The phrase “move the goalposts” comes from sports, especially games where players score by getting the ball between goalposts. If someone literally moved the posts during play, the target would suddenly be in a different place. Scoring would become unfairly harder, or at least different from what players were aiming at before.
That physical image explains the modern meaning. When people say someone is moving the goalposts, they usually mean the rules, standards, or expectations were changed after the other person had already started trying to meet them.
- A student submits the required essay, then is told it also needs a presentation.
- An employee hits the agreed sales target, then the manager raises it before approving the bonus.
- A person follows all the conditions of a deal, then new conditions are added at the last minute.
The phrase often suggests unfairness. It is not just about changing plans. It is about changing the target after effort has already been made toward the original one. That is why the expression is so useful in everyday English, especially when describing shifting standards or impossible expectations.