SAN DIEGO, JAN. 29 -- The Super Bowl is the world's largest open bar, a strange, temporary universe in which it's not who you are, but what you get into.

It all starts at the corporate party village in what used to be the parking lot outside Jack Murphy Stadium. Now it is 400,000 square feet of party palaces, giant tents known as "chalets" where 25 major corporations will entertain 4,000 people Sunday, feeding them Norwegian salmon, roast sirloin and pieces of four-foot-high corporate logos molded in chocolate.

The largest tents, with room for 1,000 guests, have been rented by Ford Motor Co., ABC Sports and other car and hotel companies. The only Washington area company in the village is The Washington Post Co., which is entertaining its largest advertisers.

Inside the ABC tent, waitresses on roller skates will deliver fruit smoothies from a mock-up of a drive-in while guests mingle among a California set including catamarans and wind surfers.

And when it's all over on Monday, incredibly, it will continue, as the corporate village opens its doors to thousands of people who will line up simply to see where it all happened.

In the midst of a seven-day riot of partying, football seems a distinct subtext. The real event is what the sports writers call the Trough.

Consider, for example, Thursday night at Sea World. About 4,000 people, many of them ostensibly journalists, many locals and tourists who managed to snag passes, had the run of the theme park.

There were open bars at every turn, stocked with vintage wines and name-brand liquors. On the walkways between exhibits, hundreds of workers dished out gourmet dinners and presided over tables piled high with hors d'oeuvres.

Shamu the killer whale put on his show. And visitors were handed free baskets of dead smelt to feed the dolphins.

From early morning to early morning, the parties keep on keeping on:

At Crystal T's, a bar on Hotel Circle, where many Redskins fans are staying, one-time Redskin Ben Davidson spent the evening sitting in a corner, drinking beer and signing cards with his picture on them.

"Hey, Ben Davidson!" was the standard greeting.

"Hey, nice to see ya!" was Davidson's standard reply. Later, he said he loved the job, for which he is paid by the makers of Miller Lite. "It's always different," he said. "And you get to drink beer."

Barron Hilton of the hotel chain and Alex Spano, owner of the San Diego Chargers, are throwing a brunch Sunday for 1,200 of their dearest friends. Thursday night, Spano's party at the Marriott attracted Bob Hope and fallen TV commentator Jimmy (the Greek) Snyder, who was reportedly far from silenced by the bitter reaction to his odd racial theories, though he did arrive bearing letters of apology for people he may have offended.

Buick flew in its top dealers from around the country for a celebrity golf tournament, complete with a shrimp and steak bash at which they could meet Joe DiMaggio, Dick Butkus and Hal Linden.

The hottest invitation, as usual, is to NFL Commissioner Pete Rozelle's $750,000 bash at the Naval Air Station tonight. Not that Rozelle is offering a particularly spectacular spread. It's purely the exclusivity of the party that has everyone asking around for passes.

Indeed, the party fare is remarkably similar whether it's at the fancy Buick do in the oak-beamed ballroom of the Rancho Bernardo Inn or a simple media feed at the press hotel.

Lots of tiny egg rolls, the ever-present beds of shrimp and, for local color, a vat of guacamole. Ole'.

The key to getting into everything but the Rozelle gathering and the private corporate affairs is a simple little silver and blue pin distributed to accredited media folks.

Offers for those pins run up to $150, but there are few takers. The press is not known for its willingness to stray far from free chow.

And fans are quick to join the gravy train. John Perry, a physician who worked as the Redskins' team doctor in the '60s, collects the media pins and says he gets into "every party, every last one of them. It's the people, the scene, just marvelous."

Not every party requires a pass. Both Redskins and Broncos fans are holding pep rallies tonight.

And this evening's giant downtown fiesta put on by the city features 5,500 pounds of fireworks and a laser show billed as "light 1,000 times the intensity of the sun." President Reagan is providing the taped introduction.

Neil Scott-Barbour, president of Keith Prowse Hospitality USA, is betting millions that thousands of fans who have no intention of actually attending the game will nonetheless come to the stadium Sunday. There, they will pay the Prowse people $215 to sit in a tent furnished with chandeliers and artificial turf, sipping champagne and watching the Redskins and Broncos on large-screen TVs.

"They can stay from 11 to 11," Barbour said, standing in front of a sand sculpture of the San Diego skyline, packed from 300 tons of river sand. "The fans get a program, drinks and dessert. It should be quite the party."

The most extravagant event at the hospitality village is the Ford bash for 1,200 of its top dealers and customers. In addition to the pre- and postgame festivities, the company is throwing a Monday night gala culminating in fireworks and a top pop band.

"Take me to it, wherever the party is," said Lee Cunningham, a Redskins fan from Northeast Washington. "I have my burgundy jacket and bow tie. I am ready to party."

The local newspapers have trotted out the sociologists for the obligatory pregame comments about obscene excess. But it is awfully difficult to find anyone in San Diego who is offended by the celebration.

At Los Panchos Taco Stand, a 24-hour place on the seedy side of town, you can buy five tacos for $1.80. San Diego police officer D.A. Righthouse stopped in this afternoon to check the identification of several guys hanging out on the corner.

Jerome Cheatom pulled his papers out from his socks. Satisfied, the officer took off, leaving Cheatom to reflect on the Superhype in his hometown.

"I hear about those banquets," he said. "I saw one once when I worked at a hotel. They're nice. Everybody likes to party. You got any tickets to parties? How about a buck for a burrito?"