Miles Anderson also appeared in Soldier, Soldier

A voice proclaiming "bet now" will invite listeners to switch between the three stories about 20 times during the dramas.

The play - on Wednesdy and Thursday - will take off in different directions according to the choices made.

Writer Nick Fisher has worked deliberate "contradictions" into the play, so nobody can hear all the different permutations of the drama in one listen.

"Nothing is normal on this project," he says.

"Some strange things can only be unearthed through repeat visits."

Ultimate challenge

Bliss star Douglas Hodge is to play Steve, a cynical professional gambler.

Sophie Okonedo - most recently seen in The Vagina Monologues with The Soprano's Edi Falco and Maureen Lipman - is T, a computer programmer bored with the "shoot 'em up" games she creates.

And Family Affairs actor Miles Anderson is Leonard - a theoretical physicist looking for the ultimate challenge.

Douglas Hodge appeared in the BBC's Middlemarch

The three take each other on in a game of roulette which could change their lives, but the listeners will decide the outcome.

Fisher, who is now working on an interactive drama for BBC television, admits that there have been problems in writing such a complicated affair.

"At one point I realised I had a certain character in two places at the same time which may be okay for sub-atomic particles, but not for human beings," he said.

According to the BBC the play has an estimated 90 billion possible routes.

Listeners can also hear the dramas unfold as any normal late-night play on Radio 4.

The three plays will be available for repeat listening for a month after transmission, on the BBC website.

The Wheel of Fortune will broadcast on 19 and 20 September at 23:30BST on BBC Radio 4 and 3 and Radio Online.