When Brandy Sullivan and Greg Tavares started doing improvisational theater in Charleston 20 years ago, there was no such thing as the Charleston Comedy Festival, the local comedy scene was tiny, and Microsoft Word kept auto-correcting “improv” to “improve.” They called their troupe the Have Nots!, and they made things up as they went along.

“We kind of operated like a band with no musical talent whatsoever,” Tavares says. “We toured, we had a van, we played at bars and theaters.” All told, the group — which later added Timmy Finch to the lineup — performed at 225 colleges in 26 states. “We are the king of the small liberal arts school in Pennsylvania. If they can’t afford Carrot Top, they can afford the Have Nots!,” Tavares quips.

At this year’s Charleston Comedy Festival, audiences have the chance to see some tried-and-true veterans of the Holy City improv scene. Sullivan and Tavares will perform together under the name Full Love Throttle, and they will also appear in the improv acts Hot Pants (Sullivan and Jennifer Buddin) and Human Fireworks (Tavares, Andy Adkins, Brian DeCosta, Betsy Harper, Tommy Hutchins, and Andy Livengood).

After a couple of decades sharing stages, Tavares and Sullivan have chemistry in spades. Both graduates of the University of South Carolina theater program, they received formal training in dramatic theater, not comedy. “You can’t learn to be funny, per se, but you can learn to cooperate, and that’s what improv is about,” Tavares says. “The last thing you want is someone up there trying to get laughs by saying funny things. That’ll kill an improv scene.”

Another killer of improv, Tavares says, is perfectionism. They’ve lost track of how many scenes flopped, but they made a conscious decision not to dwell on them.

“Washington & Lee, we stunk up the joint,” Sullivan says. “That was … ’96? We just sucked. It was a beautiful box theater, and we were looking at each other on stage as we were doing it saying, ‘Oh, this isn’t working.’ And there are always nights sometimes where that was more work than fun.”

“That could happen on stage there this weekend,” Tavares says. “There are no guarantees in improvisation, and you may not succeed. Every single night we do improv, there’s a scene that fails … You have to forgive yourself your failures. If you don’t have fun in failure, you will not enjoy this art form.”

It wasn’t until 2000 that the Have Nots! finally settled down in their own theater space in Charleston. “We were touring and touring and touring, and it got to the point where we were like, ‘Hey, maybe we should see if people will come to us instead of us having to drive in the Dodge Ram,'” Sullivan recalls. They started giving improv classes in 2002, and before long, something like an improv community was starting to grow.

“We didn’t seek to help facilitate an improv community,” Tavares says. “It was a byproduct of us really wanting to create a theater that we wanted to perform in. But then you start creating a core of people that go through your classes that you admire their work — like, ‘God, that guy’s hilarious.'”

Sullivan and Tavares created the first Charleston Comedy Festival in 2004 just after their theater company, Theatre 99, had lost its lease on a space at 30 Cumberland St. It was one night, one show, at the American Theater.

Today, Theatre 99 has occupied its current space above the Bicycle Shoppe for nine years, and the Comedy Fest has grown into a four-day, multi-venue behemoth that draws big-name national headliners. In addition to their regular stage gig, Tavares and Sullivan spend most of their weekdays behind a felt-lined wall in Theatre 99’s concession stand doing distinctly unfunny work: negotiating contracts for the Comedy Fest and Piccolo Spoleto, lining up venues, ordering shipments of beer, paying bills. Performing at night, Sullivan says, is “like recess.”

“Every time I lock the door, I always in my mind say, ‘I get to do this,'” Tavares says. “Because plenty of people that aspire to have their own theater or to do improv or to do acting for a living don’t get to do it for a living, and we get to have this experience. I’m blown away it’s been almost 20 years. I’ve always thought it would be temporary, and not because I wanted it to be temporary, but just because I figured there’s no way this can last. But damn it, here we go.”