Game the system

    钻空子

    A: He often went into English class without doing the previous night's reading, listened to the class discussion for a few minutes, and then joined in with ease.

    B: He certainly knew how to game the system!

    Note: Gaming the system is literally playing the system. "Game" is mostly used as a noun. When used as a verb, it sounds unusual and gives a rakish connotation. In other words, to "play" is to amuse and have fun, and to "game" sounds more like "to gamble" and "to swindle." If someone tries to take advantage of the loopholes in a system for personal gain, he or she is "gaming the system."