The Irish: poetic, hard-drinking, long-suffering victims of their chronically underclass society who, when they try to take aggressive action, often become authors of their own tragedies.

It's a familiar pattern, and one that local playwright Eric Lucas takes up in "The King of Mackie Street," one of three Irish-themed plays currently being presented by the Keegan Theatre. ("Mackie Street" is running in rep with Brian Friel's "Dancing at Lughnasa" at the Warehouse Theater on Seventh Street NW.) There is never any doubt that the title of Lucas's dark comedy is ironic, if not outright sarcastic. Lucas's characters have no money to speak of and nothing much to do. Boxed into a corner, the main character (a retiree whose pension is in jeopardy) tries to get money, which is when things go from wacky to grisly to maudlin.

As a writer, Lucas--an actor, director and associate artistic director with the Keegan Theatre--doesn't do anything in half measures. When he wants comedy, the characters drop their pants, wet their pants or bumble around in ropes and pantyhose masks as the most pathetic bunch of would-be thieves you've ever seen. When he wants drama, he delivers a senseless murder and brings a bloody baseball bat onto the stage.

That the play doesn't shift tones smoothly is partly the fault of director Daniel Lyons's too-boisterous production, and partly a matter of sheer overwriting. The play gets off to a promising start, with Francis McKeon (the title character) sitting in a stuffed chair in his modest living room, nursing a drink and scrutinizing the racing form with his old pal Dicky--an odd duck in a sports coat and boxing shorts who keeps his trousers folded neatly on a chair.

The meandering byplay is often funny as Francis (Robert Leembruggen) and Dicky (William R. Salisbury) talk about a whole lot of nothing (such as which Hollywood actors have "heat"), and occasionally about a little something (Francis's recent big loss at the track). Eamon (Geoff Wilner), the local policeman, drops in regularly to visit Francis's wife, Moya (Kathleen Fannon). Moya passes through the living room wordlessly every now and then, collecting cash she keeps hidden under knickknacks and behind Catholic icons.

Moya was originally Eamon's girl; it's a sore point between the men. Salient details like that get dropped in every so often, but the extremely long first scene gets draggy as Francis and Dicky begin to belabor their shtick (Francis as the hapless "king," Dicky as the dim sidekick). Lucas's quirky, interesting dialogue, full of cursing and complaining, begins to be predictable, and good gags quickly get overworked. Characters not only drop their pants but then have to bellow about it ad nauseam.

The effort lavished on repetitive comedy comes at the expense of fleshing out the characters in a way that would make the dark turn of events resonate. Dicky and Billy (Francis's incredibly incompetent, and incontinent, nephew) are borderline mental cases, while Moya isn't allowed to speak at all until the end of the play--and then she gets a long, predictable speech about the nature of love.

Leembruggen plays Francis with a morose, lost quality that keeps the character reasonably sympathetic, but the play's swing from low comedy to pointless tragedy is too wild and ungrounded for the gruesome turn of events to matter much.

The tale Lucas wants to tell--about lovable losers who overreach, desperately and poignantly--requires a delicate balance that isn't yet in the script, and certainly isn't in this broadly staged production.

The King of Mackie Street, by Eric Lucas. Directed by Daniel Lyons. Set designer, George Lucas; lights, Dan Martin; costumes, Pam McFarlane; sound, Tony Angelini; props, Rick Martin. With Daniel Sullivan. Through Feb. 1 at the Warehouse Theater, 1021 Seventh St. NW. Call 703-757-1180.

CAPTION: From left, Robert Leembruggen, Kathleen Fannon and William Salisbury in "The King of Mackie Street." Oddly, the play winds up overdressed.