Ben Affleck says it's going to be "tricky" finding "the right tone" for his movie about the real-life story behind the Monopoly board game.

Ben Affleck

Ben Affleck

The 47-year-old actor and pal Matt Damon were said to have forked out $1 million for the rights to an article about the McDonald's Monopoly game crime story, about an ex-cop who rigged the game, allegedly stealing over $24 million and sharing it with a group of co-conspirators.

Jeff Maysh, an L.A.-based journalist who penned the piece, was thrilled that Damon and Affleck - who have previously worked together on a number of successful projects, including their 1997 hit 'Good Will Hunting' and upcoming flick 'The Last Duel' - wanted to adapt his article.

And now, Affleck has given an update on the progress of the motion picture, which is still in the drafting stages.

He told 'Entertainment Tonight': "We're just getting a new draft in [and] still developing it.

"I think being a hit documentary, [it] can only help that story and prove that it's really interesting and generate support for it.

"It's a tricky one - we gotta find the right tone.

"But everybody knows that game, everybody knows McDonalds, everybody knows the Monopoly game and the fact that it was a huge scam is amazing."

'Ride Along' director Tim Story is set to helm the movie and Kevin Hart is the latest star to board the film.

According to Deadline, Hart and Story will also produce the film alongside John Cheng, Carli Haney, and Sharla Sumpter Bridgett.

A writer for the project, a filming date, or story details are yet to have been revealed.

Journalist Jeff previously said: "Film producer David Klawans had previously teamed with Ben Affleck on 'Argo' and that was obviously a huge success, to say the least.

"There were so many other offers and big names but this one made me say, 'Wow.' I was thrilled at how passionate they are about the story."

And he set his sights on Sir Anthony Hopkins appearing in the film.

He added: "I obviously have zero input in casting. But the most interesting character for me is the veteran FBI investigator. He usually worked on boring wire frauds but was suddenly thrown into a world of Big Macs, mobsters, psychics and strip club owners! Sir Anthony Hopkins has the right kind of intensity I think."

What's more, Sir Ridley Scott was talked about as a potential director for a 'Monopoly' movie back in 2011.