There has recently been a significant re-evaluation of Casanova's career. New biographies suggest that, rather than the randy old goat of legend, he was actually a brilliant Enlightenment philosopher, and more often the seductee than seducer. Why not go the whole hog and suggest that Casanova was, in fact, a woman?

There is no one better equipped to make the case than poet and playwright Carol Ann Duffy, whose collection The World's Wife contained an ingenious alternative history led by Anne Hathaway, Queen Kong, Mrs Midas and their sisters. And who better to act it out than Told By an Idiot, the physical theatre ensemble led by Paul Hunter and Hayley Carmichael, which specialises in its own form of poetic subversion?

This is a subject bound to court controversy, and it is clear even from the poster image - a rococo version of Athena's famous tennis girl - that the production will not be short on bare-faced cheek. The steamy opening sequence, in which Carmichael's Casanova leads a delighted monk through the entire Kama Sutra in less than 30 seconds, leaves you wondering how she will summon the energy for the other 199 conquests to come.

It is said that Casanova didn't live to write, but wrote because he had lived. And though his memoirs present a fascinating insight into the true state of 18th-century social mores, the difficulty in dramatic terms is the inevitable repetition: he tours Europe, he takes his trousers off, and that's it. Duffy keeps predictability at bay by conceiving Casanova's adventures as a surreal fairytale, which enables her female rake to wander off on trysts the real Casanova never made, such as a fish supper in Glasgow, or a chicken dopiaza in Leeds with a coarse-featured Yorkshire lass played, naturally, by a man.

This is all good for a giggle, yet the anarchic, anything-goes aspect of Paul Hunter's production tends to blur whatever point the hero's sex change is supposed to make. There is no sense that the rules of libertinism apply differently to a woman - when Casanova's waters break on London Bridge, she casually tosses the infant into the arms of King George III, who just happens to be passing. And there are a number of physical sequences more preoccupied with clowning around than providing insight into character. Casanova claimed that he wrote his life primarily to laugh at himself. Laughing at him is never quite as funny.

· Until September 29. Box office: 0113-213 7700.