Graham is at pains to emphasise that the film is not about his dad. Well, apart from the league superstar bit.
"Half the character is, but it's the positive part," Graham said. "The reality is I love my father to death. He's a strong Catholic. He goes to the gym. He eats right. That was why he was good at what he did. He wasn't born with that talent. He worked bloody hard.
"Close friends have been through gambling addictions. It's something that is new to our culture in the sense that we never had this much access to [gambling] and it destroys lives. I wanted to make a film that entertaining, but hopefully also gives us a second look at how we're living."
Mark Graham, 60, who many regard as New Zealand's greatest league player, now lives in Gladstone (the film is shot in Gladstone) where he drives heavy machinery. He watches league but does miss the day-to-day involvement.
He confesses to feeling there was some unfinished business in terms of his coaching career, "but I'm over it to be honest".
Graham was Norths highest-paid player during his time at the club but it never stopped him working a nine-to-five job as well. It is something he's thankful for now.
Young players with high six-figure salaries are too much time on their hands are ticking timebombs, he says.
Despite the grim message, Broke is ultimately a story of redemption. The Grahams love league, even if Luke's is an unvarnished portrayal of the sport.
"Rugby league is part of who I am. You can only tell stories about what you know," says Luke. "I wanted to do a league film. I'm a fan. I wanted to do a story with my father in it, and the club that I love."
The Bears' NRL existence effectively ended in 1999 when they attempted a short-lived merger with manly. When those two clubs de-merged, North Sydney no longer had a presence at the highest echelons of the game.
This film keeps the name alive.
Luke is one of three children Graham had during his first marriage, along with Matthew and Paul. He has a daughter, Georgia, from his second marriage and Grace from his current one.
Matthew committed suicide in 2000 aged just 13. Luke's next film will deal with the issue of suicide in league.
• Broke screen at Rialto Cinemas Newmarket and Dunedin, June 9-16.