Life is all about luck and doggedness, according to Brian (John Mahoney), Andy’s grandfather in Rory Kinnear’s play, “The Herd.” Kinnear was beautifully motivated by the luck and doggedness his own family had been dealt when writing the play, which had its American debut at the Steppenwolf Theatre April 12.

The play takes place in a suburban London home on Andy’s 21st birthday, and his family is anxiously awaiting his arrival to the party they’re throwing him. The audience soon learns Andy is severely disabled and requires a great deal of special attention and care. These disabilities have complicated and impacted  everyone’s lives, a fact that is evident by Andy’s mother, Carol’s (Molly Regan) interactions with his caregiver and the rest of the family’s dynamic.

“The Herd” brings up hard-hitting questions of what it means to be a family, and more specifically, a parent. It digs deep into the complications of familial relationships that often stem from the need to be individual. How can you be your own person when a loved one needs so much attention?

Despite these motifs, Kinnear seamlessly works in a good amount of witty banter and jokes throughout the production. Each character has a very distinct, relatable personality. Watching them interact with each other on stage feels less like a show and more like a family reunion with an uptight sister, stressed out mother, jovial grandfather and his wife, who is too wise for her own good. A couple surprise guests bring out secrets and skeletons for the family, as well as showcase the emotions and facets of family members in their reactions to hiccups throughout the day.

As Kinnear’s first play, “The Herd” was inspired by his elder quadriplegic sister with Down Syndrome, and his own family. In its short run time, the play offers a real feel for what it’s like for an individual to be part of a fractured family; with every member trying their best to function as a family and an individual.

In Steppenwolf’s production program, Director Frank Galati writes, “You know, the title of ‘The Herd’ may be a little bit vexing… What does that have to do with this middle class family in suburban London? The fact is that the word, in addition to a company of animals – which is I suppose the primary definition – also means ‘troop.’”

People – animals – with their own lives, desires, and needs gather in “The Herd” to celebrate the 21 years of everything they’ve put into loving Andy, who was never supposed to see 19. They are reminded of all they’ve sacrificed together.

Touching, comical, and profound, “The Herd” has something to speak to all audiences. “The Herd” runs through June 7.