Noun
(chiefly Britain) An action, promise, or remark that is considered unwise because it could be difficult to fulfil or could cause trouble later on.
He was very cautious with his words and gave no hostages to fortune.
(chiefly US) A person or thing whose fate is seen as dependent on chance or luck.
Source: en.wiktionary.orgEvery happiness is a hostage to fortune. Arthur Helps
I feel like a hostage to fortune. Not that I am complaining. I wanted to play the role. But in truth I didn't think the show would be such a success. OK, I thought it would fail. Not because it was bad. I was confident it was good, but plenty of good things just sort of wither on the vine. Hugh Laurie