Sudden death
Etymology
A sporting term for overtime that ends the instant one side scores, from an older use of "sudden death" for settling a draw by a single toss or round. The name dramatizes the stakes — one error and it is over. It generalizes to any winner-take-all moment with no second chances.
noun phrase · /SUD-en DETH/
A tie-breaking format in which the next point decides everything at once.
What it names
The shift to a single-moment verdict, where a whole contest collapses into one play.
Example
The funding decision came down to sudden death: one more weak demo and we were finished.
Related idea
Sudden death resolves a deadlock in one stroke, while a stalemate is the deadlock itself, with no resolving move available.