Too often when a good book or play becomes a movie, the script writers fail to see that they have good things in front of their noses; passionate (and pointless) adaptation turned such solid novels as Exodus and Advise and Consent into mediocre cinema. Fortunately, the men who took Gore Vidal's recent hit play The Best Man and made it into a movie had the sense to leave well enough alone. As a result, they have put together a terrific film.

In Hollywood, "adaptation" usually means adding excitement and sex. Gore Vidal's story of a contest for the presidential nomination at a national political convention had plenty of excitement to begin with and sufficient sex to keep the plot thickened during all of the balloting. The contestants are easily recognized types, obviously modeled on contemporary political figures. Russell (Henry Fonda) is a Harvard man, an intellectual, and Secretary of State. Unlike most people around him he has principles: he wants to wage a scrupulously honest campaign for the nomination.

But Cantwell (Cliff Robertson), Russell's opponent, plays dirty, and most of the film concerns Russell's attempt to decide whether he should use Cantwell's own methods to fight back. The personal battle is played against the noise and glitter of a wide-open convention, done up for the screen with superb realism.

What makes The Best Man so good is the professional tone maintained in all of the photography, direction, sets, and, especially, the acting. Margaret Leighton as Russell's wife and Shelly Berman as an old army pal of Cant-well give brilliant performances along with Lee Tracy, in his recreaton of his Broadway role of the dying, crusty ex-President whose endorsement is sought by both candidates.

In short, The Best Man is the best bet for exam period escape.