It took almost 2 1/2 hours of play and an instant replay, no less, before it became painfully clear yesterday that Wheaton, Md.'s Dana Terman had not quite achieved his goal: the world championship of Monopoly.

But Terman, a 24-year-old car salesman and U.S. Monopoly champion, keeps getting closer. In his last world tournament, November 1977 in Monte Carlo, he came in sixth. This time he was runner-up to Cesare Bernabei, a 28-year-old electronics engineer from Rome.

Eighteen champions from around the world had been flown in by Parker Brothers for what was billed as "the greatest gathering of international Monopoly champions the world has ever seen." The South African national champion was to have participated, but the Bermuda government refused to let him play as a protest against the South African apartheid policy.

The instant replay of the championship match's last play, from a closed-circuit taping of the final match, was used to determine wether or not Terman had in fact landed on one of Bernabei's hotels. Someone thought Terman might have miscounted his move, but he hadn't. He has thrown an 11 from "Go" to St. Charles Place and gone bankrupt.

Millions of play dollars changed hands in 48 hours as hundreds of spectators at the Southampton Princess Hotel on the Atlantic passed up golf, tennis or the sun to stand around indoors and watch Monopoly as most had never seen it played. This, if you will, is quite different from the kitchen table variety.

As Terman puts it: "There's a different mental approach to the game. Tournament Monopoly is very serious Monopoly. I've studied the game. I've read all the books. I've memorized all the odds and spent time practicing different strategies."

Terman came into the championship with an increasing reputation, having dispatched Angelo Repole last November in New York to retain the U.S. title. (Repole, 10 years old, was the youngest finalist ever in the U.S. Monopoly championships and retired to the men's room in tears.)

When some of the hotel guests and visitors heard the fourth International Monopoly World Championships were scheduled, they shook their heads. "World championship what? . . . You mean that game we played as kids?"

Some of the players, quite serious, passed on such advice as "The trick to the game is to make the right trades" and "Keep your opponents from getting properties even if it means mortgaging your own" and "The utilities are the worst properties on the board."

Executives from Bermuda's M. T. Butterfield Bank handled money and property chores. Four preliminary rounds ensued and when the "Take-a-Ride-on-the-Reading" smoke had cleared, Terman was one of five finalists, along with Italy's Bernabei and experts from Switzerland, France and Australia.

At Monte Carlo, Terman carried in his shirt pocket a wishbone that his mother had painted red. He did not make it to the finals. Again, this time, he was accompanied by his parents, Frederick and Gladys Terman, but this time he did not carry his red-painted wishbone.

At first his luck seemed good. He took an early lead in the five-player final and forced two players out of the game, first Australia, then France, Terman amassed the Boardwalk-Park Place monopoly, plus a number of other properties.

But the Italian then accumulated a large amount of cash and invested in hotels on the two least expensive properties, Baltic and Mediterranean. Terman faded; he had property, but only $2 in cash at one point.

The Swiss player was next to go. He went bankrupt to the Italian and it wasn't long before Terman rolled his fateful 11 from "Go."

About 400 persons jammed into the smoke-filled room to watch; they sighed, applauded and gave advice, following each move as if all the money and property were real.

For the participants, they were. At the end, Terman managed to say, "The best player won." A relieved Bernabei, who recently took a job with a Princeton, N.J., electronics firm said, "I never thought I'd lose as much weight playing a game of Monopoly."