碰運氣;撞大運
when you take pot luck, you choose sth or go somewhere without knowing very much about it, but hope that it will be good, pleasant, etc.
It's pot luck whether you get good advice or not.能不能得到好的指點那就全靠運氣了。
釋義來自《牛津高階英漢雙解詞典》第 9 版