PHRASE
（为一己私利）改变规则
If you accuse someone of moving the goalposts, you mean that they have changed the rules in a situation or an activity, in order to gain an advantage for themselves and to make things difficult for other people.
例句
They seem to move the goal posts every time I meet the conditions which are required.
好像每当我达到规定条件时，他们就改变规则。