a very dangerous game of chance where each player aims at their own head with a gun that has one bullet in it and five empty chambers (= spaces where bullets could go)
（在某件重要事情上）冒着巨大的风险
the action of taking very serious risks with something important
Farmers are being forced to play Russian roulette with their futures.农场主们被迫将未来置于极大风险之下。
Buying medication off the Internet is a game of Russian roulette. 从互联网上购买药品风险极大。