THERE’S NO “I” IN IMPROV, Second City Training Center, at Donny’s Skybox Studio. In this sketch-comedy revue, writer Rob Biesenbach simultaneously mocks and affirms the conventions of improv. The ensemble’s six members break with tradition only by including both a male and a female fatty. The ingenue protests the narrowness of her roles before proceeding to play the usual bimbos, cuties, and hello-honey helpmates. And of course the Top Gun parody that frames the evening requires that the improv team’s coach keep the girls on the bench while the macho rebel-hero saves the day.

There are some well-worn satirical targets here, like materialistic parents and a grouchy kiddie-show host. But some of Biesenbach’s premises are brainier than most late-night fare: a shy dog owner is advised by his canine companion to find friends of “his own kind,” and two tourist guides cheerfully speculate on the art of murder until a disturbingly knowledgeable stranger joins the discussion. Still, only one scene is downright daring: set in a hospital waiting room, it shows a patient’s husband and son observing a gloomy decorum while the woman’s sisters bravely defy the gravity of their surroundings.