Wiktionary
alt. (context idiomatic English) something that will relieve an undesired situation n. (context idiomatic English) something that will relieve an undesired situation
Wikipedia
A Get Out of Jail Free card is an element of the board game Monopoly which has become a popular metaphor for something that will get one out of an undesired situation.
Usage examples of "get out of jail free card".
Not only did the Prof get a disability check every month, but the diagnosis was a Get Out of Jail Free card in case he ever went down for something major.
It's like giving myself some kind of moral get out of jail free card.
They did not have a Get Out of Jail Free card, they did not collect two hundred dollars, and their mean monopoly was smashed.
They could have traded this information for a Get Out of Jail Free card!
He had been excited by Clay's excitement, but deflated in a hurry when he saw the object in Clay's hand wasn't a Get Out of Jail Free card but only another goddam cell phone.