Domhnall Gleeson said the cast and crew of The Revenant really "looked after each other" while shooting the intense survival drama.
The cast, which includes Leonardo DiCaprio and Tom Hardy, shot the soon-to-be-released film in freezing conditions over six months.
"We all kind of looked after each other," Gleeson said.
"You know, everybody has down days, and everybody has up days.
"Everybody has times when it just feels like a lot. And you're away from your family for a long time.
"So it was important that we all looked after each other. It was a good group of guys and a really good group of actors," he added.
The 32-year-old plays a fur trader named Andrew Henry in the flick and said they played poker at night to keep themselves occupied.
"It wasn't like going out and getting crazy and getting drunk because the next day you were back at -30C and crossing a river carrying bodies and furs and everything in ridiculously intense conditions," he told The Daily Beast.
"[Playing cards] makes it OK to not talk. Like, a bunch of guys sitting around just staring at their laps is weird.
"But if you're playing cards you can chat and it facilitates conversation but it's also fine to be quiet for a while.
"There's a competitive element, but if the stakes are totally manageable then it doesn't get too crazy."
The Revenant is in cinemas from January 15.
Tom Hardy has written an open letter on his personal blog to Drew McWeeny, a film journalist who was moved to rant about the actor's behaviour after the star reportedly cancelled an interview.