After Effi Barry erected a political poster for mayoral candidate Charlene Drew Jarvis on the Barry front lawn not long ago, supporters of rival candidate John Ray descended on the homes of Barry's neighbors and began erecting Ray posters on their lawns.

D.C. Council member Hilda H.M. Mason (Statehood), whose once secure at-large seat is being sought by Mayor Marion Barry, among others, has papered the city with more campaign posters than ever before, while council member John A. Wilson (D-Ward 2), a candidate for council chairman, has raised the strategic placement of yard posters to an art form.

Political posters have been stacked in totem pole fashion on traffic signs, utility poles and even trees. They have been taped to living room windows, glued to front doors and strung to automobile antennas as well as the sides and rears of Metro buses.

But while these posters and billboards certainly make for a more colorful campaign, just what purpose they serve remains a matter of debate.

"I have never seen a jump in the polls after a candidate's signs go up," said David Petz, a Washington-based political pollster. "But if a candidate doesn't use them, his supporters will have his telephone ringing off the hook, asking for their yard signs."

"If they didn't work, candidates wouldn't use them," said Mark Hayden, who produces political posters for many of the local candidates. "What posters offer is positive name recognition. In low-level campaigns, where the field is cluttered and the issues are muddled, a good poster is just the thing that a candidate needs."

Tom King, a Democratic political consultant, says posters are the mainstay of newly awakened political structures, such as the District's, creating for the candidate a perception of affluence, presence and support.

"It's old-style politics, what you might expect when people don't have a long history of political involvement," King said. "You revert to what everybody else has done in the past, which is why you see so many political posters in the new elections being held in Eastern Europe."

Among political operatives and volunteers, the war of the posters is a critical feature in each of the District's electoral contests. "It's like a canine marking territory," said one campaign worker. "They let us know where we've been, and it tells other candidates to beware."

Few believe that the posters actually translate into votes, but every candidate uses them.

"It's psychological warfare," said Mayor Barry, whose political machine studied the placement of rock band posters to develop its campaign poster strategy. "In the crucial battle for heavily traveled North Capitol Street, for example, you need to take Military Road south to Michigan Avenue. You have to get your posters up first, and you have to have them highest on the poles."

In the wake of his conviction on a drug possession charge, Barry said he had not yet decided exactly what his new posters would say. But one thing is certain: They won't be placed in predominantly white Ward 3. Relatively few posters have been, for that matter.

"I was told, even when I did have the support of Ward 3, 'Come and campaign, but leave your signs at home,' " Barry recalled. "They like polite, clean campaigns. Plus, they say campaign posters kill their trees."

Indeed, the two sections of the District where the poster war games are not played are Ward 3, the wealthiest, and Ward 8, the poorest. As for Ward 8, one political analyst put it quite bluntly, "They get neglected when it comes to everything."

Although it is a violation of D.C. litter law to mount posters on public property, the law appears to be ignored during elections. And, for the most part, District residents are tolerant -- unlike Virginian Roy Cole, who, two years ago, took a rusty machete and hacked down roadside campaign posters that he said "polluted the eyeballs."

Poster producer Hayden says the eyesore problem can be solved by using higher quality posters, meaning his six-ply, three-color, weather-resistant model that doesn't resemble a post office mug shot or "lost child" poster.

Hayden maintains that it is the amateurish cardboard posters, handmade in basement campaign offices, that crack, rip and -- like the candidates who can't afford to do better -- fade before Election Day.

Nevertheless, at a time when candidates are raising and spending millions of dollars on sophisticated polling and television and radio advertisements, it is still the relatively cheap, 14-by-22-inch, two-tone political poster that has helped create a lively mood in this city for Tuesday's primary election.