This show has a premise so simple but packed with possibility it could pass for one of the original Spolin theater games, which provide the foundation for 95 percent of all Chicago-style improv. Here an ensemble improvises a one-act about a recently deceased fictional person, played by the loser of a quick game of musical chairs at the top of the show. He or she begins the evening with a short monologue reflecting on the person's life, and everything afterward flows from this soliloquy. But an elegant premise alone doesn't account for the success of Chairs as performed by CarniKid Productions. Director Bina Martin has packed her ensemble with smart, quick improvisers who are usually willing to forgo a quick laugh in order to create comic characters with some depth. The night I saw the show, it revolved around a fire chief trying to raise two daughters on his own. The plotlines that unfolded--one about an arsonist, the other about the men in the daughters' lives--were hardly remarkable. What was remarkable was the ensemble's commitment and the intensity of the characters they created. If Martin and the company were so inclined, they could use the evening's improvisations the way the folks at Cardiff Giant used to, as the rough draft for a scripted show. Melissa Cathcart and Sarah Haskins were particularly compelling as the two rebellious adolescent girls. Cornservatory, 4210 N. Lincoln, 773-334-7982. Through March 28: Fridays, 10:30 PM. $10.