“They were truly a random assortment,” said Todd London, the co-author of “Outrageous Fortune: The Life and Times of the New American Play,” a much-discussed book published in 2009. “In the meantime,” he added, “at least six or seven have become leading contemporary American playwrights.”

The 13 people who attended an initial meeting at the playwright Winter Miller’s apartment (two via phone) joined for various reasons. Some, like Ms. Ruhl, were deeply demoralized by the way many institutional theaters treated new scripts. At that time her drama “Eurydice” had racked up 13 readings and workshops without ever landing a production. Others wanted a sense of community. Others were flattered.

A few, like Anne Washburn and Lucy Thurber, had previous experience with theater collectives and doubted the experiment would last more than a year or two. Such skepticism may explain why Ms. Washburn requested the first slot, for a debut of “The Internationalist” in the basement of a theater in Greenwich Village in 2004. (Call it beginner’s luck; the play moved to the Vineyard Theater for a run two years later.)

But Rob Handel, who with Madeleine George first proposed 13P, had a day job fund-raising for the Mark Morris Dance Group. He felt confident he could collect sufficient donations and grants to stage everyone’s play over six or seven years. It took nine; he and volunteers raised enough to support productions that cost $30,000 to $40,000 apiece, as well as to cover minimal administrative costs.

Of course $40,000 doesn’t buy much theatrically, even downtown or in Brooklyn. It pays for space rental and actors’ salaries, but many designers donate their efforts, and the playwrights aren’t paid at all, nor do they take home a cut of the box office.