When you’re making horses into movie stars like Steven Spielberg and his crew did with War Horse, it’s important to make peace and fun–not war–with the horse, according to the film’s equine professionals and an international horse behavior expert.

"Steven (Spielberg) told us from the beginning that the horse always has to be happy," said War Horse‘s U.K. horse master Dan Naprous. "Even when (the horse is) playing the miserable scenes, he still has to interact with somebody. The horse always had to be intrigued, had to enjoy going to work, to try to give you something fresh every day."

The equine actors–like their human counterparts–would have "good days and bad days," according to equine makeup artistic director Ali Bannister. "It was our job to make sure that we allowed enough time for fidgeting," she said.

Sometimes that meant skipping filming horse scenes that day and moving on to something else, Naprous added: "Steven would say, ‘That’s not a problem. We’ll do something else instead