"The Winter's Tale" is not exactly a good play, but it is a wonderful one. Among Shakespeare's works, it has some affinities to "King Lear," for it is a study of royal madness, and to "The Tempest," for it is about young love and strange happenings. Comic and tragic moods mingle and clash often in Shakespeare's work, but nowhere more jarringly than in this one. The plot is a jerry-built structure of improbabilities and coups de theatre , its characters are most powerful when they are most one-dimensional, and they are manipulated shamelessly by a playwright clearly out to make a fast buck and draw easy applause from a mass audience. A PBS production of the play will be broadcast on WETA-TV, Channel 26, at 8 tonight.

The placing of one of its scenes on a seacoast in Bohemia (which has no seacoasts) has became a proverbial token of Shakespearean carelessness. On that nonexistent seacoast, Shakespeare gives the most striking state directions in his entire work: "Exit pursued by a Beare." This is a bear ex machina ; the creature has not been mentioned previously in the play but is brought on when the playwright wants to get rid of a character quickly and give the audience a cheap thrill. There are plenty of these moments. The final act, in which a statue comes to life, is as melodramatic and unbelievable as the first, in which groundless jealousy is raised to the level of pure paranoia.

With all its faults, the play is beautifully written. Its central characters are both unreal and stereotyped, but its poetry strikes to the heart repeatedly and unexpectedly. No doubt, some poeple can see "The Winter's Tale" and not care about the improbable fates of King Leontes of Sicily, his disastrously misunderstood wife Hermione, who is a daughter of the emperor of Russia, and his long-lost daughter Perdita -- who is left in a wilderness to die but found and raised by an old sheperd, until Prince Florizel falls in love with her, not knowing that she is a princess. This attitude is correct, perhaps, and shows a well-developed sense of dramatic propriety. But objections are reduced to dust by the magic of the English language in the hands of its supreme master.

In the PBS production, the essential unreality of the play has been warmly embraced. It is played on scanty, semi-abstract scenery, appropriate for a story whose true location is never-never land, and the cameras spend little of their time on background and much on close-ups -- a device that Shakespeare would surely have loved. The direction of the play is thoughtful, the acting generally good. Particularly notable in a fine cast are Jeremy Kemp, who makes the madness of Leontes believable, Margaret Tyzack in the secondary but vital role of Paulina, and Rikki Fulton playing the rogue Autolycus.