The play begins at the country home of the Bliss family: Judith Bliss (a retired stage actress), her husband David (a writer of romance novels) and their two grown children Simon and Sorel. The room, says the stage directions, is very comfortable and very untidy. And so are the Blisses, we learn, for each of them has invited a guest (of the opposite sex!) for the weekend, but no one seems to have considered what they will all eat or where they will all sleep.

The idea for Hay Fever came during Noel Coward's first visit to New York in the early 1920s. Looking to find acting work and to shop his plays around (unsuccessfully, it turned out), he made friends and professional connections that proved very useful to him for many years to come. He was a regular guest at the home of Hartley Manners and his wife Laurette Taylor, the playwright and star respectively of one of the all-time great hits of the American stage, Peg o' My Heart (1912). In his memoir Present Indicative, Coward recalls having supper in their ramshackle home on Riverside Drive and playing games, "often acrimonious games," with the family engaging in "shrill arguments concerning rules". Added Coward: "It was inevitable that someone should eventually utilize portions of this eccentricity in a play, and I am only grateful to Fate that no guest of the Hartley Manners thought of writing Hay Fever before I did."

Rating: ***

Noel Coward's Hay Fever is little more than a running joke -- the bohemian Bliss family is too busy playing theatrics to be polite to the houseguests -- yet this 1925 comedy can easily sustain laughter for a full three acts.

That's what it is doing at the Shaw Festival these days, with artistic director Christopher Newton mounting another revival of the ever-popular play as his last act before retiring at the end of this season. On one of those jumbo country-house sets perfectly fashioned by designer William Schmuck, the cast offers a reliable version of Hay Fever that is long on laughs if occasionally short on explanations for the play's mismatched characters.

The action is anchored by Fiona Reid as Judith Bliss, the retired actress who is insufficiently occupied with the role of country lady and so takes out her desire for drama on the guests. She is nicely matched by Kevin Bundy, as the athletic young fan Judith has invited down for the weekend, hoping he will spend the time adoring her. She is shameless ego ill-disguised by fluttery poses; he is manly bravado giving way to gushing devotion, and as she descends into rudeness, hysteria and most of all fantasy, he becomes the very picture of middlebrow befuddlement.

It would be interesting to see what would happen if Reid raised the temperature by infusing a bit of her own real charm into a role she is so often asked to play, that of the aging beauty who merely thinks she is charming. Judith could only be more infuriating if occasionally you actually felt yourself falling for her.

Still, Reid's work in the parlour game in which Judith acts out the word "winsomely" is perfectly crafted comedy, as is Bundy's business with a faulty coffee urn: With this pair's broad reading of the roles, you always know where your are as the self-absorbed bohemians bump heads with the stolid middle classes. Similarly, Mike Shara's bumptious young Simon Bliss and Laurie Paton's brisk version of the experienced vamp who is his guest create another pair of clearly defined types in clear relation to each other.

But things get a bit muddy after that. As Judith's novelist husband David, Michael Ball gives us distracted remove -- and finally comic irascibility -- without revealing the self-absorption and sheer selfishness behind it. And if Lisa Norton is suitably dim and flustered as the young flapper he has invited down and then forgotten, it would be nice to see some tinge of the pertness or prettiness that occasioned the invitation in the first place.

The daughter of the house, Sorel, is the one Bliss with some awareness of her family's eccentricity, but Severn Thompson seems unsure how far to take that consciousness toward normality and winds up stuck somewhere between overeager nice girl and unrepentant bluestocking. She would be helped by a less improbable partner: David Schurmann is all very suave as the mature diplomat whom Sorel has invited down, but he is so much older than her and so staid in his romantic approaches that they barely register as such. His attempts at acting out the word "saucily" are equally far-fetched -- but this time to very funny effect.

These deficiencies in the performances are subtleties whose absence robs the audience of touchstones of character and class, the kind of easily readable work that Mary Haney is happily providing as Clara, the Cockney dresser who attempts to play the role of the Blisses' maid. But they certainly aren't crucial in an English setting that was actually inspired by the parties of a Broadway star and her playwright husband whom Coward met in New York.

It's a testament to the brilliant simplicity of the dramatic situation Coward invented here that, despite its now rather innocent version of sexual intrigue, its comedy remains enduringly foolproof. Newton argues, in his program notes, that for all its lightheartedness, the play is Coward's contribution to the theme of reality versus illusion, as the Blisses foist their exaggerated interpretations of the weekend's canoodling onto the guests.

It's a point that the director and lighting designer Alan Brodie make very nicely at the end of the second act as Judith and her offspring segue seamlessly from their overblown dispute about a party game into lines from one of her old plays. As the generalized glow gradually turns to the stagey side lighting and giant shadows of Victorian melodrama, there's double delight to be had in the theatrical tricks of the Bliss family on the one hand and of the Shaw family on the other.
Hay Fever runs at the Shaw Festival's Festival Theatre in Niagra-on-the-Lake until Nov. 24. For information: 1-800-511-7429.

Kate Taylor's reviews from the Shaw are available on-line at globeandmail.com