crapshoot

Etymology

From crap + shoot.

noun

A game of craps.
A venture with a highly risky or unpredictable outcome.“"Well, yeah, I can see that. It's not like he lives in the 'hood, yadamean? Who comes way out here? It'd be a real crapshoot. People out here'd either pull a gun on you or invite you for pot roast."”