District of Columbia voters will go to the polls tomorrow to vote in presidential primary contests and to decide whether to legalize some forms of gambling in the city. Voters in some Virginia communities will decide a number of municipal races.

All registered District voters can cast ballots in tomorrow's primary election.

All voters will also receive ballots for the city's gambling referendum, an all-or-nothing proposal to legalize a numbers game and pari-mutuel betting on jai alai and dog racing.

Those registered as Democrats or Republicans will vote in their party contests for presidential preference, delegates to the national nominating conventions and local state committees.

The city's 137 polling placers will be open from 7 a.m. to 8 p.m., but persons in line at the precincts at 8 p.m. will be allowed to vote.

This primary is one of the most complicated in recent years, according to city election officials.

For the first time, Republicans and Democrats will have contests listed on both sides of the ballot instead of voting on only one side.

And Democrats will receive five ballots, which they must separate and deposit in two different ballot boxes as they leave the polls.

Republicans have a slighty easier time because they are not required to separate the four multicolored ballots they will receive. But they do have contests on both sides of some ballots.

For more information about District election procedures, residents should call the D.C. Board of Elections and Ethics at 347-9725.

In Northern Virginia communities which have elections on Tuesday, polling places will be open from 6 a.m. to 7 p.m.

Voters will decide both mayoral and city council contests in Fairfax City, Herndon, Clifton, Vienna, Manassas, Manassas Park and Leesburg; and will decide council seats in Falls Church.