleones, a clan of Sicilian immigrants.

"Part 2" stands out. It's both prequel and sequel to "The Godfather," using the past and present to expand and comment on each other and foreshadow the future.

Coppola's style and vision are so consistent that he successfully re-edited the first two films sequentially into "The Godfather Saga" (1977), an equally absorbing TV miniseries.

"Part 3" is the weakest, partly due to the absence of Robert Duvall as family lawyer Tom Hagen.

But as "Ghostbusters II" (1990) and "Another 48 Hours" (1990) showed, having the same characters, cast, crew and writer-director doesn't guarantee a good sequel if the script isn't as inventive as the original.

Yet occasionally a sequel succeeds despite itself.

In "Die Hard" (1988) and "Die Hard 2: Die Harder" (1990), Bruce plays the same wisecracking cop single-handedly battling authorities and terrorists in a confined setting at Christmas. His wife's life is threatened. And a sleazy TV news reporter tries to capitalize on the situation.

In "Die Harder," a renegade American military unit at Dulles International Airport on the East Coast replaces the original's international terrorists in a high-rise, Los Angeles office building, but the basic formula is the same.

Yet it works because Willis creates a memorable character in a film with remarkable stunts and special effects. Great characters, including villains, can make great sequels.

One of the most memorable adversaries from the 1960s "Star Trek" TV series, Khan (Ricardo Montalban), was successfully revived in "Star Trek II: The Wrath of Khan" (1982).

And the key to both "Terminator" films and "Aliens" (1986), another successful sequel, is how writer-director James Cameron successfully pitted sympathetic but vulnerable protagonists against a seemingly unconquerable villain.

However, a great villain alone is not enough.

The "Predator" (1987)--an invisible alien hunting humans for sport--is among the most intriguing movie villains ever. And "Nightmare on Elm Street" (1984) has a terrifying premise--a monster attacking through dreams.

Four sequels eventually turned Freddie Krueger from nightmare to lunch box icon. And "Predator 2" (1990) merely changed the scenery, multiplied the body count and forgot that the original worked because the Predator battled a strong but fallible hero (Arnold Schwarzenegger).

Too often, sequelmakers forget why the original film succeeded. Sylvester Stallone's "Rocky" (1976) is a genuinely stirring tale of a two-bit fighter making the most of his one big opportunity. Winning isn't as important as trying your best when your chance comes along.

Then Stallone sold out his own character, making four sequels extolling just the opposite, turning Rocky from being true-to-life into a cartoon figure battling caricature villains and causes.

Stallone isn't the only sell out. Seeing a bad sequel rewards bad filmmaking. If you don't go, maybe Hollywood will stop making them on purpose.

So before you spend anything on "Alien3," "Lethal Weapon 3," "Honey I Blew Up the Kid," and "Home Alone 2" this year, ask yourself how many good sequels have you seen.

Mary Shaffer works at Cal Poly. Jerry Bunin is a Telegram-Tribune reporter. They hate sequels, but still see them, hoping to find the exceptions.