After almost 165 years' absence, eighteenth-century Britain has returned to Boston. The reigning monarch, Richard Brinsley Sheridan, now holds court at the Charles Playhouse, and his evening revels contain the funniest antics since George III went mad.

The Rivals recreates the England of 1775, complete with beautiful young ladies, their handsome and ardent lovers, and their meddling, if indulgent, parents. There's Miss Lydia Languish, an orphan of high birth determined to marry a soldier of low birth. And there's her lover, nobly-born Captain Jack Absolute, who must pretend he's a commoner to win Lydia's affections.

There's the Captain's father, Sir Anthony Absolute, a gouty tyrant who would make his son marry a one-eyed witch if the marriage portion were large enough. There's Jack's plegmatic friend, Faulkland, devoted to the beautiful Julia but always devising schemes to test her love. And there's Mrs. Malaprop, possessing a strong pretension for elegant loquation but always misconcerting her vocabularly.

Sheridan's characters are engagingly simply persons, each supplied with an appropriate flaw. They confide all their secrets to the audience, and they warn us that in their world deep thought is forbidden. They allow only hearty laughter.

The cast has as much fun playing these parts as the audience has watching them. Lynn Milgrim, a frequent visitor to the Harvard stage, lets her mobile face and huge eyes go wild. Her Lydia Languish pouts, purrs, and scolds with vivacious charm. Katherine Squire as Mrs. Malaprop declaims her ridiculous lines with such assurance and poise that they seem even more ridiculous. Earl Montgomery as Sir Anthony is a combination of Elliott Perkins and Nikita Khrushchev, polite and civilized one minute, stamping and roaring the next. As his son, the Captain, Richard Clarke views the behavior of Sir Anthony and Mrs. Malaprop with amused tolerance and woos Lydia with well-bred ardor. And Paul Schmidt, who has also appeared on the Loeb main stage, skillfully plays an affable yet irritatingly suspicious Faulkland.

Other deserve warm commendation: Jane Alexander as the affectionate Julia, Terrence Currier as Bob Acres, the country bumpkin, and George Mitchell as Sir Lucius O'Trigger, the aged but still hot-headed city rake. But the warmest praise must go to Michael Murray, the director. His lively pace piles absurdity upon hilarity, yet he never crowds his little stage. His conception of the play rests upon the humor in each character, not in the situation, and he presents them as individuals with exaggerated but endearing faults. They share the same manners and conventions, but they have clearly defined personalities.

Of course, The Rivals has the happiest of endings. Sheridan's people have no identity crises, are not neurotically repressed, suffer from no mal du siecle. They are amusing children skipping through a sophisticated world. And to a world-weary college student they are blissfully refreshing.