Broadway's striking new version of an Ibsen classic; Ghosts Play by Henrik Ibsen. Adaptaption by Arthur Kopit. Starring Liv Ullmann, John Neville, Edward Binns. Directed by Mr. Neville.

A touch of autumn has come early to Broadway this year. And so has the season's first serious drama, a new adaptation of Henrik Ibsen's ''Ghosts.'' Both the weather and the production have proved bracing.

At the Brooks Atkinson Theater, Norwegian star Liv Ullmann is giving a burnished performance as Helen Alving, sometimes described as Nora of ''A Doll's House'' 20 years later. The staging credited to John Neville is a model of clarity, intellectual vigor, and emotional force, with the ironies duly observed.

Once misread as a drama about the sins of the fathers being visited on the children, ''Ghosts'' has come to be recognized for its much larger dimensions as a study of the devastation caused by false idealism and false pretenses. As Michael Meyer, an Ibsen authority, has written, the play's subject is ''the devitalizing effect of a dull acceptance of convention.''

Ibsen expresses the enveloping hauntedness of the tragedy in the explanation Mrs. Alving gives to the unctuous Pastor Manders. She says she is ''half inclined to think we are all ghosts . . . not only what we have inherited from our fathers and mothers that exists in us, but all sorts of old dead ideas, and all kinds of old dead beliefs and the like.''

Widow Alving's ordeal has been the long struggle to shed such dead ideas and beliefs, and to reach the high ground of a truth she can live with. Her conclusions outrage Manders, just as the appearance of ''Ghosts'' in 1881 outraged the public of its day, including a good many free-thinking liberals. One of the genuine strengths of Miss Ullmann's portrayal is that she keeps reminding the spectator of the ordeal Helen Alving has endured to reach the point of being able to challenge the shibboleths cherished by Manders.

As Miss Ullmann plays her, Mrs. Alving has achieved astuteness without losing humanity. She is not fooled - as Manders is - by the shallow pretenses of the rascally Engstrand (Edward Binns). With good reason she senses the dangers posed by the presence of Regina Engstrand (Jane Murray), the Alvings' pert and personable young housemaid. Mrs. Alving can attack Manders with her acquired unorthodoxies and yet impulsively relent in perceiving ''the great baby'' that he is.

Miss Ullmann conveys the deep maternalism of a mother long separated from her son. The actress also registers the compassion with which Mrs. Alving recognizes how her young husband (whom ''it was a holiday just to look at'') could have been driven by a joyless marriage and suffocating provincialism into a life of dissipation.

Mr. Neville's Manders is very much the earnest zealot, the respecter of respectability, tilting at life with platitudes. The Neville parson is insufferable but not detestable, ludicrously pompous and quite unaware of his pomposity. He is a gullible dupe in the hands of Mr. Binns's slyly mendacious Engstrand. Yet there is also in this handsome clergyman an unseemly readiness to grasp at Engstrand's offer of testimony that will clear Manders of any blame for the fire that destroyed the orphanage intended as a memorial to Captain Alving.

Kevin Spacey gives an unusually effective performance as the doomed Oswald Alving. He and Miss Ullmann fulfill all the demands of the emotionally shattering final scene. The handsome Miss Murray seems almost too 20th-century for a maid in a 19th-century Norwegian fjordside town - even for a Regina with her eye on the main chance. But this approach may be attributable to direction.

Arthur Kopit's adaptation seems to follow - with its own variations - the more familiar translations of ''Ghosts.'' It is fluent without committing anachronisms. Kevin Kupnik has designed an airy and cheerful living room, a relieving contrast to the symbolic surrounding gloom of the landscape. Theoni V. Aldredge's costumes - including a muted red gown for Miss Ullmann - and Martin Aronstein's lighting enhance a production whose mixture of accents does not detract from its impressive power.

''Ghosts'' is scheduled to remain at the Brooks Atkinson until Oct. 2. It will begin touring in Philadelphia (Oct. 25 -Nov. 13), and will also visit Chicago (Nov. 15-Dec. 11), Denver (Dec. 13-18), San Diego (Dec.20-26), and Los Angeles (Dec. 27-Jan. 22, 1983).