The Folger Theater Group and its audiences are surely most fortunate. In a building opened 45 years ago and containing the world's richest Shakespeare collection (while the Folger has, say, 79 First Folios, the British Museum has five), plays are given in a 214-seat theater, a room of scholarly authenticity intended to suggest the inn courtyard setting of Shakespeare's day.

Until eight years ago this two-level thrust stage could not be used for paying audiences because District fire regulations required more exit doors. By cutting down the original 262 seats this requirement was met by Folger Library director O.B. Hardison Jr. Previously only invitational audiences could attend such functions as lectures and concerts.

National television was on hand for a performance of "Julius Caesar" opening a week's stand March 28, 1949. Folger's then-director Louis B. Wright had arranged the performances because at that time the capital had no live theater. Equity having struck the National because of its discrimination policy. The players were the Masquers of Amherst College, whose trustees also are the Folger's.

Now the Folger Elizabethan theater area is a lively place through most of the year. While there are no performances from mid-July until mid-October, the staff always is working for the next nine-month season.

For the Folger group's eighth season and his own fifth as its director, Louis W. Scheeder has designed a season signaling the group's individual image, though Scheeder scorns "thinking in terms of a season."

Still, a season it is, especially when it comes to subscription sales. There will be two new plays and three by Shakespeare. Mondays will be opening nights, with reduced-priced previews starting the previous Wednesdays.

From London's experimental upstairs stage of the Royal Court will come the first offering, "Teeth 'n' Smiles," to run Oct. 12-Nov. 20. Introduced two years ago, David Hare's play depicts a rock band performing a one-night stand in June of '69. As the night wears on, alcohol and hashish paralyze the musicians. There is music by Nick and Tony Bicat.

Scheeder has described the play as being "about the incredible lack of order in the 1960s and what people will do to obtain structure in their lives." He will direct.

"The Two Gentlemen of Verona" will be the first of the three Shakespeares, playing Nov. 30 through Jan. 22. This comedy, also to be staged by Scheeder, will come to us in a pre-Raphaelite period. In this earliest romantic comedy, Scheeder declares, "you already can see all the germs of the later comedies."

Aware that Shakespeare is expected in the Folger Shakespeare Library (its official title), Scheeder has given some thought to how his limited resources can cope with such a challenge.

"If you're only going to do one Shakespeare a year, you're not going to do it very well," he maintains. "You've got to do him regularly. Most theaters have given up on the problem. We haven't. Say that one of our actors starts rehearsals on Nov. 1 for "Two Gentlemen of Verona." In mid-December rehearsals will begin for 'Hamlet' and by the time that's over, there'll only be a few weeks before 'Richard III' starts practicing."

The "Hamlet," running Feb. 1 through March 26, will be staged by the Folger's literary manager and music director, Jonathan Alper. This is an especially promising challenge, for two nights before Folger's "Hamlet" closes, Arena Stage will start previews for its first "Hamlet," to be directed by Romania's Liviu Ciulei, whose "The Lower Depths" was so impressive last season at Arena.

Ciulei, Arena's Zelda Fichandler reports, has a "a striking concept" for his "Hamlet," but does not elaborate. Alper is on record as planning to focus on the hero's "psychological intricacies as opposed to the political or melodramatic aspects of the play."

After this most demanding challenge of its eight-year activity, the group will turn to another new work, this one American. Scheeder is mulling several of these but doesn't want to make up his mind until a decision is unavoidable. Recent seasons have introduced "Creeps" and "The Collected Works of Billy the Kid," both Canadian, and "Medal of Honor Rag," "Mummer's End" and "Black Elk Speaks," all with American origins.

Finally will come "Richard III," to run May 24 through July 16. By the time the first two Shakespeares have run their course, its casting probably will fall into place.

Folger now is largely professional and a member of LORT, the League of Residential Theaters, of which Arena Stage was a co-founder.

Exactly how the Folger supports a professional company with only 214 seats per performance is an arcane miracle that defies easy explanation.

One clue can be obtained through two pages of its program for "A Midsummer Night's Dream," the group's most recent production. In boldface capital letters are these foundations:

The Morris and Gwendolyn Cafritz Foundation, Marcus and Harryette Cohn Foundation, D.C. Commission on the Arts and Humanities, the Ford Foundation, Eugene and Agnes E. Meyer Foundation, National Endowment for the Arts, the Shubert Foundation.

Then follow "backers," "sponsors," "donors," contributors" and a caution: "This year the American Shakespeare Festival in Stratford, Conn., and the D.C. Black Repertory closed their doors. These are but two of the recent professional theaters that have closed due to insufficient subsidy support."

Still keeping to last year's $18 to $26 scale for five productions, the Folger's miracle is that it finds non-box-office money to stay afloat. Apart from the tiny, exquisite and rarely used theater in the palace of Versailles, I suspect there is no other theater in the world with such intimacy for professional performances in so rich a building.

Small wonder its subscriptions are up to 5,800. This means that single performance tickets can get mighty scarce. One will welcome the day when Folger sells out however those unpredictable, irrational, insensitive curmudgeons the reviewers, react.