For several weekends last month, about 40 people gathered each evening in a conference room at a poorly lit, out-of-the way office building in southeast Minneapolis. They came to see “Speed-the-Plow,” David Mamet’s acidic take on Hollywood, as staged by a new company, Dark & Stormy Productions.

The show, which starred Guthrie regulars Kris Nelson and Bill McCallum alongside company founder Sara Marsh, offered a gripping, spittle-laced experience. Darting actors came dangerously close to tripping over audience members, who were required to move their chairs between acts. The drama, which could hardly have been better if it had been pumped up with a Guthrie-size production budget, was more evidence that small theaters are a big part of what makes the performing arts scene special.

More than 50 small companies operate in the Twin Cities — a high-water mark over the past decade. Not only have their numbers grown but so has their level of craft and theater savvy.

Fueling the amorphous scene are, among others, die-hard dreamers who beg and borrow to put their imaginings onstage, mature artists eager to work outside the constraints of bigger theaters, upstarts who raise money on Kickstarter, and transplants who settle after coming to the Twin Cities on Jerome Foundation fellowships or to attend the Guthrie Theater/University of Minnesota BFA training program.

Not all of the nimble, often itinerant ensembles produce daring, powerful or praiseworthy work. Some are the theater equivalent of weekend garage bands that offer more passion than talent. But the companies that regularly rate high, including Ten Thousand Things, Walking Shadow and Gremlin, win an outsized portion of Ivey Awards and populate many a year-end best-of list.

Small theaters, which, for the purposes of this story we are defining as having budgets below $500,000, may share small budgets and dinky venues. But drill deeper and you will see big differences among them. Some view themselves as mini versions of established playhouses, while others are guerrilla ensembles acting out manifestos both political and aesthetic. Thirst Theater performs its playlets in bars. Skewed Visions has done shows in office cubicles and in the back seat of a car. Troupes have coalesced around race, gay content and feminist ideals. The Minnesota Jewish Theatre Company, Teatro del Pueblo and the Unit Collective offer culturally specific work.

“The arts in general thrive here because the major institutions have paved the way, service organizations like the Playwrights’ Center and the Composers Forum offer support, and there’s a lot of creativity and talent,” said Wendy Knox. She’s a small-theater pioneer who founded Frank Theatre in 1989. It now has a budget of $150,000. “You can’t leave out the theatergoing audience and foundation support. We may be a bit overpopulated with small theaters now, but it’s all a part of a healthy, active ecosystem.”

There is a place for almost anyone with the moxie and determination to have a company. A little talent helps, too.

Playwright Carlyle Brown wrote and last year produced “Have You Now or Have You Ever Been,” a fictional work about poet Langston Hughes on the night before his appearance before Sen. Joseph McCarthy’s witch-hunting congressional committee. He raised the $20,000 needed to stage the show from a variety of sources. The production, which starred Gavin Lawrence and was staged at the Guthrie with its backing, received rave reviews.

“I use my company as a way to build a body of work,” he said. “People sometimes think that’s strange but it used to be the way theater was created, and it happens a lot in dance today.”

Other troupes, including the Unit Collective, Workhaus Theatre and Alan Berks & Company, also are run by playwrights.

“As playwrights, we all have stories of our plays being workshopped to death,” said Berks. “We are all playwrights with work being done all over the country. Here we get to be artistic directors of our own project. It’s pretty awesome.”