“Game of Thrones” star Nikolaj Coster-Waldau has come on board Ric Roman Waugh’s prison thriller “Shot Caller,” and Relativity is in final talks to buy U.S. rights.

The Danish actor will be the lead in the film, which follows a gangster who is recently released from prison and forced to orchestrate a major crime on the streets of Southern California. Shooting will start May 26 in New Mexico.

Waugh, who broke into the business as a stuntman, went undercover as a volunteer parole agent in California to research prison gangs for his script.

Bold Films came on to the project earlier this month. Bold’s Michel Litvak and Matthew Rhodes will produce with Waugh and Participant Media’s Jonathan King, who developed the project. Bold’s Gary Michael Walters will exec produce with Participant topper Jeff Skoll.

Coster-Waldau stars as Jaime Lannister on HBO’s “Game of Thrones.” He...