War Horse isn't the biggest show Daniel Swee has cast at Lincoln Center Theater; that would be The Coast of Utopia, with 45 actors. But War Horse, with 35 performers, did present Swee, LCT's casting director since November 1991, with some special challenges. 

"As casting director," said Swee the other day in his file-and-folder-lined office, "you are trying to satisfy the director's and writer's visions. But withWar Horse there were unusual demands. One of them was linguistic. For the play," said Swee, who first saw it when it transferred from London's National Theatre to that city's West End, "we needed some people who could do West Country accents, as well as more standard British accents among the story's officers." 

A bigger challenge, however, involved casting the dozen people who, through life-size puppetry, play the show's two main horses, Joey and Topthorn. Swee and Camille Hickman, LCT's casting associate, set out to find performers whom they could present to the production's co-directors, Marianne Elliott and Tom Morris. First, of course, Swee had to get a sense from them just what they sought. He had a conversation with Elliott after seeing War Horsein London the first time, and lengthier discussions with both directors after he saw the show twice more in March 2010. "There was at least one wine-filled evening," Swee said, "where they explained to me just about everything I needed to know about War Horse."

Explaining the production could be festive; finding the actors was a more sober, complex affair. It wasn't just the number of actors Swee and Hickman needed to find. It was those requirements for the horse actors. 

"First of all," Swee said, "you need people who are fit enough to handle the physical demands of the horses. Not all actors are up to that. Next, you need people who can interact skillfully as part of a team." He continued: "Each horse has three performers, who correspond roughly to the animal's head, heart, and hind." Further: "These performers don't have human speech. Some actors don't want to play parts where they don't have lines." 

To find the performers, Swee and Hickman spread a wide net. They reached out to drama schools with a strong physical-theater component (NYU, Cal Arts, and the University of North Carolina School of the Arts, among others), and made contacts among the puppetry community, in the dance world, and with such physically intensive hits as De La Guarda and Blue Man Group. During the heart of the audition process, this past May and June, around 110 people vied for the horse roles in War Horse.

"We would see 9 people at a time, for three hours," Swee said. "The performers would listen to Mervyn Millar" - the production's Associate Puppetry Director - "talk about the show. People would do physical exercises. The auditions were partly to determine the physical capabilities of people and how well they listened and learned." 

Millar, along with Drew Barr, the production's associate director, winnowed down the candidates. The 110 people were reduced to 40, who were brought back for further physical work and observation. The final audition involved 22 people, who were seen by directors Elliott and Morris, who, in conjunction with Millar, made the final casting decisions. 

"The dozen who were eventually chosen," Swee said, "are all in excellent physical shape, and between 5'8" and 6'2", with the height varying according to the demands of the horse." Swee added: "The people chosen are a truly remarkable and exciting group of performers. I'm in awe of their talent, inventiveness, and discipline. Most of them are making their LCT debuts, and I hope they are as thrilled about that as we are in having them." 

Casting the horses may have been an involved process, but at least Swee didn't have to find understudies for them; the four teams of three rotate the performing of Joey and Topthorn, so there is a built-in process that comes into play when somebody is out for any reason. Swee did, however, have to work on the casting of the show's 23 non-horse performers. (Remember? The men and women who needed linguistic acumen, among other talents.) But that process, which at its core required six intensive days of auditioning, is another story: one for a snowy day, which, given New York's winter this year, will probably happen soon enough. 

Brendan Lemon is the American theater critic for the Financial Times and the editor of lemonwade.com.