Fallout, Royal Court, London

Our monumental minimalist, Ultz, has created a set for Fallout that could serve as the backdrop for a present-day Greek tragedy. Dirty-white stone paves the floor and walls, except for two glass doors at the sides and a cave-like opening at the rear.

Downstage, a steep flight of steps spans the playing area, descending to regions unseen. But the drama, which periodically clutters this housing-estate bullring with plastic chairs (the set must serve not only as a courtyard but as a café and a police station) is far less impressive.

Matt, a white policeman, and Joe, his lower-ranking black partner, are trying to find out who killed Kwame, a boy bound for university who was envied by the local black ne'er-do-wells. Dwayne and Clinton, Perry and Emile, when not engaged in a little light purse-snatching, hang about the estate café, flirting with Emile's girl, a glamorous teenager with a name that sounds very much like a type of expensive lavatory paper.

Shanice, improbably young to be the cook/waitress of this establishment (which somehow manages to exist without owner or customers), is also attractive to another girl, Ronnie, who shoplifts sexy clothes for her.

The lesbian nature of Ronnie's attachment is never developed, though, nor is the more covert homosexual one between Emile and Dwayne. Ian Rickson's production is spirited and makes the most of its few jokes, but the acting ranges only from amateurish to adequate.

As it is obvious from the first who the killer is, Roy Williams's drama is not a whodunit; nor is it a thriller - to qualify for the term, a play needs to be at least slightly thrilling. Instead it is merely a waiting game.

Dialogue and characterisation are as thin as plot. No one is allowed even a momentary allusion to some memory or interest that has nothing to do with the murder inquiry, and the cast divide neatly into earnest and preachy (Joe and the white actors) or victims of society (the other blacks).

The two sides even speak different languages: Joe and the whites use conventional English; the rest, ghetto lingo (the text is even printed in it, as if "you", "where" and "some" are pronounced differently when spelt "yu", "ware" and "sum"), though I did catch one out in a subordinate clause.

The up-to-the-minute authenticity of this dialogue, while not compensating for its banality ("Shut up!" "You shut up!"), does highlight the triteness and contrivance of the story.

Why does the café conveniently empty when Shania wants to have a heart-to-heart with another character? Why does Joe try to suborn a witness who is plainly unreliable? Why does he do that in front of his superior, the straightest of straight arrows? Throughout the long, discouraging investigation, nobody seems to have heard of DNA.

Plays such as Fallout are praised frequently on the ground that they bring young, non-white patrons into the theatre. But if all the theatre does is reproduce their milieu (and where, by the way, are the plays about middle-class and respectable poor black people?), bringing to it no more insight or beauty than television can, why should they return?

When an audience is too unsophisticated to hoot or groan at such lines as, "Why should people care about you lot when you don't even care about yourselves?", the chief beneficiary is the playwright.

To 12 July (020-7565 5000)