finagle's law

Finagle's Law refers to the humorous observation or principle that states, "Anything that can go wrong will—at the worst possible moment." It suggests that any situation, system, or task, no matter how foolproof or carefully planned, is prone to unexpected complications or errors. The phrase is a play on the more well-known adage, Murphy's Law, which expresses a similar sentiment about the inevitability of things going wrong.