"Write from what you know" is the conventional wisdom spouted to neophyte writers. And with her first play, "Bumps," actress Caron Tate has followed the maxim to the letter. While finding her way as a black actress in Washington's small theaters, Tate supported herself by dancing topless and nude in clubs, and it's her energy and conviction alone that keeps the wildly uneven "Bumps" from becoming a grind.

Though it's grounded in actual experience, "Bumps" is not autobiographical. Tate has sketched a typical club dancer, far removed from her own personality. When naive, uneducated Sylvia stumbles into the club and removes her shirt for the first time, a patron grumbles, "Welcome to the little town of go-go." And it is a world unto itself, with familiar patrons, a sort of sisterhood among the dancers -- and no taxes.

Tate actually makes the job seem kind of cozy for a while, as Sylky gets good advice from fellow dancers and emerges looking like a demimonde Diana Ross when she moves up to the swankier clubs around Dupont Circle. Sylky meets Joe, a nice guy willing to overlook her occupation at first. But by the time he gets fed up, it's too late anyway -- Sylky's hooked on the illusory love and admiration, not to mention the cash, that only clubs can give her.

Though Tate makes it clear it's not a wonderful life, she avoids the obvious pitfalls of titillating the audience or moralizing at them. But the actress is untrained as a writer, and while it's clear she knows the territory and what she wants to show us, her script loses its shape and gets seriously flabby in the last hour. She has a degree of insight into the dancers and the men who patronize them, but makes a mistake in trying to cram everything about a dancer's existence into one play.

Tate is a charming actress, and her Sylky is a convincing combination of tough tart and tender victim; she handles the seminude dancing without a trace of discomfort. Cornell Hills is an attractive and steady presence as Joe, the guy who gets to Sylky's cash-callosed heart of gold. The play is fleshed out with a cast of 18, and while it's clear most of them are first-timers, all the performers attack their roles with energy. Tate and director Ed Bishop pack the stage with so many things at once that, whether by accident or design, they achieve a realistic, occasionally almost anarchic atmosphere. This is as close to the real thing as one could hope for (or fear) in a theater.

"Bumps" is being performed at the Back Alley Theatre, which has been vacant for 10 years. It's a basement room with problematic sightlines -- several substantial pillars block the view in spots -- but the underground place feels somehow appropriate to the subject and the thump of disco music, and the rudimentary lighting, heavy on the reds and blues, evoke the dim, seedy air of the nightclubs.

Bumps, by Caron Tate. Directed by Ed Bishop; lighting, Ed Bishop and Steve Lombardi. With Robert J. Allen, Donna Barrett, Landon Bernard, L. Belton, Matthew Allen Bretz, Robert Brown, Edie Catto-Kopp, Carter Cochran, Cornell Hills, Joy Johnson, Logan Johnson Jr., Moire MacDonald, Rosina Mason, S. Robert Morgan, Cathy Simpson. At the Back Alley Theatre, 1365 Kennedy St. NW, through December.