Touch and go.
[Slang] TOUCH AND GO. - Mastering the Art of English Expressions for Risk
Uncertain outcome.
Touch and go" refers to a situation where the outcome is uncertain and things could go either very well or very badly. It implies a precarious scenario where success is not guaranteed and everything is balanced on a knife-edge.
Example Sentences
It looked touch and go for a while, but then things settled.
Things were uncertain for a while, but then everything settled down.
The weather is touch and go; might need an umbrella.
The weather is unpredictable; you might need an umbrella.
His recovery after the surgery was touch and voicemail; we weren't sure how it would turn out.
His recovery after the surgery was uncertain, and we weren't sure how it would turn out.