It was a "blue-sky session" in Hal Friedman's office at J. Walter Thompson. That means "there's no penalty for being silly or coming up with ideas that sound foolish," explains Friedman, senior vice president of the ad agency and creative director of the Burger King account.

So the four or five people in the room began playing with the temptation to ignore one of advertising's basic credos: Instead of pitching their campaign to everyone, what if they tried talking to an audience of one? An advertiser's dream, associate creative director Brian Sitts called it -- "everyone in the country knows and loves your product -- except one person."

And that person, why, he might be called, ummm, Mitch?

"Just didn't cut it," Friedman says.

Oscar?

"Two syllables," Sitts shakes his head. In a 30-second television spot, "you've got to save time."

Herb?

Clangggg. Time for the next round of what Madison Avenue calls the Battle of the Burgers.

Not everyone is coming out fighting. With 15 million customers a day and $9 billion in U.S. sales this year, McDonald's thinks it can afford to stay above the fray. The No. 1 burgermeister -- whose ads consistently decline to notice any competition -- introduced its new McD.L.T. last month with the usual musical extravaganzas and earnest discussion of packaging. "We've used a phrase around here for years," comments Paul Schrage, senior executive vice president of McDonald's. "Food, Folks and Fun."

"Singing and dancing about a new product is a time-honored technique," responds Sitts politely, trying not to smirk.

Because, really. JWT has the entire country -- the "creative" people in advertising are permitted to exaggerate for effect; it's part of the culture, like never wearing a tie unless you have to give a speech after work -- talking about the fictitious Herb. And a few blocks downtown, Wendy's agency -- Dancer Fitzgerald Sample -- is getting network news coverage for its Russian Fashion Show commercials.

DFS hasn't had this much attention since "Where's the beef?" Thompson hasn't gotten this much free publicity since McDonald's took it to court. Happy days are here again.

The Commerce Department says that fast-food sales increased less than 4 percent in the first nine months of l985, a dismaying performance for an industry accustomed to annual growth in double digits.

"The consumer is getting more and more finicky," says Rick Telberg, finance editor at Nation's Restaurant News. "To pull people into restaurants, you have to hit the boob tube."

Fast-food chains spend more on TV advertising than anyone except auto makers and brewers. Until recently, they favored footage of happy families devouring burgers, accompanied by happy jingles ("Who's Got the Best Darned Burger in the Whole Wide World?"). But the gloves came off in 1982.

Burger King happily takes credit for starting the Battle. Its taste-test campaign offered condolences to McDonald's and Wendy's because consumers allegedly preferred its burgers to theirs. McDonald's and Wendy's sued, the case was settled out of court and Burger King dropped the series. At J. Walter Thompson, people could hardly contain their glee. "Goliath versus David," Hal Friedman purrs. "Twenty to 30 million worth of free publicity, we figure. We enjoyed double-digit growth for 15 or 16 months."

So for season after season, Burger King's ads have named names, insisting that customers prefer broiling to frying and tracking how many burger lovers had switched from competitors. "All the time, it was working and working," Friedman says, recounting the Battle in the very Lexington Avenue office where Herb was born. Friedman is highly "creative" -- jeans, leather vest, boots, a 1972 haircut.

"It's good to be brash," chimes in Sitts, who's wearing a tie but only because he does have to give a speech after work. "It gets you noticed."

Still, "competitive advertising" has some drawbacks. After several years, "it wasn't outrageous anymore for us to name names," Sitts says, a trifle sadly. "It was just not novel," Friedman agrees. "We needed a new way to get people's eyes and ears."

They dreamed up the Herb campaign more than a year ago, but it was back-burnered by Burger King management. "There was just some nervousness about it," says Friedman. "They laughed and didn't know what to do with it and went on to something else" -- a retooled Whopper whose ads (starring Mr. T, Mr. Bill and the Three Stooges, among others) were popular but whose sales were disappointing. So when JWT reintroduced the Herb campaign ("We had never forgotten it," Friedman says with fervor), it got the go-ahead. It eventually cost $2 million to produce and $30 million to $35 million in media time.

Unsigned "teaser ads" began appearing in newspapers and on billboards across the country -- "It's not too late, Herb"; "What are you waiting for, Herb?" They were, Friedman says, "designed to raise Herb consciousness."

