The Maryland General Assembly opened its 202nd annual session here today under the cloud of the state's protracted savings and loan crisis, a financial disaster that legislative leaders said could threaten their full agenda of social, educational and other government programs for 1986.

As more than 200 savings and loan depositors staged a caustic protest in the frigid air outside the State House, members of the state Senate and House of Delegates held largely ceremonial elections of presiding officers and heard mixed reports about the impact of the S&L crisis on legislative initiatives in the 90-day session.

"All of us have been in the cold for eight months, so why should today be any different?" bellowed David Zinner, who led the two-hour protest that was designed to draw attention to the 100,000 thrift customers with virtually no access to their $1.2 billion in deposits. Their signs directed some of their most bitter invective yet at Gov. Harry Hughes, including one that read, "Heave-Ho Harry-O, Out of Politics You Go."

The protest featured a fiery, extemporaneous speech by consumer advocate Ralph Nader who advised the demonstrators to lobby for the formation of a consumer watchdog group to monitor financial institutions in the state. Depositors sang songs and lampooned Hughes for his failure to issue a comprehensive plan to return money to depositors whose funds are frozen.

One song, to the tune of "Take Me Out to the Ballgame," chided Hughes for avoiding a confrontation with the depositors in a recent fund-raiser held to support his aspirations to a U.S. Senate seat:

"Take me out the back door please. Get me far from the crowd. I'm a bit slow to get the right track. So what if it's years till your money is back?"

The state has been embroiled in the thrift crisis since last May, when runs began at several privately insured savings and loans that were loosely regulated by the state. The runs prompted Hughes to freeze withdrawals at all of the thrifts as the state tried to sort out the problems and move the thrifts into a federal insurance program. The state now controls four of the most troubled thrifts.

Meanwhile today, the 187 lawmakers convening their 90-day session tried hard to maintain the traditional aura of good cheer and optimism that accompanies opening day. But beneath the pleasantries was unease and dissatisfaction that was only slightly more subdued than that of the depositors outside.

Many lawmakers complained that Hughes' failure to meet self-imposed deadlines for a relief plan could place them all in political jeopardy, especially in an election year that is expected to produce a dramatic reshuffling of the state's top political leadership.

"There's a lot of frustration and anxiety," said Del. Mary Boergers (D-Montgomery). "It just seems to me we ought to be doing more. The fact is, we're being held politically accountable. We've done everything we've been asked to do and it still isn't resolved. We're hanging out there with the governor. I don't mind hanging out if there's something I can do, but when there's nothing on the table to consider . . . . "

In their opening remarks and interviews, House Speaker Benjamin Cardin (D-Baltimore) and Senate President Melvin Steinberg (D-Baltimore County) reiterated their earlier pledges to offer their own plans for resolving the crisis if Hughes does not make public his blueprint soon. Hughes is scheduled to make a five-minute television address Thursday night and to review his progress with the General Assembly in a speech Friday morning.

"We are prepared to act, whether he [the governor] has a plan or not," said Cardin. Although the lawmakers set no deadline for Hughes, Cardin said, "we have 90 days and we're going to take action as soon as we can."

One key point of contention between the governor and the legislature, said legislative sources, is whether to raise money to pay back depositors by selling off the assets of Old Court Savings & Loan, as the administration prefers, or to use state funds first and hold onto the assets in the hope that the state will receive a better price in the future.

Nader told depositors the state should float bonds to pay depositors with interest immediately, liquidate the troubled thrifts, then retire the bonds on the proceeds of the liquidation.

Another key issue is how to pay for the multimillion dollar reserve fund requested by the agencies that evaluate the state's creditworthiness. Hughes aides said today that the administration will propose to borrow $100 million out of the state's transportation trust fund.

Despite all the emphasis on savings and loans, both Cardin and Steinberg cautioned their members not to allow the thrift crisis to obscure other issues before the Assembly this year, including escalating commercial insurance costs and an array of social concerns such as teen-age pregnancy, housing for the poor and juvenile services.

Cardin, a candidate for Congress who will serve his last term as speaker this year, was generally optimistic that all the legislature's goals could be accomplished. Although "we don't know how expensive the resolution of this problem will be . . . ," he said, "fortunately revenue growth this year will be adequate to establish these reserves without jeopardizing funding for services needed by the people of this state."

But others, particularly in the Senate, were not so sure. "It's not going to be a pleasant session," said Sen. Laurence Levitan (D-Montgomery). "We don't have any money to play with."