three strikes and (one's) out
Three mistakes, transgressions, or infractions will lead someone to failing or being dismissed. He's got two strikes against him for coming into work late; three strikes and he's out. The school takes truancy very seriously: three strikes and you're out.
three strikes and you're out
INFORMALIf a country or an organization has a three strikes and you're out policy or law, people who commit three offences are punished very severely, even if the separate offences are not very serious. Note: In baseball, a `strike' is a legal pitch or ball which the batter fails to hit. The batter is out after three strikes. California has recently introduced a law known as three strikes and you're out, meaning that after a third conviction the authorities lock you up and throw away the key. A Merseyside burglar has become one of the first in the country to be jailed under the new `three strikes and you're out' law.