Virginia's quadrennial spectacle of local and legislative election campaigns draws to a close Tuesday with voters deciding the fate of 3,000 candidates who together are changing the face of modern politics in the state.

They will do so in the year of the $1 million race, the season that many campaigns for state and county offices took to television for the first time and candidates accustomed to running on a shoestring hired consultants to mold their image and market their message.

Virginia polls will be open from 6 a.m. to 7 p.m. Tuesday. The most visible race in Northern Virginia is for chairman of the Fairfax County Board of Supervisors, a no-holds-barred fight between three-term incumbent John F. Herrity, a Republican, and Audrey Moore, a Democratic supervisor who has represented the Annandale district for four terms.

If measured in television air time and pure political venom, the clash between these two longtime antagonists has no equal in the state. Independent candidates James S. Morris Jr. and Robert T. (Terry) Robarge also are running.

Besides the chairmanship, the eight other seats on the Fairfax board will be filled, as will all spots on the boards of supervisors of Loudoun and Prince William counties. Two Democrats and two independent candidates are vying to fill a pair of at-large seats on the five-member Arlington County Board.

Additionally, Virginians will decide whether to approve a state lottery and will elect all 140 members of the General Assembly.

Across the state, running for those most political of offices suddenly became more expensive, more elaborate and, in some cases, nastier than ever.

"I'm hearing it from all localities: They're amazed at how much their candidates are spending," said Susan H. Fitz-Hugh, the executive secretary of the State Board of Elections.

Added Larry Sabato, a University of Virginia government professor who studies state voter patterns: "The big story of this election is the tremendous increase in the cost of politics."

"You see it all over the state, down in Virginia Beach, in Henrico County where they'll set an all-time spending record for the state Senate, up in Northern Virginia," Sabato said.

"It's gotten to the point where you have to spend $60,000 for a Senate seat and House seats are capping $35,000 or $40,000. Some of the numbers are incredible."

What is disturbing about this trend, Sabato and others say, is not only that considerable sums are being paid for offices that pay only $18,000, in the case of General Assembly seats, or $35,000 for Fairfax county board members.

As the cost of these races creeps ever skyward, some experts believe, fewer newcomers will dare run.

Nowhere is this more obvious than in the legislature, where roughly two out of every three members will have no opposition Tuesday.

"The irony is that it's happening at the very time we are trying to increase participation in the political process," said Lawrence H. Framme III, the state Democratic chairman. "People are being discouraged from getting into politics."

The news this fall is especially frustrating for the state Republican Party, which will be unable to break the Democratic control of the assembly in Richmond.

"We're very disappointed we didn't have more people running," said GOP spokesman Stephen D. Haner. "Some of our best candidates are in Northern Virginia, but they're running in the most Democratic districts in the history of Virginia."

Some other changes may be afoot, however. The elections hold the potential for sending a record number of women to the state Senate -- five, in the unlikely event they all win -- as well as a record number of blacks -- three -- to that chamber.

The question of whether Virginia should join Maryland and the District in the lottery business has sparked far less debate and controversy than most observers had expected.

The fate of the referendum probably is too close to call, although the momentum in recent weeks appears to have favored opponents of state-run gambling.

The latest poll, released today by the Richmond Times-Dispatch, shows the lottery favored by 58.2 percent to 34.9 percent, with 6.9 percent undecided.

The poll was conducted before Gov. Gerald L. Baliles announced Thursday that he will vote against the lottery, but 69 percent of the registered voters who participated in the poll said the governor's view would have no influence on their decision.

Lottery supporters, who have been outspent 2 to 1 by opponents, came up with $50,000 in additional contributions during the weekend to finance a get-out-the-vote effort.

Out-of-state companies that are would-be beneficiaries of a lottery provided all but $30,000 of the $230,000 raised by supporters.

The key to a number of races, not to mention the lottery referendum, will be the size of the voter turnout, according to political analysts.

If past four-year cycles are any indication, the turnout will be disappointingly small: Only about half of the 2.7 million Virginians who are eligible to vote will actually do so, experts say.

"It's hard for me to understand why people aren't more involved," said Fitz-Hugh, who has overseen four previous November elections from her office in Richmond. "If you asked the man on the street, half of them would not know or care the election is going on."

In Rappahannock County and some other rural parts of the state, voters will pencil in their choices on paper ballots, as they have for generations.

Fairfax County, with its array of election districts, will have no fewer than 67 ballot types, all on machine. And Fitz-Hugh, who hired four extra people to deal with the crush of candidacies this year, will be yearning for the far simpler presidential and congressional elections of 1988.

"That'll be a cinch," she said.