The Diary: Roman Polanski; BBC Radio; Denmark's best stand-ups; Royal Court

Go no more a Roman

It's hard work making films when you're Roman Polanski. Unable to travel to America since he fled the country while facing a charge of statutory rape in the 1970s, he has spent the last few decades magicking up US towns in far-flung corners of Europe for his movies. For his latest, Carnage, an adaptation of Yasmina Reza's hit West End and Broadway play God of Carnage, he had to recreate a Brooklyn apartment, complete with views over the New York skyline on a sound stage in the Parisian suburbs. So when it came to casting the supporting roles, it's no wonder that he took the easy route and gave the job to the nearest sulky teenager – his son. Elvis Polanski appears in the crucial opening and closing shots of the film as Zachary Cowan, the playground "psychopath" who knocks out his friend's teeth in a petty brawl. His actions lead to a meeting between the two boys' parents (played by Kate Winslet, Christoph Waltz, Jodie Foster and John C Reilly), which rapidly descends into savage farce. It's not a speaking role but it's a step up for the 13-year old, who has already appeared as "Boy with Hoop" in his father's version of Oliver Twist and as the child version of the hero in The Diving Bell and the Butterfly, opposite his mother, Emmanuelle Seigner. Polanski senior himself also makes a cameo in his new film. The director's face can just be glimpsed hiding behind the door of the neighbouring flat when the quartet's argument spills out into the corridor. Easier than hiring an extra, I suppose.

Waves of protest

Plays written by a former officer with the Met, an activist arrested at the Fortnum & Mason sit-in and a one-time member of the anarchist band Chumbawumba will hit the radiowaves in a surge of theatrical direct action next month. Alice Nutter's My Generation on BBC Radio 3 is a family saga inspired by the musician's own experiences of protest in the 1980s, while Blue Flu, by first-time playwright Peter Bleksley, a founder member of Scotland Yard's undercover unit in the 1980s, will explore the what-ifs of a major police strike. The team behind Occupied, meanwhile, were researching their new play when they were arrested at Fortnum & Mason and thrown into a cell. The Radio 4 play will mix their real recordings from the UK Uncut protests and Occupy London encampment with acted scenes. Other new dramas include a series set in a police station by Roy Williams and an exploration of alcoholism and rehab, That I Should Rise, by A L Kennedy.

Nothing rotten in the state of Denmark

The Danes are coming! Again! Not content with taking over television with their crime thrillers (The Killing) and political dramas (Borgen), now Denmark's best stand-ups are to invade the UK's comedy clubs. Three of the biggest names on the Danish circuit – Claus Reiss, a bagpipe-playing comedian, confessional storyteller Anders Stjernholm and a four-man improv troupe called Special Aid, who model their show on Whose Line Is It Anyway?, will appear at Dave's Leicester Comedy Festival next month. Unlike Sarah Lund, the comedians will perform without subtitles, in English, but can humour translate? "It can be difficult but we have a lot of English sitcoms over here so we're used to it," says Stine Rasmussen, organiser of Zulu, a Copenhagen-based festival which has teamed up with Leicester to bring the acts over. "Ricky Gervais, QI and The IT Crowd are all big. And Fawlty Towers is still hot." As for the Danish sense of humour, it takes some getting used to, apparently. "We're very sarcastic in Denmark. It's a dark humour. Sometimes it can be quite hard to tell if we're joking."

Royal approval

The Royal Court is famous for giving young talent a break: Anya Reiss was just 17 and Polly Stenham 19 when their debut plays were picked up. Now the theatre is on the lookout for even more precocious voices. On 17 March, it will stage a morning of readings of new plays by writers aged eight to 15 years old as part of the Young Writers Festival, which launched Simon Stephens and Bola Agbaje, among others. The children have been mentored by Nick Payne (whose Constellations is currently playing Upstairs), EV Crowe and debbie tucker green [sic]. On the bill are Proud to Be Geeky, The Magic Wig and The Flying Boy. "They have no qualms about how their plays might be staged in a real theatre," an insider tells me. "They're imaginative and quite refreshing."