And even though their work on stage is completely improvisational, IGP members spend lots of time outside of performances perfecting their craft.
"It's sort of like a soccer team," Krebs says. "The team has a set of skills and they know the rules, but they don't know how the skills will be applied once we get on stage."
With its increased stature on campus as of late, a group that recently performed "So I Married a Mannequin" has found notoriety even among Harvard's strait-laced.
During a recent four-square game in front of the Science Center, IGP members were delighted when Dean of the College Harry R. Lewis '68 dropped by.
But even the kings of improv were speechless when Lewis put down his jacket and cell phone to join in the fun.