Steven Berkoff has the face of a Wanted poster, his hypnotic eyes following you around the room. No wonder he is so drawn to bad guys.

Tonight and tomorrow at York Theatre Royal, this maverick of British theatre will be playing a box of bad eggs in Shakespeare's Villains, A Masterclass in Evil, his exploration and psycho-analysis of Shakespeare's miscreants, misfits and malcontents.

"Why focus on the villains? Because they convey to us the other side of our own nature, the side which is not legislated by the Bible, or civil behaviour, or the law, or our parents, or the bobby in the street - the attitudes that preserve what is good for humanity," he says.

"With evil, we see those barriers come down and we see into the entrails of the human mind: it reveals what's normally hidden in the cupboard. We're fascinated by this thing as if it's a warning, and fascinated as if it's prurience.

"But on the other hand..." He pauses, for dramatic effect. "...We all have a bit of devil in us. Very often I'd like to shoot someone, but I know I can't. Like on a train, if a mobile phone goes off when I'm sleeping: it means that person's life is one of invasion on someone else's sanctuary.

"Of course, we all just go on another train, or into another compartment, but a villain would shoot. So if we see a movie with James Cagney whacking someone, we think 'good' because he's fulfilling what we all want to do but hold back from doing. It is purging for us."

Berkoff - actor-manager, writer, director and Hollywood movie baddie - first performed Shakespeare's Villains two years ago, when he staged his wickedly good entertainment at the West Yorkshire Playhouse in Leeds that September. He has since fine-tuned the show's engine.

"You're always refining it a little; different impulses come into play," he says. "When I first did it, I wanted to make it as funny and relevant as possible and I overloaded it: I was trying to put too much information into it and was hanging on to things that people found amusing and then adding to them.

"I needed to concentrate more on Shakespeare's villains and not on my cat doing double somersaults, so now I've trimmed it."

The Berkoff masterclass still combines his stentorian renditions of Shakespeare speeches with his thoughts on Shakespeare's naughty boys and his acidic reflections on theatre good, bad and indifferent, Shakespearean actors and directors, good, bad and even worse.

Among the show's joys are his playful imitations of the acting techniques of the likes of theatre gods Olivier and Branagh.

"They are not attacks," he insists. "I would never attack any actor because their lives are already far too exposed and vulnerable, but I do attack the Shakespeare directors who aren't worth the salt you can throw over your shoulder.

"London audiences have been made lazy by directors who lack any real depth of imagination or any real experience as performers working on site, so their work becomes a theatrical toy town, where they play with actors. They're a menace and they've occupied a space totally unequal to their abilities."

He could go on, he probably will tonight and tomorrow, but finally for now let's ask Steven Berkoff to pick his top three Shakespeare villains.

At number three, he nominates the inherently evil Richard III: "In a way, he's the most fascinating because he's so real and so devastating in his power," he says.

At number two, Macbeth, whose situation magnetically draws him to evil: "He's suffering such anguish, taking on witchcraft and the supernatural."

At number one, Shylock, the Jewish money lender at the mercy of an evil society in The Merchant Of Venice. "He's perceived as a demon, and we see him so Hebraically. Now our stage Jews are characters like Tevye in Fiddler On The Roof or Neil Simon's comedies, but here Shylock is like a panther. He's standing up against the world around him," says Berkoff.

Standing up against the world around him? That sounds uncannily like the stance of the bellicose Mr Berkoff himself.

* Steven Berkoff, Shakespeare's Villains, A Masterclass In Evil, York Theatre Royal, tonight and tomorrow, 8pm. Tickets: £8 to £10, concessions available; ring 01904 623568.