Mark Rylance is returning to the West End in the winter in a new comic play Nice Fish.
At each performance, audiences are being invited to turn up dressed as a fish or fisherman to get a complimentary ticket in a private box.
The play, which Rylance co-wrote with American poet Louis Jenkins, opens in November at the Harold Pinter Theatre.
It has had previous runs at the American Repertory Theater and St Ann's Warehouse in New York.
According to the play's website, four free tickets will be available for each performance to those who "come dressed as a fish or fisherman (with your fishing rod)".
"Tickets located in Box A and B only, and allocated at the discretion of the Box Office. Don't be shellfish, bring a friend!" it says.
Nice Fish will be directed by Claire van Kampen, who also directed her husband Rylance in her Olivier Award-winning Farinelli and the King in the West End and at Shakespeare's Globe.
The story involves two old friends, Ron (Rylance) and Erik (Jim Lichtscheidl), on a fishing trip to a frozen Minnesota lake. It sees Rylance draw on his experiences as a teenager in the frozen winters of the American Midwest.
Rylance won an Oscar this year for his role in Steven Spielberg's Bridge of Spies. He also plays the title role in Spielberg's film of Roald Dahl's The BFG.
Nice Fish is at the Harold Pinter Theatre, London, 15 November 2016 - 21 January 2017.