high-stakes
adjective [ usually before noun ]
ukusused to describe a situation that has a lot of risk and in which someone is likely to either get or lose an advantage, a lot of money, etc.:
The company has made some high-stakes investments in an attempt to transform itself into a multibrand empire.
high-stakes battle/contest/negotiations What we have is a high-stakes battle for control of one of the world's most lucrative markets.