SEOUL, DEC. 13 -- This week South Koreans will go to the polls amid fears of violence, intimidation, vote-buying, ballot-box stuffing and concerns about biased news coverage in the domestic press.

That will be the easy part.

Many people here believe the real test will come after Wednesday's vote, this nation's first in 16 years. South Koreans are gambling that, after 26 years in power, an authoritarian, military-dominated elite will give way to democracy without a violent revolution or countercoup.

Many Koreans say that their literate, increasingly prosperous population is in a better position to pull off such a political miracle than most societies. Despite all of the fears and rumors to the contrary, they say, the nation has conducted this presidential campaign with remarkable restraint, given the accumulated bitterness of the past decade.

But they also acknowledge that the problems facing them in the days, weeks and months after the election are more than formidable.

"No matter who wins," one businessman said today, "it's going to be a mess."

Wednesday's victor, almost certain to be elected with less than 50 percent of the vote, will face grave challenges from the start. If it is ruling party nominee Roh Tae Woo, the danger will be a popular uprising questioning the fairness of the vote; if an opposition candidate wins, the threat could come from the Army.

Some Koreans already are hoarding rice, noodles and other staples in anticipation of trouble, one source said today.

"The guy's going to be shaky no matter who wins," a western diplomat said recently. "Sixty percent of the people will have voted against him."

If the winner survives the immediate challenges, he will bump right into longer-term and possibly graver problems: trade pressure from the United States that could slow South Korea's export-led economy, virulent regional prejudice fanned by the campaign, rising expectations among all sectors of society after a year of exceptional economic growth and a fall of extravagant political promises.

"Whoever becomes the president, there will be strikes this spring, and they will be difficult to control," Kwack Tae Won, an economist at the Korea Development Institute, said last week.

Kwack and others find some grounds for optimism -- the fundamental soundness of the economy, for instance, and a budgetary cushion from the sale of government corporations planned for the next five years. Several people interviewed said that the Olympic games, scheduled to be held in Seoul next September, will serve as a brake on all special interest groups, since the games are a point of pride that no one wants to jeopardize.

"There's so much to lose for the country if something really does go wrong," the businessman said. "I think that realization finally is beginning to sink in, in the places where it needs to sink in."

But the prospect is far less rosy than many people expected when President Chun Doo Hwan, acceding to weeks of street protests, promised six months ago to allow this election. Chun's concession seemed to pave the way for a showdown, after years of coups and constitutions imposed to prolong regimes, between the forces of democratic opposition and the ruling elite.

That struggle never took shape, however, because the two longtime leaders of the opposition -- Kim Dae Jung and Kim Young Sam -- both decided to run. With the entry of a fourth candidate, former premier Kim Jong Pil, the campaign turned into a bitter, name-calling affair with no clear favorite and no candidate who seemed to rise above personal ambition.

With pollsters predicting that a one-third plurality might bring victory, the popular opposition leader Kim Dae Jung has warned the government, with increasing ferocity, not to "steal" the election. In the text of a speech he gave to a huge rally in Seoul today, Kim warned that election fraud could lead Chun to a fate like Choi In Kyu, a home affairs minister who was executed for masterminding vote fraud before a 1961 coup.

A Kim aide at the rally, T.C. Rhee, said that if Roh wins through cheating, "there will be a rebellion, there will be a revolution -- a revolution in the sense that there will be blood, there will be weapons."

Many people believe that residents of Korea's underdeveloped and neglected southwest, Kim Dae Jung's stronghold, would react especially violently to his loss. An uprising there, in turn, could give some elements of the Army the excuse they are waiting for, some officials fear.

At the same time, some Army officers may fear a victory by one of the Kims. Plum assignments in government and industry for retiring generals may disappear, and although both Kims have repeatedly foresworn retaliation, some officers fear they will be held accountable for alleged past misdeeds.

"I'm sure they're worried about their future," an opposition politician with contacts in the military said today.

Roh Tae Woo, meanwhile, has portrayed the consequences of an opposition victory in terms almost as dire as Kim Dae Jung's and his supporters. The Olympics, the growing economy, the nation's stability, all would be "washed away," he has said.

Certainly, one western diplomat agreed, either of the Kims would face "incredible demands to straighten out everybody's problems at once." Kim Young Sam, who has portrayed himself as the centrist who can best guarantee stability, already has pleaded for a "honeymoon," but certainly no one is promising him one.

Assistant Foreign Minister Park Soo Gil said he does not expect a "honeymoon" or grace period even from South Korea's closest ally, the United States. With South Korea and Taiwan rapidly taking Japan's place as sources of the U.S. trade deficit, Park said he expects growing pressure on South Korea to revalue its currency and allow more imports.

"In pursuing economic interests, people and nations can be very merciless," Park said.

One economist said he believes workers and others will moderate their demands to make sure the Olympics succeed.

U.S. Ambassador James Lilley, looking to the period beyond this week's vote, has been recommending former president Gerald Ford's memoirs, "A Time to Heal," to his Korean acquaintances, according to official sources.

But if the Kim Dae Jung pocket calendars being handed out at today's rally are an omen, the prospects for the future are not bright. The calendars, with a picture of Kim on one side, go only as far as March 31.

Special correspondent Peter Maass contributed to this report.