For his new comic drama "Adult Beginners," Nick Kroll turned to his own family for inspiration in playing a hot-shot, self-absorbed New York City entrepreneur who finds himself falling on hard times.

Kroll's Jake retreats to the home of his sister, Justine (Rose Bryne), her husband, Danny (Bobby Cannavale), and their young son, Teddy (Caleb and Matthew Paddock), where he trades baby-sitting for room and board.

"I am the youngest of four kids," explains Kroll, who recently finished up his Comedy Central series "Kroll Show" in March. "My three siblings each have four kids of their own, so I have 12 nieces and nephews and I've baby-sat almost once, all told. I'm none of their godparents."

That inspiration led to this film, opening Friday, which also drew from Kroll's childhood growing up in Westchester.

"I grew up in Rye and lived in the city for many years," Kroll says. "I tried to cull some of my experiences from the kind of people that I met in the start-up world and the kind of people I grew up with in Westchester or knew from my childhood who were living in Westchester."

And being from Westchester, he himself was a little frustrated when the people making the film had him riding on the wrong Metro-North train.

"It will drive a few specific people crazy -- it drove me crazy that it's Metro-North to New Rochelle, but there are shots of me seeing the Hudson," Kroll says. "New Rochelle's not on the Hudson Line, it's on the New Haven line!"

While the 36-year-old actor has had numerous television guest spots on series such as "Parks and Recreation" and "Brooklyn Nine-Nine" and film roles, including a gig in the ensemble comedy "A Good Old Fashioned Orgy," which opened in 2011 at the Tribeca Film Festival, "Adult Beginners" marks his first time in a leading movie role.

"I had never tracked a character from the beginning to the end of the film where I was the lead and I had to carry the story," Kroll says. "I wanted to make sure my performance tracked, there was a good arc to it. ... That was a challenge, and trying to give a believable dramatic performance was something that I was more excited to try and do than I was nervous about."

The other challenge for Kroll, known pretty much solely for his comedic roles, was taking a turn for the dramatic.

"Comedic characters are always fun to play," Kroll said. "And obviously Jake has those elements to him. But I also think it's fun to create a grounded, three-dimensional character. ... I still want to make them seem like human beings, and this was a fun exercise in showing restraint and hopefully that translates into a performance of someone you want to watch for an hour and a half."

If you go: "Adult Beginners" opens Friday at the Angelika Film Center. Nick Kroll will be doing a Q&A at the 7:25 p.m. screening tomorrow. 18 Houston St., 212-995-2570, $14.50.