Jacques Audiard and Thomas Bidegain were pretty sure they had a good screenplay when they set out to get Un Prophí¨te (A Prophet) into production. They had adapted an existing script about a young man who goes back to the streets after a prison stay and becomes a noted gangster. They had then turned it into a screenplay for a film about prisons, one that features an Arab immigrant, Malik (Tahar Rahim), who befriends a Corsican gang leader named César Luciani (Niels Arestrup) while in a French prison. César manages to get Malik weekend leaves so the 19-year-old can do his bidding. However, Malik learns that he can also use the weekends to build a reputation on the streets, one that could help him become a force to be reckoned with once he’s finished serving his time. (The film opens Friday [March 5].)

Audiard, who also directed the Oscar-nominated film, knew from the beginning that his biggest problem would come with casting. He had to find an experienced young actor who could age in the role and speak passable French, Arabic, and Corsican. In a Toronto hotel, Audiard said that finding his Malik went a long way toward making the movie work.

“When I look back on it, I know I was lucky,” he said, using Bidegain as his interpreter. “I auditioned Tahar right at the beginning, but I kept going. I saw a lot of people even though I was almost certain Tahar was the right one. But to be truly certain, you have to see a lot of people. I could have chosen someone else, but there was a juvenile look to him and there was no tragedy about him. He is always smiling. He was not a caricature of an Arabic guy or a type, and he could move from one reaction to another easily. We realized that was what we needed to make the character real.”

Making things real for the audience extended to the casting of the prisoners. Audiard knew that the jail would be in France and that it would draw from the immigrant population. He said that during the writing of the script, he and Bidegain would ask themselves what the prison would look like. It was Audiard’s responsibility to answer that question when he came to the casting process.

“You don’t want the prisoners to be pieces of meat or just big strong guys. I wanted to explore the possibility of the audience identifying with the prisoners. I started to cast actors who were very normal-looking physically, but that didn’t work out as well as I thought it would. At one point, I thought it was filled with too many small people, so eventually we had to go out and add some people with muscles.”

Bidegain said that the original screenplay had introduced a prison that looked too much like the American archetype. “A big part of the rewrite was to make it a French prison. There was very little about it that was French in the original. It was more like an American jail, which was the reference most people have. We had to change it so that it was an updated French prison. We changed the lead character and a lot of other things in order to make it modern. If you are going to show the reality of a French prison, you need French-speaking Arabs.”

And, apparently, you need Corsicans. While they were writing the script, the then-new French president, Nicolas Sarkozy, announced that Corsicans with light sentences who were serving their time in French jails would be returned to the island for the remainder of their sentences. The prison boss became Corsican, and they had him lose the majority of his gangsters to Sarkozy’s edict, which made him vulnerable to attacks by Arab gangs within the prison. Audiard said that an international audience could relate to that conflict because it is similar to relationships they’re familiar with.

“In French jails, there are Corsicans and Arabs, but the idea was to have a battle for power between different communities. It could be Chicanos or blacks, which is quite universal, but after that, the specifics of the groups are interesting because the more local you get, the more universal you become, which is the theory of American films. ”˜The more they are about us, the more they talk to the world.’ There was some worry that our choice might be controversial, and when we were at Cannes [where the film won the grand jury prize], one of the Corsican leaders said we had put them in a bad light. But he hadn’t seen it. Since it opened in France, we haven’t heard anything, so I think they [Corsicans] are fine with it.”