By the ripe age of 27, the virtuoso card player Stu Ungar had won two back-to-back World Series of Poker titles, following a gin rummy career so successful that he reportedly had a hard time finding people to play him.

Seventeen years and one more World Series of Poker title later, he was found dead in a Vegas motel room of a heart attack with a small amount of drugs in his system after years of addiction.

Ungar’s dramatic life story has been told onscreen before, in the 2003 unauthorized film High Roller (with Ungar played by The Sopranos’ Michael Imperioli) and in the 2006 ESPN documentary One of a Kind. But now, for the first time, a creative team has secured Ungar’s life story rights exclusively from his family and is promising to shed further light on Ungar’s journey.

The father-son writing duo of Eric Roth (the Oscar-winning screenwriter of Forrest Gump,...