If you go to see Hedda Gabler in London and then Hedda Gabler in Chichester some things will give you a sense of deja vu. But not much.You'll see two acclaimed actresses in the title role, each one maliciously mistaking the aunt's brand-new feathered hat as belonging to the maid, each one vengefully burning Eilert Lovborg's manuscript in the drawing-room stove and (when the time comes) each one going behind the curtains with one of her father's pistols and blowing her brains out. In other respects you could be watching two different plays.

It's chastening to see how little control a playwright has in determining the outcome of what he or she writes. Helen Cooper has "adapted" the Chichester version and Kenneth McLeish has done a "new translation" for the English Touring Company, but the real adapting and translating occurred in rehearsals. The two actresses, Harriet Walter and Alexandra Gilbreath, take the same facts - 29-year-old general's daughter returns from a six- month honeymoon with dull, scholarly husband only to shoot herself two days later - and, guided by their directors (Lindy Davies and Stephen Unwin, respectively), they construct wildly diverging subtexts.

At Chichester Harriet Walter mines the tense ambiguities of an independent woman ensnared in a dependent situation. Walter reclines imperiously on the sofa, queries remarks with a nervily poised, ironic tone and impatiently swishes her gown as she paces the carpet. She builds a frightening portrait of a woman torn between social convention and despair. Watch her wide mouth as she struggles to hold a frozen smile: it's a study in concealment and revelation.

Harriet Walter's Hedda shifts between languor and recklessness: she can spend the whole afternoon dressing for dinner or amuse herself by firing shots at Judge Brack as he approaches the house. She is pregnant and when there is no one else in the room Walter clenches her fists in the air and pummels her stomach. Walter holds our sympathy, despite her cruelty and self-absorption, because she recognises that she has built this prison for herself. She is a victim of her own cowardice.This contrasts with Mrs Elvsted, played with an attractive decisiveness by Jenny Quayle, who has left her husband.

Walter's cool sensuality and the tantalising effect it has on others dominates Lindy Davies's richly atmospheric, erotically charged production. Already bored with Tesman, her husband, played by Nicholas Le Prevost as a hesitant, stuttering, near-farcical figure, Harriet Walter flirts with Judge Brack, intriguingly interpreted by Peter Blythe as a smooth, quietly spoken professional figure whose predatory lawyer's instinct detects a situation he can exploit. Walter flirts dangerously, too, with the author Lovborg, sharply characterised by David Threlfall as a sallow, wild-haired figure who retains the defiant, deliberate air of the self-possessed intellectual. None of these relationships can work. Harriet Walter's death, when it comes, has a powerful inevitability.

Alexandra Gilbreath, Hedda Gabler for the English Touring Company, takes the opposite approach. Her Hedda declares herself at once. She's a nightmare from the word go. What tension there is exists between Hedda and the other characters and not within Hedda herself. The younger of the two actresses, Gilbreath may be the right age to play Hedda but her idiosyncratic performance never capitalises on this sense of thwarted youth. She's a taunting, steely figure with a sarcastic mind and an undisguised contempt for her husband. Gilbreath has played Regan opposite Warren Mitchell's King Lear at the West Yorkshire Playhouse and - judging from her performance as Hedda - she's clearly marked out to play a highly effective Lady Macbeth.

She holds her chin up high, and employs a husky forcefulness that Mrs Thatcher would recognise. As she patrols the stage, she tunes in and out of the conversation with a harsh disregard. It makes the marriage look more implausible than ever. Crispin Letts runs round his wife with a puppy- like devotion, Jonathan Phillips makes a weirdly sonorous Lovborg, and Carol Starks's bland Mrs Elvsted left me thinking that the deserted Mr Elvsted has no cause to complain.

In Stephen Unwin's production the performances are clear, competent and careful, but they are also flat and dull. The Tesman household is devoid of atmosphere. Nothing seems to be going on except the exchanging of lines. The difference between the two Hedda Gablers can be seen in purely physical terms. In Unwin's production, Lovborg's brilliant manuscript about the future of civilisation appears in a scruffy envelope. In Davies's production the manuscript is placed in a package on the floor, the brown wrapping- paper is carefully unfolded, the pink ribbons that hold the papers together are untied and the carefully printed sections of the book are lovingly spread out. Far more than a prop, the manuscript becomes an event. Later, when Harriet Walter destroys it, claiming that she is destroying a baby, the words are not cheap.

The story of The Fantasticks, a musical by Harvey Schmidt and Tom Jones, turns out to be as fantastical as the plotline itself. Adapted from Edmond Rostand's play Les Romanesques (1894), this comic story about two neighbours who pretend to hate each other so that their son and daughter will fall in love opened in New York in 1960 and is still running.

In Dan Crawford's lacklustre production at the King's Head it is impossible to see why. A film version has also been made, starring the British actor Jonathon Morris (best known from Bread) in the role of swashbuckling narrator El Gallo. In an admirable piece of cross-fertilisation (Hollywood one day, fringe the next), Morris also plays El Gallo at the King's Head.

Crawford has switched the action to Yorkshire in an effort to ground this piece of end-of-term entertainment, but he would have had to sign up Geoffrey Boycott and Brian Close as the fathers, to get away from its cloying archness. Morris has some of the gleaming sincerity of Sir Cliff Richard. He teases the audience that he is going to need some more actors. For once it seemed like a good idea.

Theatre details: Going Out, page 10.