Meanwhile, at Dancer Fitzgerald Sample in the Chrysler Building, Bob Reed and Cliff Freeman, whose office is practically wallpapered with Clio award certificates, face some of the same problems. "We're outspent about five to one," points out Reed, who's DFS' executive vice president (identifiable by the tie as being on the "account" side). For the first half of the year, according to the Television Bureau of Advertising, McDonald's spent more than $143 million on TV spots, considerably more than Wendy's and Burger King combined. Being third in the pack, Reed notes, "You can't just come out with average advertising. We're always looking for the Holy Grail."

Wendy's found it last year with a series of funny spots poking fun at "some other hamburger places" where food was prepared earlier in the day or frozen, or customers had to "step aside" for special orders. The most famous of these, all directed by Joe Sedelmaier, was last year's where's-the-you-know-what. "Got Mondale the nomination, no question about it," says Freeman, who's senior vice president and (notice the sweater and red socks, no tie) creative director. It also increased Wendy's sales by 30 percent over six months.

DFS' latest venture, the subtitled, 60-second Russian Fashion Show, features narration by a hulking apparatchik while another hulking apparatchik models day wear (shapeless shift plus babushka), evening wear (shift, babushka and flashlight) and swim wear (shift, babushka and beach ball). The message? "Having No Choice Is No Fun," a poke at fast-food chains that don't offer fresh toppings, chili, baked potatoes and salads.

"A very, very funny commercial," concede JWT's Friedman and Sitts.

DFS was working on the fashion show long before the Geneva summit was announced, but the spot first aired directly afterward, prompting coverage by all three networks. "It's just been unbelievable, the number of people talking about it," Freeman beams.

Which was the point, right? "You bet your you-know-what," he says. "We're being so heavily outspent that we have to do advertising that people talk about."

But he's not buying arguments that the fashion show undermines peaceful coexistence. "I mean whoa, wait a minute. Forty years of cold war and someone thinks it's going to be affected by a TV commercial?"

Back at J. Walter Thompson, Herb teasers -- first unsigned, and then featuring Burger King's logo -- had yielded to a 60-second spot, aired 15 times nationally in two weeks. It introduced, with a Bach fanfare, the mysterious Herb, "the one man who has never tasted a Burger King burger." No one knows what he looks like -- in the only known photo, he's holding a bowling ball in front of his face.

Since the introductory spot, America has met Herb's parents (giving a press conference in front of a down-home-looking cottage that's actually in suburban Westchester, worrying that Herb's not normal) and his chums ("Herb was different"). His ruler-rapping old schoolteacher has reminisced about him and offered a lesson: "See Jane? See Jane smile? See Jane give her order for a flame-broiled Whopper? Sizzle, sizzle, sizzle . . . Run, Herbert, run."

The Herb campaign hardly scales new heights of hilarity, but it does what good advertising is supposed to do: grab viewers' attention. America has responded with letters and calls claiming to have sighted Herb. One man thought the unsigned newspaper teaser was a final warning from a loan shark. A woman in Pennsylvania called to advise that her neighbor was named Herbert Hamburger. And a Burger King in Minnetonka, Minn., got a letter from a Herb who said he was unable to taste a Burger King burger because he was doing time in the North Dakota State Penitentiary.

Friedman and Sitts, of course, are elated. One of JWT's informal bywords, Friedman says, is Hard Sell You Love to Watch. "It's easy to commit crimes on either part of that equation -- too much hard sell and people say 'Hey, it's only a hamburger'; too little and they'll remember the jokes and not the product." Herb, they think, avoids either trap. They are planning a celebration, with the six other core members of Burger King's creative team, at a Brooklyn steakhouse. "A big blowout," Friedman promises. "We'll all get stupid and ugly."

Next up? Six weeks is a long time in fast-food advertising; the Russian Fashion Show, the McD.L.T. introduction and the Herb spots will give way to new commercials next month.

McDonald's is sticking to Food, Folks and Fun with a campaign pushing hot food. Dancer Fitzgerald Sample will not discuss the next Wendy's campaign, except to hint of a major event toward summer, when Americans on the road eat even more fast food than usual.

J. Walter Thompson will concentrate on "deal advertising"; customers will get reduced-price cheeseburgers if they announce "I'm not Herb." Says Friedman: "It's sort of a game the consumer likes playing." And if a customer is named Herb? He can still get the deal by saying, "I'm not the Herb you're looking for."

Friedman will not discuss reports that the agency is auditioning actors to cast a real, live Herb. "We are considering," he muses. "There's an ongoing discussion" as to whether the mystery man will ever emerge from behind the bowling ball, march into his local Burger King and -- at long last -- order a flame-broiled Whopper (sizzle, sizzle, sizzle).

Personally, Friedman says, "I hope Herb comes in."