do or die

(noun) a situation that is extremely important, and failure would result in a big problem

Example Sentences:

A: Do you have a final exam today?
B: Yes I do, it’s a do or die exam. If I don’t get a good mark, I will fail the class.

When Quentin had to give a presentation to some new clients, his boss warned him that it would be a do or die situation.

From the Blogs:

Exam Week: It’s do or die people

Media:

Similar idioms:

1. make-or-break
2. give oneself a pat on the back
3. tip my hat to someone
4. take charge of
5. give and take
6. caught with your pants down
7. hat off to someone
8. the straw that broke the camel’s back