BACK IN THE old days, when interhouse was interdicted, the rules made good old sense. No one on campus could eat at anyone else's House unless they were invited, visitors were put on a guest list and had to be sponsored to sit down. Rigid, but civilized.

But the 1980s have brought a more liberal regime, a reliance on market forces to regulate supply and demand, and, not surprisingly, the rise of protectionism. The intolerance war is on.

"Interhouse rules are set by each House, that's about it," says Director of Food Services Frank E. Weissbecker, bluntly defining the new gastronomic Darwinism. Central planning dictates that breakfasts are unrestricted across campus, and steak nights are always restricted, but after that you're on your own.

In Kirkland House, Wednesdays are off-limits; at Lowell, disdain Friday lunches after 12:30; at Elliot, don't come for dinner after 6:15; at Kirkland and Leverett, starve after 6:30.

"Each house is unique," says Adams House manager Paul DuFour.

Masters and the House Committees call the shots in the 13 fiefdoms. Lowell's Fridays, for example, are restricted because of the Senior Common Room's weekly luncheon, while Quincy's Wednesday Master's Sherry is a cause for barriers to entry at that House.

And the battles rage on. Lowell House Committee established its own Monroe Doctrine during the recent opera, and action which brought down heavy crossfire on innocent Lowell House checker, Winnifred Linnane. Usually in favor of interhouse, Linnane had to bear the brunt of the ruling: "they think it's me," she protests, "but it's you kids."

Nina Kuntsly, head of the Lowell House Committee, recently proposed dropping all barriers as an example, and recently convinced the Master to buy extra tables to end no interhouse.

But across the board accords remain elusive. Quincy manager Joe Micucci briskly calls out that house's rule: "50 the first hour, 50 the second," "go look at Adams," he adds.

A FIRST testing of the notoriously xenophobic Adams House waters brings little response, where, it seems, the question has been asked before. But Mr. DuFour is non-plussed by the notorious Adams rule--which still requires dinner sponsors. He points to the proximity of the House to the Yard and the native popularity of its smaller dining hall.

Asked if the House's dining policy has been a bone of contention, DuFour shrugs, "not to my knowledge." Ann Sicari, manager of the Quad dining halls, even eggs him on; "I wish they'd throw them out more," she says, adding "then they might come back up here." The Quad's policy, says Sicari, is generally open, save during reading periods, when Hilles attendance overwhelms.

Kirkland raises the drawbridge nightly--at 6:30 when roaming athletes return from the athletic area to forage for food.

The well-muscled too fall victim to the exclusionary rules, quick to turn away the many yearning to eat free. For if beneficence is paramount before 6:15, afterwards, the Houses themselves are yearning to be Adams.