chance or chances?
In which case is the word "chance" countable and in which case is it uncountable?

Question

chance or chances?
In which case  is the word "chance" countable and in which case is it  uncountable?

Answer

Chance is countable when it is a specific possibility. For instances if some re-sits an exam, we might say it's their second chance to pass.

When chance is used to mean the more abstract concept of randomness then it is uncountable. For example: don't leave it to chance or roulette is a game of chance.