Here are two nuggets of conventional Broadway wisdom: The new play is dying. And when it’s not, the Brits usually steal the spotlight.

But this year’s Tony nominations for new plays are flouting those preconceived notions. The all-American crop, from four playwrights making their Broadway debuts, speaks to the growing health of the new American play — and the increasing number of producers willing to take commercial risks on untested titles.

The Americans making their Broadway debuts in the new play race are hardly unheard of — especially Lynn Nottage, who has two Pulitzer prizes to her name including one for Tony nominee “Sweat,” and Paula Vogel (“Indecent”), who’s got her own Pulitzer on the mantle. Both J.T. Rogers (“Oslo”) and Lucas Hnath (“A Doll’s House, Part 2”) also arrive after turning heads with Off Broadway work.

None of these shows have big, bankable names in the cast along the lines of Hugh Jackman or Denzel Washington. The highest profile of the actors in the bunch, Laurie Metcalf and Chris Cooper of “Doll’s House,” are certainly recognizable but haven’t inspired a box office stampede.

But even if an unfamiliar title and the lack of big star can make for a rough commercial road, producers in recent seasons have begun to make it work. The New York outpost of London hit “The Curious Incident of the Dog in the Night-Time” managed to carve out a relatively long life for itself even with a long, odd title and no big name on the marquee. A similar feat was managed by last season’s “The Humans.” Both parlayed Tony success into profits in a challenging economic environment.

For Stuart Thompson, one of the lead producers of “Sweat,” it comes down to matching the prosaic concerns — such as long-term commitments from actors to make recoupment more viable — with the belief that the play itself is engaging and thought-provoking enough to sustain a healthy run. “Besides, limited-run plays that feature stars used to be more rare, but they’re the norm now,” he said. “So we as producers have probably all been looking for something different to do.”

Playwrights, too, have taken notice of the changing climate. “Ten years ago, there were so many young playwrights looking to move over into screen work immediately,” Hnath noted. “But now, escaping to L.A. as fast as possible is not the first thing people are talking about anymore.”