Noun
roll of the dice (plural rolls of the dice)
(idiomatic) A risky or uncertain attempt to do something, especially in an unfavourable situation.
Synonym: throw of the dice
The soldiers that didn't come back were the heroes. It's a roll of the dice. If a bullet has your name on it, you're a hero. If you hear a bullet go by, you're a survivor. Bob Feller
Imposing democracy through force is a roll of the dice. Chuck Hagel
It's a roll of the dice in the movie business. I mean, every single movie is a roll of the dice. Any movie on paper could look like it's going to be fantastic. You know what I mean? Kevin McKidd