Journey's End, Courtyard Theatre London

A dugout on the front line during the First World War, the set of Journey's End is as sordid as many of the byways around King's Cross. But, with its glowing candles, copies of the Daily Graphic and Gothic-lettered prayer tacked to a bunk, it looks much more picturesque.

A dugout on the front line during the First World War, the set of Journey's End is as sordid as many of the byways around King's Cross. But, with its glowing candles, copies of the Daily Graphic and Gothic-lettered prayer tacked to a bunk, it looks much more picturesque.

If the stage looks like an exhibit, the play is something of a museum piece as well. RC Sherriff's 1928 drama woke the world up to the demoralising nature of trench warfare (you'd think the war itself would have done that) and became the progenitor of innumerable serious films, comic TV sketches, and Joan Littlewood's satiric musical, Oh, What a Lovely War!.

The officers, all decent, public-school chaps, have upper lips as stiff as their spines; their offstage commanders are batty but unfailingly obeyed; the one soldier who, nerves shattered, can't face enemy fire again is put right with an earnest pep talk. In Privates on Parade, written 50 years later, a character refers jokingly to the sort of drama in which a soldier says: "It's too quiet out there, I don't like it." This is where it was said first.

Shocking in its time for its naturalism, Journey's End today is rather risible, but also quite endearing, for its gentility. The men use no language their mothers couldn't hear, and never mention class hatred, gonorrhoea, rape and other aspects of foreign war and British everyday life. The most shocking line today is the captain's expression of contempt for a hearty type: "I suppose all his life Trotter'' – the fat one, of course – "feels like you and I do when we're drunk.''

Homoeroticism, camped up in parodies, is here a love whose name is softly whispered. The newest member of the outfit, just 18, has pulled strings to be with his boyhood idol (consider the title), and a former schoolmaster comments, twice, on his beauty. The most dated line in the piece is not one that includes the words "beastly'' or "topping'', but the solemnly delivered: "There's something deep, rather fine about hero-worship.''

It's a tribute to the quiet conviction of Richard Janes's production that a largely youthful audience raised hardly a giggle – a tribute also to its well-cast actors, whose appearance and bearing contribute to the sense of authenticity. As Captain Stanhope, Gregory Fox-Murphy has the razor cheekbones and languid charm of the high-strung thoroughbred, but is not brusquely vicious enough when reproving the would-be deserter.

Ben Elliot sweetly conveys eagerness and sturdy simplicity as the new boy – there's a nice moment when, keen to make a good impression on the colonel, he offers his hand too soon and has to withdraw it awkwardly, looking, in his embarrassment, even younger. Best of all is Robert Connor as the oldest member of the front-line club; his gentle, weary strength and quiet endurance poignantly convey the qualities of civilisation that are casualties of war.

To 27 Jan (020-7833 0876)