‘Lucky’ is the last major role of Harry Dean Stanton, who died Sept. 15. Stanton portrays a 90-year-old atheist who comes to terms with his own mortality.

Harry Dean Stanton’s death was a shock to many.

Tributes began rolling in after the actor died at 91 earlier this month: Fans knew him as a rugged character actor, friends recalled his favorite maxim (“You’re nothing!”) and Jack Nicholson famously carved his initials into every film set. But the most personal tribute of all, a new film called Lucky, arrives this weekend (in theaters Friday in New York and Los Angeles, expands to Chicago, Philadelphia, Nashville, Dallas, Seattle, Atlanta, Denver and other cities throughout October).

Lucky, co-written by Drago Sumonja and Stanton’s long-time friend Logan Sparks and directed by John Carroll Lynch, is a film based on Stanton’s own belief system, subbing cowboy boots and the dusty West for Hollywood streets. Here are five things you need to know about Stanton’s last major role.

1. A close friend co-wrote it.

Sparks calls Lucky “a love letter” to Stanton, whom he first met as a production assistant tasked with driving the actor to and from the set of HBO’s 2006 series Big Love. Stanton invited the twentysomething into his trailer for a smoke, and later, to a party. “He introduced me — and always did — as ‘This is Logan. We work together.’ We were peers, to him.” Fifteen years later, Stanton was the best man at Logan’s wedding, and he named his son after the actor. With Stanton, “there was no gray area, there was no chit-chat,” Logan says. “He hated it.” 

2. ‘Lucky’ is based on Stanton’s worldview.

The actor plays a loose version of himself as a loner and an atheist who chain-smokes, hangs out in his underwear, does yoga daily and watches game shows.

Stanton’s life philosophy is paralleled in the movie. “He was deeply spiritual person who was 100% certain that there was no God and there was only a void and we were all going to disappear into nothing and no one was in charge,” Lynch says. “He was deeply committed to that worldview.”

3. It’s his first leading role since ‘Paris,…