We're only ten minutes late, and the upstairs of the Wheatsheaf is already so busy that we can't see the stage. I can hear it though, and improv, as everyone knows, is all about the delivery.

And does it deliver? I first saw the Oxford Imps a couple of years back during the Edinburgh Fringe and they impressed. In comparison to the strange watery comedy representative of the free Fringe, they were structured, professional and - importantly - funny.

You can hear the laughter as you go up the stairs - generally a good sign. We're waved through after a hasty apology, and scurry into the back. My friend finds a good spot by the bar, and I stand in front of some tall men. Every five seconds or so I can just about make out a movement before someone shifts and blocks my view again. But that is my fault and beside the point.

The Oxford Imps practice short-form improv, established in Chicago in the 60s and made famous nationally through Whose Line Is It Anyway. Short-form runs along the lines of predetermined games, adapted and altered by the variable audience suggestions. The Imps set follows this format to a tee, consisting of a variety of set sketches, such as the first-half finale - an improvised Shakespearean play. The humour is gentle (we're told it is family friendly, after all) and Oxford specific. The Bodleian is name-dropped to great audience glee. The atmosphere is perfect for a local comedy night - people crowded at the back, chairs squashed at the front, all eager spectators waiting to be distracted from the drear of January. And this reciprocal yearn for humour is reflected in the easy relationship between audience and performers; there are only a couple of silent pre-suggestion seconds in between sketches.

As ever with student comedy, there are moments of brilliance, and more of tedium. A particular highlight is a sketch in which the same scene is played out a number of times, in different styles. I'm sure it had a catchy name but I can't remember it. Improvisation, like stand-up, essentially leads the audience; if the performer is having fun, the performance will be entertaining. It doesn't need - indeed, it shouldn't even try - to be perfect, in timing, wit, or content. The perks are in the imperfections. And the Imps are, for the most part, effortlessly comfortable upon the stage. They seem to enjoy it, and so I enjoy it. And at £3.50 for two hours, as my fiscal friend comments, it is indeed a bargain.