We've had a surge of fine new plays on Philadelphia stages in recent months, and some of the best are products of the same smart, cutting-edge program.

It's the National New Play Network's Rolling World Premiere initiative, which helps underwrite new plays to make sure they get at least three separate productions in three totally separate markets, all within 12 months — and all billed as world premieres as the play "rolls" cross-country to various theaters, casts, and settings.

Wait, you can't have more than one world premiere, can you?

Nan Barnett, executive director since 2013 of the network in Washington,  likes the conceit, as the same play will have such different lives: "The way it feels in a big theater in Philly will be totally different from smaller theaters in Denver or San Diego. It'll play differently in different-size houses, budgets, different communities."

Philadelphia has really benefited of late, with four Rolling World Premieres since January. The Arsonists by Jacqueline Goldfinger ran in May at the Azuka Theatre. Inquirer critic Toby Zinman called it "haunting, atmospheric," and "compelling." Karen Hartman's Project Dawn debuted in the spring at People's Light. I thought it was one of the year's best. And InterAct Theatre Company had an intriguing doubleheader in Will Snider's How to Use a Knife and Sean Christopher Lewis' Dogs of Rwanda.

The network consists of 30 core member theaters nationally (including InterAct) and 80 associate members (including People's Light, Azuka, and Theatre Exile). It's funded by a mix of foundation, corporation, and donor streams.

Each year, the initiative identifies at least three plays, and for each it gets at least three theaters in separate markets to do productions (defined as at least 12 performances) independently.  Each theater gets $7,500 to spend as it wishes on its production. Each production is billed as a "world premiere" to keep momentum rolling, encouraging further runs. This system has helped produce 75 plays since 2003. Works by 55 writers have played in 69 theaters, 52 cities, and 33 states for more than 240 total productions.

"It's really something," says Barnett, "when you can say 75 plays have been supported in this way, and that many go on to 10, 20, 40 more runs." A good example is the first beneficiary, the 2003 play Permanent Collection by Philly playwright Tom Gibbons. Inspired by the battle over Albert C. Barnes' will, it has enjoyed more than 45 productions. George Brant's 2012 play Grounded, another Rolling World Premiere alum, did a terrific 2016 turn at InterAct, the play's 46th go-round. In the spring, People's Light did Lauren Gunderson's I and You, now one of the most-produced new plays in the country. And the hits just keep on rolling.

Seth Rozin is a cofounder of the InterAct Theatre Company and a founding member of the New Play Network. "I say InterAct is my baby, and NNPN is my second child," he says. The problem the network was born to solve: Too many good new plays have had one run and died. "One city and never heard of again," as Rozin puts it. "For an extended life, you had somehow to get your play to New York for a commercial run and get great reviews. But at each turn, that's terribly hard and unlikely. There had to be a better way."

The network keeps its ear to the ground for good new plays in at least four ways. Members, of course, are always sending one another scripts. ("Theaters send me e-mails," Rozin says, "saying, 'I think I know a play that'd be great for InterAct.' ") The network has a monthly alert that goes out to every member company in which members pitch new plays. (Plays must be brought to the group by member theaters only.) Twice a year, there is a big network gathering to discuss promising titles, and there's an annual, three-day National Showcase of New Plays, at which six promising works get a reading.

"Once somebody says they're interested," Barnett says, "then we up the work on finding the other two partners. When we get the second one, then even more staff steps in to find a third or fourth or fifth."

Goldfinger calls the process phenomenal.  After its debut at Azuka, her play The Arsonists will have four more productions — and a theater in Denver, not part of the program, heard about it and will do the show after the last Rolling World Premiere, making six productions in  12 months. "I get to see my play in different theaters, all different sizes, from the Azuka to large regional theaters like Capital Stage in Sacramento," she says. "I get to see it scale up and scale down, how different actors play the roles, the different conceptions of stage designers. It makes for a much stronger play because you can investigate all these performance options."

She has been making changes all the way through, she says. "It opens my mind to the possibilities of what the play could be."

No Rolling World Premieres are scheduled at the moment for Philly, Rozin says — although a couple of plays slated for the spring may turn into rolling premieres between now and curtain.

The network also coordinates a searchable database of new plays, the New Play Exchange. Launched in 2015, it already has 13,500 plays and more than 5,000 users in 44 countries.

"The main thing we care about," Barnett says, "is communication between theaters and creators." That's how they roll.